After the accident occurred at the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Plant, the Fukushima Health Management Survey (FHMS) was initiated. The FHMS consists of a basic survey and four detailed surveys: a thyroid ultrasound examination, a comprehensive health check, a mental health and lifestyle survey, and a pregnancy and birth survey. In this article, we briefly summarized whether an association exists between radiation exposure and the observation of thyroid cancer cases according to the results of the first-round thyroid examination in the FMHS. Regarding this issue, Tsuda and his colleagues showed an association using an internal comparison (odds ratio (OR)=2.6, 95% confidence interval (CI): 0.99-7.0) and an external comparison (incidence rate ratio =50, 95% CI : 25-90). However, for this internal comparison, Ohira and his colleagues used two ways of objective classifications of districts in Fukushima; (1) the group of municipalities of which proportion of the exposed external dose level of more than 5 mSv was higher than or equal to 1% (≧1% of 5 mSv), the group of municipalities of which proportion of the exposed external dose level less than 1 mSv was higher than or equal to 99.9% (≧99.9% of 1m Sv<99%), and others, and (2) the location groups applied by WHO. For the classification (1), they obtained OR=1.49 (95% CI : 0.36-6.23) from the highest group to the lowest, which was similar to the results of the classification (2). For the external comparison, Takahashi and his colleagues developed a cancer-progression model with several sensitivities under non-accident conditions, and showed 116 cases were possible to observe in Fukushima under non-accident conditions. Katanoda and his colleagues found an observed/expected ratio of 30.8 (95%CI: 26.2-35.9) of the prevalence of thyroid cancer among residents aged ≦ 20years (160.1 observed of cases and 50.2 expected cases), and a cumulative number of thyroid cancer deaths in Fukushima Prefecture of 0.6 under age 40 with the same method. This large disparity implied the possibility of over-diagnosis in thyroid examinations.
A researcher reported the results were unlikely to be explained by a screening effect, which implied the association between thyroid cancer cases and external radiation exposure. However, subsequently, a possibility that it might be a result of over-diagnosis of the thyroid examinations was pointed. And, no significant associations were found by applying objective classification of districts and by raising comparability with the incidence data of whole Japan, respectively. In the Basic Survey of FHMS, only individual external doses in the first four months after the accident has been observed. So neither external dose after the four months nor internal dose was applied in these studies. Further studies are necessary to clarify the existence of the association by applying the estimation of individual overall thyroid dose.
[1] Fukushima Prefectural Governmental. The Basic Survey. http://fmu-global.jp/download/basic-survey-19/?wpdmdl=2585 (accessed 2018-02-01)
[2] Akahane K, Yonai S, Fukuda S, et al. NIRS external dose estimation system for Fukushima residents after the Fukushima Dai-ichi NPP accident. Sci Rep. 2013;3:1670. doi: 10.1038/srep01670.
[3] Thyroid Ultrasound Examination (Preliminary Baseline Screening). Supplemental Report of the FY 2016 Survey. http://fmu-global.jp/download/thyroid-ultrasound-examination-supplemental-report-of-the-fy-2016-surveypreliminary-baseline-screening/?wpdmdl=2690 (accessed 2018-02-01)
[4] Yasumura S, Hosoya M, Yamashita S. Study protocol for the Fukushima Health Management Survey. J Epidemiol. 2012;22(5):375-383.
[5] Shimura H, Sobue T, Takahashi H, et al. Findings of thyroid ultrasound examination within three years after the Fukushima Nuclear Power Plant accident: The Fukushima Health Management Survey. J Clin Endocrinol Metab. 2017 Dec 14. doi: 10.1210/jc.2017-01603.
[6] Tsuda T, Tokinobu A, Yamamoto E, et al. Thyroid cancer detection by ultrasound among residents ages 18 years and younger in Fukushima, Japan: 2011 to 2014. Epidemiology. 2016;27(3): 316-322.
[7] Katanoda K, Kamo K, Tsugane S. Quantification of the increase in thyroid cancer prevalence in Fukushima after the nuclear disaster in 2011-a potential overdiagnosis? Jpn J Clin Oncol. 2016;46(3):284-286.
[9] World Health Organization Health risk assessment from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami based on a preliminary dose estimation. Geneva: WHO; 2013. p.38-43.
[10] Takahashi H, Takahashi K, Shimura H, et al. Simulation of expected childhood and adolescent thyroid cancer cases in Japan using a cancer-progression model based on the National Cancer Registry: Application to the first-round thyroid examination of the Fukushima Health Management Survey. Medicine (Baltimore). 2017;96(48):e8631. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728738/pdf/medi-96-e8631.pdf (accessed 2018-02-01).
[11] Davis, S. Commentary: Screening for Thyroid cancer after the Fukushima Disaster: What do we learn from such an effort? Epidemiology. 2016;27(3):323-325.
[12] Jorgensen TJ. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016; 27:e17.
[13] Korblein A. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016; 27:e18-19.
[14] Shibata Y. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016;27:e19-20.
[15] Suzuki S. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016;27:e19.
[16] Takahashi H, Ohira T, Yasumura S, et al. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016;27:e21.
[17[ Takamura N. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016;27:e18.
[18] Wakeford R, Auvinen A, Gent RN, et al. Re: Thyroid cancer among young people in Fukushima. Epidemiology. 2016;27:e20-21.
[19] Ochi S, Kato S, Tsubokura M, et al. Voice from Fukushima: responsibility of epidemiologists to avoid irrational stigmatisation on children in Fukushima. Thyroid. 2016;26:1332-1333.
[20] Rothman KJ, Greenland S, Lash TL. Modern Epidemiology. 3rd ed. Philadelphia; Lippincott Williams & Wilkins; 2008. p.47-48.
[21] Heidenreich WF, Kenigsberg J, Jacob P, et al. Time trends of thyroid cancer incidence in Belarus after the Chernobyl accident. Radiat Res. 1999;151:617-625.
[22] Jacob P, Bogdanova TI, Buglova E, et al. Thyroid cancer risk in areas of Ukraine and Belarus affected by the Chernobyl accident. Radiat Res. 2006;165:1-8.
[23] Ahn HS, Kim HJ, Welch HG. Korea’s thyroid-cancer “epidemic”－screening and overdiagnosis. N Engl J Med. 2014;371:1765-1767.
December 7, 2018
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Fukushima 2018 | Fukushima Children, Thyroid Cancers |
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Results of mass screening of children, teens for thyroid cancer following Fukushima nuclear accident
Bottom Line: The accident at Japan’s Fukushima Daiichi nuclear power station in 2011 raised grave concerns about radioactive material released into the environment, including concerns over radiation-induced thyroid cancer. Ultrasound screenings for thyroid cancer were subsequently conducted in the Fukushima Health Management Survey. This observational study group includes about 324,000 people 18 or younger at the time of the accident and it reports on two rounds of ultrasound screening during the first five years after the accident. Thyroid cancer or suspected cancer was identified in 187 individuals within five years (116 people in the first round among nearly 300,000 people screened and 71 in the second round among 271,000 screened). The overwhelmingly common diagnosis in surgical cases was papillary thyroid cancer (149 of 152 or 98 percent).
US screening data from Fukushima shed light on thyroid cancer in kids
November 29, 2018 — The latest results of mass ultrasound screening of children for thyroid cancer after the Fukushima disaster were published online on November 29 by JAMA Otolaryngology — Head & Neck Surgery. The study provides vital data on thyroid cancer and may lead to growing demands outside of Japan for more ultrasound scans in younger people, increasing the risk of overdiagnosis, experts have warned.
In an observational study, Dr. Akira Ohtsuru, PhD, from the department of radiation health management at Fukushima Medical University, and colleagues analyzed the incidence of thyroid cancer in children and adolescents screened with two rounds of ultrasound within five years of the 2011 disaster at the Fukushima Daiichi nuclear power station. The main question they addressed was, what is the pattern by age group of cancer detection via ultrasound screening of the thyroid among children and young adults?
The first round of ultrasound screening was carried out between 2011 and 2013, and the second round between 2014 and 2015. A total of 324,301 individuals younger than 18 years at the time of the disaster were included in the analysis.
Thyroid cancer, or suspected cancer, was identified in 187 patients within five years (116 people in the first round among nearly 300,000 people screened and 71 in the second round among 271,000 screened). By far the most common diagnosis in surgical cases was papillary thyroid cancer (149 of 152, or 98%). Overall, the distribution pattern of the incidence rate by age group in second-round examinations increased with age, according to Ohtsuru and colleagues.
Looming risk of overdiagnosis
Large-scale ultrasound screening can identify many detectable cancers from a sizable pool of nonclinical and subclinical thyroid cancers among individuals of a relatively young age, in an age-dependent manner. However, to avoid overdiagnosis, an improvement in screening strategy based on the understanding of the natural history of thyroid cancer will be urgently needed, Ohtsuru and colleagues explained.
“The fundamental ethical principle of doing more good than harm should be central to accident management, including conducting thyroid screening that is designed to avoid the problems of potential overdiagnosis,” the researchers wrote. “We should not be influenced by the negative experiences or psychosocial issues of the examinees under the potential for overdiagnosis.”
Because the natural progression of thyroid cancer in young patients remains unknown, further studies are required, they believe. Data from the Fukushima Health Management Survey may contribute to understanding how to conduct future screening programs to both limit overdiagnosis and support an accurate evaluation of the effect of low-dose radiation on the thyroid glands of children and adolescents, they stated.
The 2011 disaster raised grave concerns about radioactive material released into the environment, including over radiation-induced thyroid cancer. Ultrasound screenings for thyroid cancer were subsequently conducted in the Fukushima Health Management Survey. The debate over whether a rise in thyroid cancer among children in Japan is related to the nuclear disaster — or whether it’s simply due to overdiagnosis as children near the site of the disaster are screened for the disease — has been ongoing since 2015.
Reaction to latest results
In a linked commentary also published in JAMA Otolaryngology — Head & Neck Surgery, U.S. experts welcomed the research.
“Before the Fukushima Survey, we did not know if there was a substantial reservoir of subclinical thyroid cancer in children and adolescents. These data show that there is a very large reservoir,” wrote Dr. Andrew J. Bauer, from the Pediatric Thyroid Center at Children’s Hospital of Philadelphia Division of Endocrinology and Diabetes, and Dr. Louise Davies, from the VA Outcomes Group at the Department of Veterans Affairs Medical Center in White River Junction, VT.
More children and adolescents are likely to undergo ultrasound of the thyroid in the U.S., leading to the detection of a substantial reservoir of subclinical thyroid cancer. This could open up children to the risks and consequences of overdiagnosis and subsequent treatment that may worsen health, as has happened within a segment of the adult population, Bauer and Davies continued.
“We are still left with the difficult question of how to apply the concepts of overdiagnosis in this scenario. Pediatric thyroid cancer has a 98% rate of survival, even for patients with pulmonary metastasis, so benefits of treatment should not be considered in regard to effects on disease-specific mortality,” they pointed out.
Ohtsuru gave a lecture on this topic at the 5th International Expert Symposium in Fukushima on Radiation and Health, entitled “Chernobyl+30, Fukushima+5: Lessons and Solutions for Fukushima’s Thyroid Question.” His full presentation can be downloaded here.
Association between screening-detected thyroid cancers, radiation exposure ‘unlikely’ in Fukushima children
Many thyroid cancers detected by ultrasound screening in Japanese children in the 5 years after the 2011 Fukushima Daiichi nuclear accident mirror many low-risk, sporadic cases of adult thyroid cancer and are most likely not associated with radiation exposure, according to findings published in JAMA Otolaryngology Head & Neck Surgery.
“Large-scale mass screening of young people using ultrasonography resulted in the diagnosis of a number of thyroid cancers, including potential overdiagnosis cases,” Akira Ohtsuru, MD, PhD, professor in the department of radiation health management at Fukushima Medical University, Japan, told Endocrine Today. “These findings indicate that ultrasonography screening can identify many detectable cancers from large pool of nonclinical and subclinical thyroid cancers among individuals of a relatively young age, in an age-dependent manner.”
The level of radiation exposure in Fukushima immediately after the great earthquake in eastern Japan on March 11, 2011, has been deemed to be much lower than the levels reported in Chernobyl immediately after the 1986 nuclear power station accident, Ohtsuru and colleagues wrote in the study background. However, the researchers noted that there was a divergence in estimations of the thyroid equivalent dose of radiation during the early phase after the accident, as there was little direct measurement of the individuals, whereas radiation-induced thyroid cancers have been rated as causing some of the greatest concern after the accident.
“Thus, health surveillance, including thyroid screening, has been thought to be necessary for both scientific and social reasons,” the researchers wrote.
In an observational study, Ohtsuru and colleagues analyzed data from 324,301 Fukushima residents aged 18 years or younger at the time of the nuclear accident. Researchers assessed the number of detected cases of thyroid cancer during first (fiscal years 2011-2013) and second (fiscal years 2014-2015) rounds of screening, with age groups stratified by 3-year intervals. Researchers compared results against an age-specific incidence of unscreened cancers form a national cancer registry.
Researchers found that, among 299,905 participants screened in the first round (50.5% boys and men; mean age at screening, 15 years), 116 were diagnosed with malignant or suspected thyroid cancer. Among 271,083 participants screened in the second round, (50.4% boys and men; mean age at screening, 13 years), 71 were diagnosed with malignant or suspected thyroid cancer, according to researchers. In both the first- and second-round examinations, mean age at diagnosis was 17 years; however, mean tumor diameter was larger in the first- vs. the second-round screenings (mean, 12.7 mm vs. 9.7).
Papillary thyroid cancer was the most common pathologic diagnosis, they wrote, at 149 of 152 cases (98%). The researchers also noted that the distribution pattern by age group at the time of the accident increased with older age in both screening rounds, with an interval between screenings of about 2.1 years. The number of detected thyroid cancer cases per 100,000 persons was estimated to be approximately 175 for those aged 18 years at the time of the accident in the first round of screening and 97 for those aged 18 years at the time of the accident during the second round of screening.
Researchers calculated that the estimated age-conditional incidence rate of cases per 100,000 person-years was 0.5 for those aged 15 to 17 years, 1 for those aged 18 to 20 years and 1.7 for those aged 21 to 22 years.
“Although a longer observation period is needed, this pattern by age at the time of the accident differs from that of the Chernobyl nuclear power station accident; for example, there was a higher frequency of cases of cancer at younger ages with a relatively short latent period after the Chernobyl nuclear power station accident,” the researchers wrote. “Thus, an association between the large number of thyroid cancers detected and radiation exposure is thought to be very unlikely, in addition to the very low doses of radiation in the Fukushima nuclear power station accident.”
Ohtsuru added that, to ensure the merit of early detection and prevent overdiagnosis via large-scale screening, development of a careful monitoring system is urgently needed based on the understanding of the natural history of thyroid cancer.
In commentary accompanying the study, Andrew J. Bauer, MD, medical director of the Pediatric Thyroid Center at Children’s Hospital of Philadelphia, and Louise Davies, MD, MS, research fellowship director of the VA Outcomes Group at the Veterans Affairs Medical Center in White River Junction, Vermont, wrote that researchers should not assume that every asymptomatically discovered case of pediatric thyroid cancer is a “triumph of early detection.”
“Going forward, research to better define which pediatric thyroid cancers are likely to progress, and a better understanding of the trajectory of the natural history of thyroid cancers detected in early life, is urgently needed,” Bauer and Davies wrote. “The extremely high prevalence of subclinical thyroid cancer shown by the Fukushima Survey, including many with lymph node metastases, suggests that we have much to learn about the natural history of lymph node metastases, but that we should not assume that every asymptomatically identified case of pediatric thyroid cancer is an instance of overdiagnosis.” – by Regina Schaffer
Akira Ohtsuru, MD, PhD, can be reached at Fukushima Medical University, Department of Radiation Health Management, 1 Hikarigaoka, Fukushima 960-1295, Japan; email: ohtsuru@fmu.ac.jp.
Disclosures: One of the authors reports he received grants from commercial sponsor JCR Pharmaceuticals Co. Bauer and Davies report receiving travel funds from the International Agency for Research on Cancer.
December 7, 2018
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Fukushima 2018 | Fukushima Children, Thyroid Cancers |
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FUKUSHIMA — Five more people in Fukushima Prefecture who were 18 and under at the time of the 2011 nuclear accident were diagnosed with thyroid cancer as of the end of September this year, a prefectural investigative commission announced at a Dec. 25 meeting.
Fukushima Prefecture established the commission to examine the health of residents after the March 2011 triple meltdown at the Fukushima No. 1 nuclear power plant. A total of 159 Fukushima prefectural residents who were aged 18 and under when the meltdowns occurred have now been diagnosed with thyroid cancer.
The commission stated on Dec. 25 that “it is difficult to think the cases are related to radiation exposure” from the disaster.
December 27, 2017
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Fukushima 2017 | Fukushima, Thyroid Cancers |
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Nearly 80 percent of respondents in a survey by a group supporting children diagnosed with thyroid cancer in the wake of the Fukushima nuclear disaster say they remain worried about the cancer, despite the prognosis for those who receive appropriate treatment being good.
The survey was conducted by the 3.11 Fund for Children with Thyroid Cancer, an independent, not-for-profit organization providing support for child patients of thyroid cancer and their families. It was sent in August to 67 households of people who were living in Fukushima Prefecture at the time of the outbreak of the disaster at the Fukushima No. 1 Nuclear Power Plant in March 2011 and whose medical expenses the fund has helped to cover. A total of 52 households responded — a response rate of about 78 percent. Twelve of the respondents had received treatment themselves, while seven were fathers and 33 were mothers of those who had been treated.
A total of 40 respondents, or 77 percent, said they remained worried. When asked specifically what they were worried about, 23 people said “a relapse,” nine each cited “metastasis” and “health status in general,” while five each said they were worried about “pregnancy and childbirth” and “finding a job and working.”
Among children, some worried about cancer testing being scaled back. A total of 28 respondents called for the status quo to be maintained, while another 17 respondents called for the testing system to be enhanced. None said it should be downsized.
“Excessive diagnosis” has been blamed in the past for the large number of thyroid cancer patients in the wake of the nuclear disaster, but when given space to write their own opinions, some respondents were supportive of testing from the perspective of early detection of cancer, saying, “It’s better than finding out too late,” and “If a person has cancer, they’ll feel better if it’s removed.”
The fund’s representative director, Hisako Sakiyama, commented, “There’s a need to listen to what the afflicted people and their families want, and to hear what problems they are facing.”
December 10, 2017
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Fukushima 2017 | Fukushima Children, Fukushima Radiation, Thyroid Cancers |
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Seven more young Fukushima Prefecture residents have been diagnosed with thyroid cancer, according to a prefectural government statement on Monday. All of the patients were 18 or younger at the time of the 2011 nuclear reactor meltdown.
This bumps the number of Fukushima residents diagnosed with thyroid cancer up to 152. Although many times higher than the national average, the thyroid cancer rates are “unlikely” to have been increased by the reactor accident, according to vice chair of Fukushima’s medical association Hokuto Hoshi.
“Those thyroid cases have been found because we conducted the survey, not because of the radiation,” concurred Akira Ohtsuru, a radiologist who examined many of the patients. “The survey has caused over-diagnosis.”
One of those suspected of having cancer is a 4-year-old boy who hadn’t even been conceived yet when his parents fled Fukushima.
The prefectural government has been conducting thyroid checkups on evacuees every year since 2013. The number of cases continuously rises every time they do so: five additional cases in 2014 and two additional ones in May 2015. This means more and more evacuees are metastasizing the illness.
Fukushima University researchers have also found that evacuees have markedly higher rates of diabetes, liver and heart disease and obesity than the national average.
A May 2017 study from the Norwegian Institute for Air Research found that the Fukushima nuclear disaster had spread additional radiation across the entire planet, with the same amount of radiation as a single x-ray hitting the average person.
That same month, Penn State Medical Center published a study linking the Three Mile Island nuclear disaster of 1979 to higher rates of thyroid cancer near the Pennsylvania reactor.
https://sputniknews.com/asia/201706071054381393-fukushima-evacuee-thyroid-cancer-epidemic/
June 7, 2017
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Fukushima 2017 | Fukushima, Thyroid Cancers |
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7 new thyroid cancers in Fukushima but don’t worry: Hokuto Hoshi, head of the panel and vice chair of the prefectural medical association, called it “unlikely” that radiation was responsible for the increase.
A boy undergoes a thyroid cancer test at a hospital. The Fukushima Prefectural Government said seven more residents who were aged 18 or under at the time of the 2011 nuclear disaster have been found to have thyroid cancer.
FUKUSHIMA – Seven more Fukushima Prefecture residents who were aged 18 or under at the time of the 2011 nuclear accident have been found to have thyroid cancer, the prefectural government said Monday.
The number of Fukushima residents suffering from thyroid cancer now totals 152, the prefectural government said in a meeting of an expert panel.
Hokuto Hoshi, head of the panel and vice chair of the prefectural medical association, called it “unlikely” that radiation was responsible for the increase.
The prefectural government has conducted three sets of thyroid checkups following the March 2011 triple meltdown at Tokyo Electric Power Company Holdings Inc.’s Fukushima No. 1 nuclear power plant. The checkups also covered people who evacuated to other prefectures.
The second round of checkups from 2014 confirmed five new sufferers, and a third round launched in May last year uncovered two more.
The panel decided to consider improving its counting method, as the cancer can be detected during regular medical examinations, not only the government checkups.
http://www.japantimes.co.jp/news/2017/06/06/national/seven-fukushima-residents-diagnosed-thyroid-cancer/#.WTaLVDQlFzA
June 6, 2017
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Hisako Sakiyama, a medical doctor and representative of the 3.11 Fund for Children With Thyroid Cancer, speaks to reporters in Tokyo, Friday, March 31, 2017. Sakiyama, who has sat on government panels to investigate the Fukushima disaster, says a child who was 4 at the time of the disaster , has been diagnosed with thyroid cancer and that case is missing from the official government records.
TOKYO (AP) — A child diagnosed with thyroid cancer after the Fukushima nuclear accident is missing from government checkup records, an aid group said Friday, raising questions about the thoroughness and transparency of the screenings.
Japanese authorities have said that among the 184 confirmed and suspected cases of thyroid cancer in Fukushima, no one was under age 5 at the time of the 2011 meltdowns. They’ve said that suggests the cases are not related to nuclear-plant radiation, as many were after the 1986 Chernobyl disaster.
The 3.11 Fund for Children With Thyroid Cancer, however, said Friday that one child who was 4 when the meltdowns occurred has been diagnosed with thyroid cancer. That case is not listed in data from Fukushima Medical University, which is overseeing thyroid-cancer screening and surgeries and had treated the child.
Hisako Sakiyama, a medical doctor and representative of the 3.11 Fund, which gives aid to families of children diagnosed with thyroid cancer, said that any missing case is “a major problem,” and raises the possibility that others may also be missing from the data.
The university has been carrying out ultrasound screenings of some 300,000 youngsters in Fukushima 18 and younger at the time of the nuclear accident. It has repeatedly said it stands behind its data but declined to comment on individual cases, citing privacy concerns.
Seisho Tanaka, a spokesman for the screenings, said those who may have had tested negative could have developed cancer afterward and sought medical treatment outside the screening process. He declined to comment further.
The officials have argued the Fukushima cases are popping up because of “a screening effect,” meaning the meticulous testing uncovered cases that would not be known otherwise.
Sakiyama, who has sat on a legislative panel investigating the Fukushima nuclear disaster, said the screening system was flawed. The child, a boy now 10, and one of the fund’s aid recipients, had surgery at Fukushima Medical University last year and is receiving treatment there, making it difficult to think the university could be unaware of the case, she added.
“It is very puzzling how they would not want to come forward with the case,” she said, adding of the Fukushima cases and radiation: “There is no reason to outright deny the link.”
The boy, who continues to receive treatment from the hospital, and his family have not spoken publicly.
Thyroid cancer is usually not fatal with proper treatment. It’s extremely rare among children and young adults under normal conditions, but since young people are not typically screened for it, it can go undetected for years.
Of the thousands of thyroid cancer cases that surfaced after Chernobyl, in the Ukraine and Belarus, about half or about 15 percent, depending on the study, were those under age 5 at the time of the accident.
Keith Baverstock, professor at the University of Eastern Finland and an expert on health and radiation, thinks it’s important Fukushima medical records be transparent.
Although it’s still difficult to reach a conclusion on a link with radiation, studying the cancers and how they developed can shed light on the question, he said recently in a Skype call.
http://www.sfgate.com/news/medical/article/Fukushima-4-year-old-missing-in-Japan-11040388.php
March 31, 2017
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Fukushima 2017 | Government Records, Thyroid Cancers, Transparency |
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Highlights:
- One more case of suspected thyroid cancer was diagnosed by cytology since the last report.
- No additional surgeries since the last report: the number of confirmed cancer cases remains at 145 (101 in the first round and 44 in the second round)
- Total number of confirmed/suspected thyroid cancer diagnosed (excluding a single case of benign tumor) is 184 (115 in the first round and 69 in the second round)
- The second round screening data is still not final (confirmatory examination still ongoing).
- Thyroid Examination Evaluation Subcommittee will be convened in May or June 2017 to evaluate the results of the second round screening.
On February 20, 2017, less than two months since the last report, the 26th Oversight Committee for Fukushima Health Management Survey convened in Fukushima City, Fukushima Prefecture. Among other information, the Oversight Committee released the latest results (as of December 31, 2016) of the second and third rounds of the Thyroid Ultrasound Examination (TUE). Official English translation of the results will be posted here. The narrative below presents basic facts of TUE and its current results in perspective, including information covered during the committee meeting and the subsequent press conference.
Overview
As of December 31, 2016, there is only 1 more case with cancer or suspicion of cancer from the second round, making a grand total of 184 (185 including the single case of post-surgically confirmed benign nodule) for the first and second round screening results combined. The number of surgically confirmed cancer cases, excluding the aforementioned case of benign nodule, did not change from the previous report (101 from the first round and 44 from the second round), and the remaining 38 (14 from the first round and 24 from the second round) continue to be under observation.
The second round screening (the first Full-Scale screening) was originally scheduled to be conducted from April 2014 through March 2016, and the primary examination (with the participation rate of 70.9% and the progress rate of 100.0%), is essentially complete. But the confirmatory examination (with the participation rate of 79.5% and the progress rate of 95.0%) is still ongoing.
The third round screening (the second Full-Scale Screening) began on May 1, 2016 and is scheduled to run through March 2018–the end of Fiscal Year 2018. As of December 31, 2016, 87,217 out of the survey population of 336,623 residents have participated in the ongoing primary examination at the participation rate of 25.9%. The confirmatory examination began on October 1, 2016, with the participation rate of 29.6% so far.
Full-Scale Screening (first and second)
To be conducted every 2 years until age 20 and every 5 years after age 20, the Full-Scale screening began with the second round screening (the first Full-Scale Screening) in April 2014, including those who were born in the first year after the accident. There are 381,282 eligible individuals born between April 2, 1992 and April 1, 2012. As of December 31, 2016, 270,489 actually participated in the primary examination.
The participation rate remained the same as 3 months earlier at 70.9% but lower than 81.7% from the first round screening. Results of the primary examination have been finalized in 270,468 participants, and 2,226 (increased by 4 since the last Oversight Committee meeting) turned out to require the confirmatory examination.
The confirmatory examination is still ongoing for the second round. Of 2,226 requiring the confirmatory examination, 1,770 have participated at the participation rate of 79.5% (increased from the previous 75.8% but still lower than 92.8% from the first round screening). So far 1,681 have received final results including 95 that underwent fine needle aspiration cytology (FNAC) which revealed 69 cases suspicious for cancer.
Confirmation of thyroid cancer requires pathological examination of the resected thyroid tissue obtained during surgery. There has been no additional surgical case since the last reporting. As of December 31, 2016, 44 underwent surgery and 43 were confirmed to have papillary thyroid cancer. One remaining case was confirmed to have “other thyroid cancer” according to the classification in the seventh revision of Japan’s unique thyroid cancer diagnostic guidelines. A specific diagnosis was not revealed, but it has been reported as a differentiated thyroid cancer that is not known to be related to radiation exposure and it is allegedly neither poorly differentiated thyroid cancer nor medullary cancer.
The third round screening or the second Full-Scale Screening has covered 87,217 or 25.9% of the survey population of 336,623. The primary examination results have been finalized in 71,083 or 81.5% of the participants, revealing 483 to require the confirmatory examination. Results of the confirmatory examination have been finalized in 64 of 143 (29.6%) that have been examined. FNAC was conducted in one person with a negative result: No cancer case has been diagnosed from the third round as of now.
Confusing issues
Conducted every 2 years up to age 20, the TUE transitions at age 25 to milestone screenings to be conducted every 5 years. Some residents are beginning to participate in the age 25 milestone screening, and if they have never participated in the TUE, their milestone screening results will be added to the second round screening results. Thus the number of the second round screening participants is expected to increase even though the screening period technically ended in March 2016.
However, the third round screening survey population excludes the age 25 milestone screening participants: their results will be tallied up separately.
Also in some cases, confirmatory examinations from the second and third rounds might be simultaneously ongoing, or there could be significant delays in conducting confirmatory examinations due to logistical issues such as the lack of manpower. A two-year screening period originally designed for subsequent rounds of the Full-Scale Screening is essentially spread over a longer time period, overlapping with the next round of screening. A precise interpretation of results from each round of screening might be nearly impossible.
A newly diagnosed case in the second round
In the second round, only 1 case was newly diagnosed by FNAC with suspicion of cancer. It is a female from Koriyama-City who was 17 years old at the time of the March 2011 disaster. Her first round screening result was A1.
Prior diagnostic status of the cases newly diagnosed with cancer in the second round
Of 69 total cases suspected or confirmed with cancer in the second round, 32 were A1, 31 were A2, and 5 were B in the first round. One remaining case never underwent the first round screening (no information such as age, sex or place or residence, is available regarding this case).
Thirty-two cases that were A1 in the first round, by definition, had no ultrasound findings of cysts or nodules, whereas 7 of 31 cases that were previously diagnosed as A2 had nodules with the remaining 24 being cysts. All 5 cases that were previously diagnosed as B were nodules, and at least 2 of them had undergone the confirmatory examination in the first round.
This means 56 (32 “A1” and 24 “A2 cysts”)of 69 cases had no nodules detected by ultrasound in the first round which could have developed into cancer. This is 81% of the second round cases suspected or confirmed with cancer. It has been speculated by some that these 56 cases were new onset since the first round, suggesting the cancer began to form in 2 to 3 years after the first round screening, conflicting with the common notion that thyroid cancer in general is slow growing.
Akira Ohtsuru, the head of the TUE, explained that even though some of the small nodules are very easy to detect by ultrasound, exceptions arise when 1) the border of the lesion is ambiguous, 2) the density of the lesion is so low that it blends into the normal tissue, or 3) the lesion resembles the normal tissue. Thus, it is not because the nodules newly formed since the first round screening, but because the nodules were simply not detected even though they were there, that cases which previously had no nodules are now being diagnosed with cancer. Ohtsuru said that when such previously undetected nodules become relatively large enough to become detectable by ultrasound, they might look as if they suddenly appeared. Ohtsuru added that nodules that have already been detected by ultrasound do not to appear to grow very rapidly in general.
This is a better, more legitimate explanation than the previous ones he offered that stated the nodules were present in the first round albeit invisible. However, 56 out of 69 cases seem like a lot to be explained by this.
An issue of the female to male ratio
The female to male ratio of cancer cases warrants a special attention. For thyroid cancer, the female to male ratio is nearly 1:1 in the very young, but it is known to increase with age and decrease with radiation exposure. (See below Slide 2 in this post for more information). In the second round, the female to male ratio has been ranging from 1.19:1 to 1.44:1 overall, but the FY2015 municipalities have consistently shown a higher number of males than females with the most recent female to male ratio of 0.7:1.
What Ohtsuru said about the the female to male ratio boils down to the following:
The female to male ratio for thyroid cancer is influenced by the reason for diagnosis and the age. When the confirmatory examination of the second round screening is completed, the data will be analyzed by adjusting for age and participation rates by sex. The female to male ratio in Japan’s cancer registry data, including all ages, is around 3:1, but it used to be bigger at 4:1 or 6:1 in the 1980’s and earlier. In Fukushima, the TUE was conducted in asymptomatic youth around puberty–a different condition than the cancer registry. Yet even in the cancer registry, the female to male ratio tends to be close to 1:1 up to the puberty. Autopsy data of occult thyroid cancer in individuals who died of causes other than thyroid cancer show the female to male ratio of 1:1 or smaller (more males) in adults. This fact indicates that thyroid cancer screening would yield the female to male ratio close to 1:1 even in adults. Thus, it is scientifically expected that thyroid cancer screening in general leads to a smaller female to male ratio.
He is claiming that thyroid cancer diagnosed by cancer screening before becoming symptomatic–as opposed to symptomatic thyroid cancer diagnosed clinically–is expected to show the female to male ratio near 1:1 or smaller, i.e., as many males are diagnosed as females, or more males are diagnosed than females.
To say the least, calling extrapolation from autopsy data to screening “scientific” seems a bit of a stretch. Furthermore, Ohtsuru’s claim does not add up scientifically. South Korea, where active screening increased the incidence of thyroid cancer, did not observe a smaller female to male ratio as shown in the table of thyroid cancer incidence by sex and age group compiled from Ahn et al. (2016). It is obvious the female incidence is much higher than the male incidence without actually calculating the ratio.
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Thyroid cancer incidence by sex and age group per 100,000
in the 16 administrative regions in Korea
Compiled from Supplementary Tables 2 & 3 in Ahn et al. (2016) Thyroid Cancer Screening in South Korea Increases Detection of Papillary Cancers with No Impact on Other Subtypes or Thyroid Cancer Mortality (link)
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Furthermore, Ohtsuru’s claim that the female to male ratio tends to be close to 1:1 up to the puberty in the cancer registry is not corroborated by the actual data. The table below was compiled from the National estimates of cancer incidence based on cancer registries. The number of thyroid cancer cases for each sex was listed side-by-side for each year and age group. Then a total from 2000 to 2012 was tallied for each sex and age group to obtain the female to male ratio, because the number of cases varies from year to year. Even without knowing exactly which age range Ohtsuru meant by “up to the puberty,” it is clear that the female to male ratio is not at all close to 1:1.
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The number of thyroid cancer cases by sex and age group from 2000 to 2012
Compiled from the National estimates of cancer incidence based on cancer registries in Japan (link)
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According to this study, the female to male ratio peaks at puberty and declines with age, as excerpted below:
The increased F:M ratio in thyroid cancer incidence does not remain static with age. Female predominance peaks at puberty. […] This pattern occurs as the thyroid cancer incidence begins to increase at an earlier age in females than in males, leading to a rise in the F:M ratio. The ratio starts to decline as the male incidence rate begins to increase and, concurrently, the rate of increase in female incidence rate slows down. The steady decrease in F:M ratio with age continues, and the peak male rate does not occur until between 65 and 69 years of age, compared with the earlier peak female rate between 45 and 49 years of age, just before the mean age of menopause at 50 years.
An issue of the participation rate
The primary examination participation rate of 70.9% in the second round screening is lower than 81.7% in the first round. Most notable is the participation rate of the oldest age group: 52.7% for ages 16-18 (age at exposure) in the first round plummeted to 25.7% for ages 18-22 (age at examination) in the second round. It is 6.6% for ages 18-24 (age at examination) for the ongoing third round so far.
Younger age groups in school have maintained pretty high participation rates thanks to the school-based screening. The older age group often leave the prefecture for college or jobs, and it becomes increasingly difficult to get them to participate, especially with their interests fading in their busy lives.
The status of the new third-party committee
The “international, third-party, neutral, scientific, up-to-date and evidence-based” expert committee proposed by Chairman Hokuto Hoshi at the last committee meeting is being discussed at the prefectural level in consultation with the central government. The prefectural official admitted that the plan was to establish an independent entity that will offer, from a neutral standpoint, latest knowledge of thyroid cancer needed by the Oversight Committee.
A committee member Tamami Umeda from the Ministry of Health, Labour and Welfare elaborated on her vision of the third-party committee as an entity to review and organize the latest clinical and epidemiological knowledge and studies. It would be separate from the Thyroid Examination Evaluation Subcommittee that is intended to evaluate and analyze the status of the TUE, including the evaluation of radiation effects. (Note: In reality, the Thyroid Examination Evaluation Subcommittee has been far from being effective in analyzing the TUE data due to lack of information released by Fukushima Medical University on the premise of protecting personal clinical data).
Explaining that international organizations frequently separate a scientific review process from discussions relating to policy making in order to maintain neutrality, Umeda said she thought a similar process might be useful for the Fukushima Health Management Survey. This comment drew questions from committee members as well as the press about the status of the Oversight Committee itself: Is it a policy-making body? Is it not scientific enough?
It would make more sense to invite experts to join the Thyroid Examination Evaluation Subcommittee to incorporate knowledge gained from the latest research on thyroid cancer. Why it has to be an “international” committee is unclear other than to say that it was recommended by the Organizing Committee of 5th International Expert Symposium in Fukushima on Radiation and Health, including Shunichi Yamashita. A former chair to the Oversight Committee, Yamashita resigned from the position in March 2013 amid controversies surrounding “secret meetings.” Although no longer involved with the Oversight Committee, he has maintained ties with the Survey as Founding Senior Director of the Radiation Medical Science Center for the Fukushima Health Management Survey, the Office of International Cooperation for the Survey.
http://fukushimavoice-eng2.blogspot.fr/2017/02/fukushima-thyroid-examination-february.html
February 25, 2017
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Fukushima 2017 | Fukushima Radiation, Thyroid Cancers |
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FUKUSHIMA — Ten more people were diagnosed with thyroid cancer as of late September this year in the second round of a health survey of Fukushima Prefecture residents, which began in April 2014, a committee overseeing the survey disclosed on Dec. 27.
The number of people confirmed to have cancer during the second round of the survey stands at 44, while the overall figure including cases detected in the first round stands at 145.
The first round of checks — covering people aged 18 or under who were living in the prefecture at the time of the outbreak of the nuclear disaster at the Fukushima No. 1 Nuclear Power Plant — began in 2011. The second round covers about 380,000 people, including children who were born in the year following the outbreak of the disaster. The survey’s third round began in May this year.
Some have pointed to the danger of “excessive diagnoses” during health checks in which doctors find cases of cancer that do not require surgery, which could place a physical and mental burden on patients. There have accordingly been calls for the Fukushima Prefectural Government to scale down the scope of its health survey.
During a meeting of the oversight committee in Fukushima on Dec. 27, Hokuto Hoshi, deputy head of the Fukushima Medical Association, requested that the prefectural government set up a third-party organization to independently gather scientific knowledge on thyroid cancer. “Scientific discussion should be conducted independently,” he said.
http://mainichi.jp/english/articles/20161228/p2a/00m/0na/008000c
December 28, 2016
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Fukushima 2016 | Fukushima, Thyroid Cancers |
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A private fund in Japan has begun providing financial assistance for young people diagnosed with thyroid cancer after the 2011 Fukushima nuclear accident.
The 3.11 Fund for Children with Thyroid Cancer offers a lump sum of 100,000 yen, or 850 dollars, to help pay for treatment for patients up to the age of 25. The first payments were made to 35 people on Monday.
The fund’s name refers to March 11th, 2011, when a massive earthquake hit northeastern Japan, triggering tsunami that crippled a nuclear plant in Fukushima Prefecture.
People in Fukushima and 14 other prefectures in eastern Japan are eligible to apply.
Fund officials say that 9 of the 35 recipients are not residents of Fukushima Prefecture. They say that in at least one case, the cancer had spread to the lungs when the diagnosis was made.
They are soliciting applications for the assistance as well as donations.
An official says the fund hopes to offer support to as many people as possible, adding that the cost of treatment weighs heavily on some families.
https://www3.nhk.or.jp/nhkworld/en/news/20161228_04/
December 28, 2016
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Fukushima 2016 | Fukushima, Fund for Children with Tyroid Cancer, Thyroid Cancers |
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A member of a fund that helps children with thyroid cancer explains the prefectures to be covered by its offer to defray medical costs, at an event in Chiyoda Ward, Tokyo, on Monday.
Thyroid cancer fund to defray costs for young patients in Fukushima, 14 other prefectures
A fund supporting children with thyroid cancer said Monday it will pay part of the medical costs for young patients in Fukushima Prefecture and elsewhere in Japan.
The fund, called 3.11 Children’s Fund for Thyroid Cancer, will offer up to ¥200,000 to each patient 25 and under in 15 prefectures mainly in northeastern and eastern Japan, including Tokyo.
The regions were selected in accordance with various atmospheric dispersion models for radioactive iodine spread during the Fukushima nuclear crisis in 2011.
The fund will accept applications between December and March. After review, it will provide ¥100,000 for each case and additional ¥100,000 for relatively serious patients. A second round of applications will be accepted again from April.
The fund was initially promoted by politicians including former Prime Ministers Junichiro Koizumi and Morihiro Hosokawa, and supported by celebrities such as actress Sayuri Yoshinaga. It has received ¥20 million in donations from the public since September.
Some Japanese researchers published a report attributing most of the thyroid cancer cases found among children and adolescents after the disaster began to radiation spewed by the triple core meltdown at the tsunami-swamped Fukushima No. 1 power plant.
http://www.japantimes.co.jp/news/2016/11/28/national/thyroid-cancer-fund-defray-costs-young-patients-fukushima-14-prefectures/#.WDz7Dlzia-c
Private fund to help young thyroid cancer patients
A Japanese private foundation will offer financial aid to young people who have been diagnosed with thyroid cancer since the accident at the Fukushima Daiichi nuclear power plant.
The foundation said on Monday it will provide a lump sum of 100,000 yen, or about 900 dollars, starting next month.
People aged 25 years old and younger who have been diagnosed with thyroid cancer, including suspected cases, are eligible for the aid. They should be residents of Fukushima or one of the 14 other prefectures in eastern Japan.
The foundation says it has raised about 20 million yen in public donations to help them.
Fukushima Prefecture has been conducting medical checkups for about 380,000 children aged 18 or younger after the 2011 accident. 175 have been diagnosed with thyroid cancer or are suspected cases.
The foundation’s representative, Hisako Sakiyama, says these young people will have to live with the risk of cancer for many years. She says the foundation wants to provide psychological support as well.
Applications for the financial aid will be accepted through March next year. http://www3.nhk.or.jp/nhkworld/en/news/20161128_17/
November 29, 2016
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Fukushima 2016 | Fund, Thyroid Cancers |
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Of course this news was not released in the Japanese national main media nor in the Fukushima local media, it was only released in the Hokkaido Shimbun, a local media from the northern island Hokkaido.
Dr. Kazuo Shimizu
Dr. Kazuo Shimizu, Chairman of the Thyroid Examination Assessment Subcommittee and member of the Oversight Committee for the Fukushima Health Management Survey, a thyroid surgeon and Honorary Director at Kanaji Hospital, and Professor Emeritus at Nippon Medical School, and former chair of the board of the Japanese Society of Thyroid Surgery, submitted his resignation as Chairman of the Thyroid Examination Assessment Subcommittee.
As Chairman of the Thyroid Examination Assessment Subcommittee, he does not personally agree with the interim report conclusion that “it is unlikely that the effects of radiation” caused the high incidence of thyroid cancer found in the Fukushima Prefecture. Not agreeing with the drawn conclusions of the interim report and as Chairman not free to have a personal opinion, nor to express it, he decided to resign.
Dr. Kazuo Shimizu is a doctor, a leading authority in endoscopic surgery of the thyroid gland. Within the Fukushima population, 380,000 children below 18 years old at the time of the Fukushima Daiichi nuclear plant accident in March 2011 have been examined. 174 people have been so far diagnosed with thyroid cancer or suspected thyroid cancer.
Dr. Kazuo Shimizu says that such high incidence of thyroid cancer, from his long clinical experience, is unnatural. That frequency is a fact, which should not be explained, nor discarded by just the “It is unlikely that the effects of radiation.” caused that high incidence conclusion.
In the former Soviet Union after the 1986 Chernobyl nuclear accident, thyroid cancer was frequent in children due the released iodine-131.
http://headlines.yahoo.co.jp/hl?a=20161021-00010003-doshin-soci
However, it is not that surprising. When Oshidori Mako interviewing Dr. Kazuo Shimizu in May 2015 asked « Is it really overdiagnosis that is going on? », Dr. Kazuo Shimizu answered :“I am not in a position to be able to say, ‘It is not due to overdiagnosis.’ As chair of the Subcommittee, I cannot validate opinions of either side. It is hard for me. I would have been able to voice my opinions more clearly if I hadn’t been elected chair of the Subcommittee.”
http://fukushimavoice-eng2.blogspot.fr/2015/08/oshidori-mako-interviews-experts.html
October 23, 2016
Posted by dunrenard |
Fukushima 2016 | Fukushima continuing, Iodine-131, Lies & Cover-up, radiation, Thyroid Cancers |
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On September 26-27, 2016, the “5th International Expert Symposium in Fukushima on Radiation and Health: Chernobyl+30, Fukushima+5: Lessons and Solutions for Fukushima’s Thyroid Question” was held in Fukushima City. The symposium was organized by the Nippon Foundation, co-organized by Fukushima Medical University, Nagasaki University, and Hiroshima University, and supported by Fukushima Prefecture, Japan Medical Association, Japan Nursing Association, and Japan Pharmaceutical Association. Program PDF can be viewed here. Information on previous symposia can be found on the following web pages: 1st symposium, 2nd symposium, 3rd symposium, and 4th symposium.
The program featured the usual suspects from the pro-nuclear camp as some of the presenters who informed the audience that “Fukushima is different from Chernobyl” and emphasized the risk of overdiagnosis from cancer screening. This post focuses on clinical information for the surgical cases presented by Shinichi Suzuki, the thyroid surgeon at Fukushima Medical University in charge of the Thyroid Ultrasound Examination.
The last time Suzuki released such information was on August 31, 2015, and it was given in a narrative form on one sheet of paper (can be found here and translated here). This time it was given as a series of PowerPoint slides with more details than ever. Screenshots of some of the slides are shown below, accompanied by narrative explanations to put the information in context. Please note that this is neither the actual transcript of his presentation nor inclusive of all the slides shown during the presentation.
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“Childhood and Adolescent Thyroid Cancer after the Fukushima NPP Accident” by Professor Shinichi Suzuki, Fukushima Medical University (starts around 1:45:25 in the video embedded below, with Japanese interpretation).
http://www.ustream.tv/recorded/91672512
Note: Suzuki used the Thyroid Examination results released on June 6, 2016 with data as of March 31, 2016 during this presentation, although the new results as of June 30, 2016 were released on September 14, 2016.
Slide 1
This presentation covers 125 cases of thyroid cancer that underwent surgeries at Fukushima Medical University between August 2012 and March 2016. During this time period, 132 cases underwent surgeries, 126 at Fukushima Medical University and 6 at other medical facilities. At Fukushima Medical University, 1 case was post-operatively diagnosed as a benign thyroid nodule, leaving 125 cancer cases. (Note: The August 2015 report stated 7 cases underwent surgeries at facilities other than Fukushima Medical University, but now it is 6 cases. No explanation was given regarding this discrepancy).
As of March 31, 2016, 102 cases suspicious of cancer were operated from the first round (confirmed as 1 benign nodule and 101 cancer cases), while the second round yielded 30 cancer cases. Assuming the 6 cases operated at other medical facilities were from the first round, 125 cases presented here include 95 cases from the first round, leaving 30 cases to be accounted for by the second round. It is not clear how many of the first round and the second round cases were actually operated at Fukushima Medical University. 125 presented here may not include 30 cases from the second round. (Note: Previous sentence was crossed out and a new sentence added on October 11, 2016).
Slide 2
125 cases consisted of 44 males and 81 females, with the female-to-male ratio** of 1.8 to 1.
Age at the time of the accident (i.e. age at exposure) ranged from 5 to 18 years, with an average age of 14.8 ± 2.7 years. Age at diagnosis ranged from 9 to 23, with an average age of 17.8 ± 3.1 years.
Location of tumor was ipsilateral (i.e. one-sided) in 121 cases (96.8%) and bilateral (i.e. on both sides) in 4 cases. In 121 ipsilateral cases, 67 were located in the right lobe, 53 in the left lobe, and 1 in the isthmus which connects together the lower thirds of the right and left lobes.
**Thyroid cancer is known to occur more commonly in females. The female to male ratio tends to increase with age. For instance, the female to male ratio in the 2009 US study is 4.3:1 with 94.5% of cases ≥ age 10 [1] . In the 1995 study of the cancer registry data from 1963 to 1992 in England and Wales, the female to male ratio was 1.25:1 in ages 5-9 and 3.1:1 in ages 10-14 [2]. The female to male ratio is also known to decrease in the radiation exposed cases. In the 2008 study that compared thyroid cancer cases (exposed to radiation) in Belarus, Ukraine and Russia after the Chernobyl accident with unexposed cases in the same region as well as in UK and Japan, the female to male ratio was 4.2:1 overall, 2.4:1 in age <10, 5.2:1 in age ≥10 in the unexposed cases, whereas the female to male ratio was 1.5:1 overall, 1.3:1 in age <10, and 1.6:1 in age ≥10 in the exposed cases [3].
Slide 3
TNM classification is explained below. Japan has its own clinical guidelines on cancers, but the TNM classification is essentially the same with the exception of the “Ex” notation which refers to the degree of extension outside the thyroid capsule:
Ex1 means minimal extension (example: extension to sternothyroid muscle or perithyroid soft tissues) and is equivalent to T3.
Ex2 means further extension and is equivalent to T4.
Prefix “c” refers to “clinical” while “p” refers to “pathological.”
Pre-operative tumor size here refers to the largest diameter measured by ultrasound. It ranged from 5 mm to 53 mm with average of 14.0 ± 8.5 mm. (Note: The largest pre-op diameter was 45.0 mm for the first round and 35.6 mm for the second round. It is unclear where “53 mm” came from).
44 had tumor size ≤ 10 mm and limited to the thyroid.
57 had tumor size > 10 mm but ≤ 20 mm and limited to the thyroid.
12 had tumor size > 20 mm but ≤ 40 mm and limited to the thyroid.
12 had tumor size > 40 mm and limited to the thyroid, or any size tumor minimally extending outside the thyroid.
28 had metastases to the regional lymph node.
5 had lymph node metastases near the thyroid, within the central compartment of the neck.
23 had lymph node metastases to further areas of the neck.
3 had distant metastases to the lungs. This is the first time that any clinical details of the distant metastasis cases are given.
1) Male. Age at exposure 16, age at surgery 19.
Pre-operative: cT3 cN1a cM1. Tumor size > 40 mm and limited to thyroid or any size with minimal extension outside the thyroid. Metastasis to lymph nodes in the central compartment of the neck. Distant metastasis.
Post-operative: pT3 pEx1 pN1a pM1. Tumor size > 40 mm and limited to thyroid or any size with minimal extension outside the thyroid. Minimal extension outside the thyroid. Metastasis to lymph nodes within the central compartment of the neck. Distant metastasis.
2) Male. Age at exposure 16, age at surgery 18.
Pre-operative: cT3 cN1b cM1. Tumor size > 40 mm and limited to thyroid or any size with minimal extension outside the thyroid. Metastasis to the neck lymph nodes outside the central compartment. Distant metastasis.
Post-operative: pT2 pEx0 pN1b pM1. Tumor size > 20 mm but ≤ 40 mm and limited to the thyroid. No extension outside the thyroid. Metastasis to the neck lymph nodes outside the central compartment. Distant metastasis.
3) Female. Age at exposure 10, age at surgery 13.
Pre-operative: cT1b cN1b cM1. Tumor size > 1 cm but ≤ 2 cm, limited to the thyroid. Metastasis to the neck lymph nodes outside the central compartment. Distant metastasis.
Post-operative: pT3 pEx1 pN1b pM1. Tumor size > 40 mm and limited to thyroid or any size with minimal extension outside the thyroid. Minimal extension. Metastasis to the neck lymph nodes outside the central compartment. Distant metastasis.
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TNM classification for differentiated thyroid cancer from the American Cancer Society website.
Primary tumor (T)
T indicates the size of the primary tumor and whether it has grown into the nearby area.
T1a: Tumor ≤ 1 cm, limited to the thyroid
T1b: Tumor > 1 cm but ≤ 2 cm in greatest dimension, limited to the thyroid
T2: Tumor size > 2 cm but ≤ 4 cm, limited to the thyroid
T3: Tumor size >4 cm, limited to the thyroid or any tumor with minimal extrathyroidal extension (eg, extension to sternothyroid muscle or perithyroid soft tissues)
T4a: The tumor is any size and has grown extensively beyond the thyroid gland into nearby tissues of the neck, such as the larynx (voice box), trachea (windpipe), esophagus (tube connecting the throat to the stomach), or the nerve to the larynx. This is also called moderately advanced disease.
T4b: The tumor is any size and has grown either back toward the spine or into nearby large blood vessels. This is also called very advanced disease.
Regional lymph nodes (N)
Regional lymph nodes are the central compartment, lateral cervical, and upper mediastinal lymph nodes:
N0: No regional lymph node metastasis
N1: Regional lymph node metastasis
N1a: Metastases to level VI (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes)
N1b: Metastases to unilateral, bilateral, or contralateral cervical (levels I, II, III, IV, or V) or retropharyngeal or superior mediastinal lymph nodes (level VII)
Distant metastasis (M)
M0: No distant metastasis is found
M1: Distant metastasis is present
*****
Slide 4
This slide is similar to Slide 3, except it describes why surgeries were conducted in 44 “cT1a cN0 cM0” cases with tumor ≤ 10 mm without any pre-operative clinical evidence of lymph node or distant metastases. (Surgery for thyroid “microcarcinoma,” i.e. cancer ≤ 10 mm, is controversial in adults).
11 of 44 cases underwent surgeries despite the recommendation of non-surgical, observational follow-ups. Remaining 33 cases had suspicion for one or more of the following conditions:
20 cases: Ex1 or Ex2 (extension beyond the thyroid capsule)
3 cases: N1a (metastases to lymph nodes within the central compartment of the neck)
10 cases: Invasion of the recurrent laryngeal nerve
7 cases: invasion of the trachea
1 case: Graves disease
1 case: Ground-glass opacity (GGO) of the lungs
Slide 5
11 underwent total thyroidectomy where both right and left lobes of the thyroid were removed. Skin incision was limited to 4-5 cm.
114 had hemi-thyroidectomy where one lobe of the thyroid was removed. Skin incision was limited to 3cm.
All cases underwent the central lymph node dissection. 24 cases also had dissection of the lateral neck lymph nodes.
Japan’s clinical guidelines use a slightly different classification system of the regional lymph node levels (described at the end). Furthermore, “D classification” or “D number” is used to describe the extent of the lymph node dissection, which apparently corresponds to the selective neck dissection (SND) defined by the American Head and Neck Society and the American Academy of Otolaryngology-Head and Neck Surgery [
4]. The equivalent SND notation is shown when possible for easier understanding.
D0: No dissection, or the degree of dissection not reaching D1.
D1: Dissection of the central compartment lymph nodes (prelaryngeal, pretracheal, paratracheal and prethyroidal). Can be unilateral of bilateral. Equivalent to SND (VI).
D2a: D1 plus dissection of middle jugular and lower jugular nodes. Equivalent to SND (III, IV, VI).
D2b: D2a plus dissection of upper jugular and posterior triangle nodes. Equivalent to SND (II-V, VI).
D3a: Bilateral D2a. Equivalent to bilateral SND (III, IV, VI)
D3b: Bilateral D2b, or D2a plus contralateral D2b.
D3c: D2 or D3 plus dissection of superior mediastinal nodes.
Slide 6
This slide shows what was found during the surgery and subsequent pathological examination of the excised tissues and lymph nodes.
Shown here side by side with the pre-operative findings, it becomes clear that fewer cases are limited to thyroid and ≤ 20 mm, while more cases turned out to have minimal extension and the regional lymph node involvement.
Notable is the number and percentage of cases confirmed to have minimal extension outside the thyroid capsule, pEx1. This number, 49 (40%), is the same as pT3, suggesting pT3 in this group denotes any size tumor with minimal extension outside the thyroid capsule.
Even more notable is the number of regional lymph node metastases. 5 cases of cN1a turned out to be 76 cases of pN1a. Overall, 97 (77.6%) of 125 had regional lymph node metastasis.
Slide 7
This slide shows the post-operative findings of 44 “cT1a cN0 cM0” cases with tumor smaller than 10 mm without any pre-operative clinical evidence of lymph node or distant metastases described in Slide 4.
Of 11 cases that underwent surgery against the recommendation of non-surgical, observational follow-ups, 2 cases turned out to be pT1a pN0 pEx0, meaning the tumor was ≤ 10 mm without any regional lymph node involvement or extension beyond the thyroid capsule.
Of remaining 33 cases that had indications for surgery as described in Slide 4, 3 cases turned out to be pT1a pN0 pEx0.
Overall, 5 of 44 cases with tumor size ≤ 10 mm turned out to have no lymph node involvement or extension beyond the thyroid capsule, suggesting these 5 cases might not have actually needed surgery at the time. But this is in hindsight, and it should be remembered 33 cases originally did have clear surgical indications. (Curiously, the previous report from August 2015 states this number was “8.” No explanation was given by Suzuki as to the discrepancy. However, his
admittance of “a few percent of recurrence” might allow for speculation that 3 of 8 cases recurred and no longer was classified “pT1a pNO pEx0.” It should be noted this has
not been confirmed by Suzuki. It is expected he might discuss clinical details such as the recurrence rate during his presentation on the Thyroid Examination at the Annual Meeting of the Japan Thyroid Association on November 13-15, 2016, in Tokyo.
Slide 8
This slide shows the types of thyroid cancer found in 125 cases. 121 had papillary thyroid cancer (PTC), 3 had poorly differentiated thyroid cancer, and 1 had “other” thyroid cancer.
It should be noted that 2 of 3 cases of poorly differentiated thyroid cancer
has since been reclassified as papillary thyroid cancer with unspecified subtypes in accordance with the revision of the thyroid cancer clinical guidelines (see
this post for more information).
121 cases of papillary thyroid cancer showed 4 subtypes/variants:
110 cases of classical type
4 cases of follicular variant*
3 cases of diffuse sclerosing variant
4 cases of cribriform-morular variant**
A special notation was made by Suzuki that
no solid variant of PTC–the most common subtype in Chernobyl–was seen. This is one of the claims repeated by the officials to emphasize the Fukushima cancer cases are unlike those in Chernobyl, i.e. unlikely to be due to the radiation effects. However, solid variant PTC is
not exclusive to radiation-induced thyroid cancer, and a high frequency of solid variant PTC observed in Chernobyl might be due to the young age of the early cases [
5,
6,
7]. Moreover, in
one study, solid variant was not seen in Japanese childhood PTC [
8].
*Recently, encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) was reclassified as “noninvasive follicular thyroid neoplasm with papillary-like nuclear features” (NIFTP) [
9]. However, cases of the follicular variant of papillary thyroid cancer found here are not assumed to be EFVPTC since they were never reclassified as non-cancer. This subject never came up during the Oversight Committee meetings.
**Cribriform-morular variant is usually associated with familial adenomatosis polyposis.
Slide 9
This slide shows algorithms for diagnosis and treatment of papillary thyroid cancer according to the Japanese clinical guidelines.
Slide 10
This slide shows a comparison of surgical methods between Belarus and Fukushima. Most cases in Fukushima underwent hemithyroidectomy or lobectomy, whereas total thyroidectomy was the most common surgical method in Belarus.
Suzuki mentioned that extra care has been taken to reduce complications from surgeries, and hemithyroidectomy was employed when possible to decrease the lifetime need for thyroid hormone supplementation. Also, this article by Japan’s top thyroid surgeons states, “At present, Western countries adopted almost routine total thyroidectomy with radioactive iodine (RAI) ablation, while limited thyroidectomy with extensive prophylactic lymph node dissection has traditionally been performed for most patients in Japan.(…) In Japan, however, limited thyroidectomy such as subtotal thyroidectomy and lobectomy with isthmectomy has been traditionally adopted as the standard. This is partially because the capacity to perform RAI therapy is limited due to legal restrictions, and RAI therapy is not considered cost effective by the healthcare system in Japan. [10]”
Slide 11
This slide shows the genetic mutation profile in different study groups. 63.2% of 52 cases from Fukushima was shown to have BRAF mutation. In the 2015 study by Mitsutake et al.[11] shown in the green box, 43 (63.2%) of 68 cases are shown to be positive for BRAF V600E point mutation. The same study also shows 10.3% was positive for RET/PTC rearrangements (6 cases of RET/PTC1 and 1 case of RET/PTC3) and 4 cases (5.9%) had ETV6/NTRK3 rearrangement. (It’s unclear where “n=52” and 8.8% of TRK fusion came from for the Fukushima column, as the Mitsutake study has n=68 and did not test for TRK fusion. It’s also unclear where the Japanese adult data came from. Literature search revealed the BRAF frequency in PTC of Japanese adults varied in a wide range: 28.8% [12], 38.2% [13], 38.4% [14] , 53% [15], and 82.1% [16]).
The official stance is that the genetic alterations observed in Fukushima cases are similar to what is seen in typical adult papillary thyroid cancer and “probably reflects genetic status of all sporadic and latent thyroid carcinomas in the young Japanese population [11].” In other words, the official assert that the genetic profile appears consistent with the official claim that screening is diagnosing spontaneous and latent cancers which might not have been detected without screening.
However, literature varies in regards to how the genetic mutations are associated with radiation exposure, age, and iodine status. RET/PTC rearrangements, frequently seen in Chernobyl, are associated with both radiation-induced and spontaneous thyroid cancer [17], more common at younger age and in iodine deficient areas [18]. BRAF mutation is known to be seen more frequently in older age, but recent studies showed BRAF V600E was present in 36.8% (median age 13.7 years) [19] and 63% (median age 18.6 years) [20] of pediatric papillary thyroid carcinoma. BRAF mutation were associated with high iodine intake in China [21], while no difference in BRAF V600E frequency was found between iodine-rich and iodine-deficient countries recently [16].
Slide 12
This slide shows a graph with age distribution of thyroid cancer patients in Ukraine and Fukushima in different post-accident time periods, compiled by superimposing 2 graphs from Letter to the Editor of Thyroid [21]. Blue bars are for 1986-1990 in Ukraine (first 4 years after the Chernobyl accident) and red bars are for 2011-2013 in Fukushima (first 3 years after the Fukushima accident), both time periods representing “latency” for radiation-induced thyroid cancer in children. Orange bars are for 1990-1993 in Ukraine–after the latency period–showing a large increase in thyroid cancer cases in Ukrainian residents who were 18 or younger when the accident happened. Increased number of cases in those who were age 5 or younger set this time period apart. The year 1990 is also when large-scale screening programs began, initiated by international organizations [22].
The age distribution is “strikingly similar” between the first 4 post-accident years in Ukraine (blue bars) and the first 3 years in Fukushima (red bars), as acknowledged by the letter. However, the letter is inconsistent in claiming “if thyroid cancers in Fukushima were due to radiation, more cases in exposed preschool-age children would have been expected” and defining the first 4 years as “latency.” This illogical claim is also seen in a slightly different format as a comparison between different post-accident periods [23].
Concluding summary
The official stance is that thyroid cancer cases detected after the Fukushima accident are more likely due to the screening effect, meaning the screening discovered spontaneous and latent cancers that were not causing any symptoms and would not become clinically significant until much later if it weren’t for the screening. However, clinical details show that most cases were not so innocuous: extending outside thyroid gland; metastasizing to cervical lymph nodes or even to the lungs; or invading vital structures such as the trachea and the recurrent laryngeal nerve. A few cases may represent overdiagnosis/overtreatment, but for the vast majority of the cases, surgeries were clearly indicated medically. It’s even questionable if some of the cases were truly asymptomatic. Detailed, specific questions regarding potential symptoms were not asked, at least in the information sheet submitted with the consent form. Whether further questioning about the symptoms occurred during the confirmatory examination is unknown. More transparency is warranted.
Female to male ratio seems higher than expected considering the average age of the patients. Histological type and genetic alterations commonly seen in Chernobyl may not be observed in Fukushima cases, but this could be due to variations in age, iodine status, or ethnic background between the two groups.
The phrase, “Fukushima is not Chernobyl” was frequently repeated during the symposium. Indeed, it is time that Fukushima data be given a fresh look by unbiased experts who can analyze it as is, rather than endless comparisons with Chernobyl to prematurely deny radiation effects.
*****
Classification of cervical lymph nodes by the Japanese clinical guidelines
I: Prelaryngeal nodes: LN anterior to the thyroid cartilage and the cricoid cartilage
II: Pretracheal nodes: LN anterior to trachea, dissectible posteriorly from the inferior border of thyroid
III: Paratracheal nodes: LN lateral to trachea, extending inferiorly to where it is dissectible from the neck and superiorly where recurrent laryngeal nerve enters trachea.
IV: Prethyroid nodes: LN adjacent to anterior and lateral parts of thyroid. Laterally includes LN attached to thyroid when middle thyroid artery is ligated and cut. (Equivalent to the AJCC Level IV: lower jugular nodes)
(I, II, III and IV are equivalent to the AJCC Level VI: anterior compartment LN)
V: Superior internal jugular nodes: LN along internal jugular vein but superior to the inferior border of cricoid cartilage. This is further subdivided into superior and inferior at the bifurcation of common carotid artery
Va LN: inferior to the bifurcation of common carotid artery (equivalent to the AJCC Level II: upper jugular nodes)
Vb LN: superior to the bifurcation of common carotid artery (equivalent to the AJCC Level III: middle jugular nodes)
VI: Inferior internal jugular nodes: LN along internal jugular vein, inferior to the inferior border of cricoid cartilage. Includes LN in supraclavicular fossa.
VII: Posterior triangle nodes: LN located in posterior triangle bordered by anterior border of sternocleidomastoid muscle, posterior border of trapezius muscle, and omohyoid muscle.
VIII: Submandibular nodes: LN in the submandibular triangle.
IX: Submittal nodes: LN in the submental triangle.
(VIII and IX are equivalent to the AJCC Level I)
X: Superficial cervical nodes: LN superficial to superficial layer of the deep cervical fascia enclosing sternohyoid and sternocleidomastoid muscles.
XI: Superior mediastinal nodes: LN unresectable by neck dissection
(Equivalent to the AJCC Level VII: superior mediastinal nodes)
References
[1] Hogan AR, Zhuge Y, Perez EA, Koniaris LG, Lew JI, Sola JE. Pediatric thyroid carcinoma: incidence and outcomes in 1753 patients. J Surg Res. 2009 Sep;156(1):167-72. doi: 10.1016/j.jss.2009.03.098.
[2] Harach HR, Williams ED. Childhood thyroid cancer in England and Wales. British Journal of Cancer. 1995;72(3):777-783.
[3] Williams ED, Abrosimov A, Bogdanova T, et al. Morphologic Characteristics of Chernobyl-Related Childhood Papillary Thyroid Carcinomas Are Independent of Radiation Exposure but Vary with Iodine Intake. Thyroid. 2008;18(8):847-852. doi:10.1089/thy.2008.0039.
[4] Robbins K, Clayman G, Levine PA, et al. Neck Dissection Classification Update: Revisions Proposed by the American Head and Neck Society and the American Academy of Otolaryngology–Head and Neck Surgery. Arch Otolaryngol Head Neck Surg. 2002;128(7):751-758. doi:10.1001/archotol.128.7.751.
[5] Ory C, Ugolin N, Schlumberger M, Hofman P, Chevillard S. Discriminating Gene Expression Signature of Radiation-Induced Thyroid Tumors after Either External Exposure or Internal Contamination. Genes. 2012;3(1):19-34. doi:10.3390/genes3010019.
[6] Tronko MD, Bogdanova TI, Komissarenko IV, Epstein OV, Oliynyk V, Kovalenko A, Likhtarev IA, Kairo I, Peters SB, and LiVolsi VA. Thyroid carcinoma in children and adolescents in Ukraine after the Chernobyl nuclear accident. Cancer. 1999;86:149–156. doi:10.1002/(SICI)1097-0142(19990701)86:1<149::AID-CNCR21>3.0.CO;2-A.
[7] LiVolsi, VA, et al. The Chernobyl Thyroid Cancer Experience: Pathology. Clinical Oncology. 23(4):261-267.
[8] Williams ED, Abrosimov A, Bogdanova T, et al. Morphologic Characteristics of Chernobyl-Related Childhood Papillary Thyroid Carcinomas Are Independent of Radiation Exposure but Vary with Iodine Intake. Thyroid. 2008;18(8):847-852. doi:10.1089/thy.2008.0039.
[9] Nikiforov YE, Seethala RR, Tallini G, et al. Nomenclature Revision for Encapsulated Follicular Variant of Papillary Thyroid Carcinoma: A Paradigm Shift to Reduce Overtreatment of Indolent Tumors. JAMA Oncol. 2016;2(8):1023-1029. doi:10.1001/jamaoncol.2016.0386.
[10] Ito Y. and Miyauchi A. Thyroidectomy and Lymph Node Dissection in Papillary Thyroid Carcinoma. Journal of Thyroid Research. 2011; Article ID 634170, 6 pages. doi:10.4061/2011/634170.
[11] Mitsutake N, Fukushima T, Matsuse M, et al. BRAFV600E mutation is highly prevalent in thyroid carcinomas in the young population in Fukushima: a different oncogenic profile from Chernobyl. Scientific Reports. 2015;5:16976. doi:10.1038/srep16976.
[12] Namba H, Nakashima M, Hayashi T, Hayashida N, Maeda S, Rogounovitch TI, Ohtsuru A, Saenko VA, Kanematsu T, and Yamashita S. Clinical Implication of Hot Spot BRAF Mutation, V599E, in Papillary Thyroid Cancers. The Journal of Clinical Endocrinology & Metabolism. 2003;88(9):4393-4397.
[13] Nasirden A, Saito T, Fukumura Y, et al. Virchows Arch (2016). doi:10.1007/s00428-016-2027-5.
[14] Ito Y, Yoshida H, Maruo R, et al. BRAF Mutation in Papillary Thyroid Carcinoma in a Japanese Population: Its Lack of Correlation with High-Risk Clinicopathological Features and Disease-Free Survival of Patients. Endocrine Journal. 2009;5(1):89-97.
[15] Fukushima T, Suzuki S, Mashiko M, et al. BRAF mutations in papillary carcinomas of the thyroid. Oncogene. 2003;22:6455–6457. doi:10.1038/sj.onc.1206739.
[16] Vuong HG, Kondo T, Oishi N, et al. Genetic alterations of differentiated thyroid carcinoma in iodine‐rich and iodine‐deficient countries. Cancer Medicine. 2016;5(8):1883-1889. doi:10.1002/cam4.781.
[17] Nikiforov YE, Rowland JM, Bove KE, Monforte-Munoz H, and Fagin JA. Distinct Pattern of ret Oncogene Rearrangements in Morphological Variants of Radiation-induced and Sporadic Thyroid Papillary Carcinomas in Children. Cancer Res. May 1997;57(9):1690-1694.
[18] Leeman-Neill RJ, Brenner AV, Little MP, Bogdanova TI, Hatch M, Zurnadzy LY, Mabuchi K, Tronko MD, and Nikiforov YE. RET/PTC and PAX8/PPARγ chromosomal rearrangements in post-Chernobyl thyroid cancer and their association with iodine-131 radiation dose and other characteristics. Cancer. 2013;119:1792–1799. doi:10.1002/cncr.27893.
[19] Givens DJ, Buchmann LO, Agarwal AM, Grimmer JF, and Hunt JP. BRAF V600E does not predict aggressive features of pediatric papillary thyroid carcinoma. The Laryngoscope. 2014;124:E389–E393. doi: 10.1002/lary.24668.
[20] Henke LE, Perkins SM, Pfeifer JD, Ma C, Chen Y, DeWees T, and Grigsby PW. BRAF V600E mutational status in pediatric thyroid cancer. Pediatr Blood Cancer. 2014;61:1168–1172. doi:10.1002/pbc.24935.
[21] Guan H, Ji M, Bao R, et al. Association of High Iodine Intake with the T1799A BRAF Mutation in Papillary Thyroid Cancer. The Journal of Clinical Endocrinology & Metabolism. 2009;94(5):1612-1617. doi:10.1210/jc.2008-2390.
[22] International Advisory Committee. The International Chernobyl Project. Assessment of radiological consequences and evaluation of protective measures.
Technical Report. Vienna: International Atomic Energy Agency; 1991.
[23] Takamura N, Orita M, Saenko V, Yamashita S, Nagataki S, and Demidchik Y. Radiation and risk of thyroid cancer: Fukushima and Chernobyl. The Lancet Diabetes & Endocrinology. 2016;4(8):647. doi:10.1016/S2213-8587(16)30112-7.
October 14, 2016
Posted by dunrenard |
Fukushima 2016 | Fukushima continuing, Thyroid Cancers |
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The high rate of thyroid cancer occuring in Fukushima is not caused by radiation. Or so the government would like everyone to believe!
Study draws a blank on thyroid cancer and 2011 nuclear disaster
Researchers have found no correlation between radiation exposure and the incidence rate of thyroid cancer among 300,000 children living in Fukushima Prefecture at the time of the 2011 nuclear disaster.
But the team at Fukushima Medical University, which carried out the study, cautioned that the health of local children should continue to be monitored to be more definitive.
“At the present stage, we have found no evidence pointing to any relationship between doses of external radiation resulting from the nuclear accident and the thyroid cancer rate,” said Tetsuya Ohira, a professor of epidemiology at the university. “But we need to continue to look into the situation.”
The study involves 300,476 children in Fukushima Prefecture who were aged 18 or younger when the Fukushima No. 1 nuclear power plant went into a triple meltdown in March 2011 after the Great East Japan Earthquake and tsunami.
The children underwent the first round of health checks between October 2011 and June 2015.
Of the total, 112 were tentatively diagnosed as having thyroid cancer.
There are two types of radiation exposure: external exposure in which a person is exposed to radiation in the atmosphere, and internal exposure in which a person is exposed through the intake of contaminated food, water and air.
For the study, municipalities in the prefecture were classified into three groups based on the estimate for residents’ external exposure. That data was obtained during a prefecture-wide health survey carried out after the disaster occurred.
The first group is a zone where people with an accumulative dose of 5 millisieverts or more represented 1 percent or more of the population there. The second group is a zone where people with an accumulative dose of up to 1 millisievert account for 99.9 percent or more of the population. The third group is a zone that falls into neither of the other two groups.
The scientists looked at the incidence rate for thyroid cancer in each group and concluded there is almost no difference among the groups.
The number of subjects diagnosed with thyroid cancer was 48 per 100,000 people in the first group, 41 in the second group and 36 in the third group.
The finding was similar to a separate survey in which researchers looked into the possible association among 130,000 or so children whose radiation exposure had been estimated.
Hokuto Hoshi, head of a health survey panel set up at the prefectural government after the nuclear disaster, said he will closely follow the results of future studies to offer a more conclusive finding.
“The outcome of the recent study provides one indication in making any overall judgment,” said Hoshi, who also serves as vice chairman of the Fukushima Medical Association. “The study is substantial and we are going to pay attention to the findings of further studies.”
http://www.asahi.com/ajw/articles/AJ201609100031.html
September 11, 2016
Posted by dunrenard |
Fukushima 2016 | Fukushima continuing, Lies & Cover-up, radiation, Thyroid Cancers |
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A group comprising medical and legal experts announced Friday it has launched a fund to provide financial support to children who were diagnosed with thyroid cancer after the 2011 nuclear meltdowns in Fukushima Prefecture.
The group, named 3/11 Children’s Fund for Thyroid Cancer, will start accepting donations from Sept. 20, aiming to raise at least ¥20 million. The amount could provide at least ¥50,000 each for 200 to 400 people, it said.
Donated funds will be used primarily to cover medical expenses for thyroid cancer patients in Fukushima and neighboring prefectures, it said. The group will announce more details in November on the criteria that will be used to determine who is eligible to receive the aid before it starts accepting applications.
“They are struggling to pay medical bills,” Hiroyuki Kawai, a lawyer and one of the founding members of the group, said at a news conference in Tokyo. “I don’t think ¥50,000 will be enough for them, but they are impoverished and are struggling, and even that amount will be of help.”
Currently, the medical expenses of children diagnosed with thyroid cancer in Fukushima Prefecture are covered by the prefectural government.
Patients, however, have to initially pay their medical expenses out of pocket until they start receiving refunds from the prefecture, placing great financial strain on many families, another member of the group said.
In addition to that, some parents often have to take leave from work to accompany their children during hospital visits, which also includes paying for travel expenses, they said.
According to the group, although medical treatment for thyroid cancer is covered by public health insurance, the patients still have to pay about ¥10,000 per examination and roughly ¥150,000 for surgical procedures. And if patients have to undergo endoscopic surgery, it would cost them an additional ¥300,000, it said.
Since October 2011, the Fukushima government has conducted thyroid screenings for some 380,000 children who were aged 18 or younger.
By the end of March, a total of 173 children were diagnosed with suspected thyroid cancer. Of those, 131 were confirmed to have the cancer after undergoing surgery.
A panel of experts under the prefectural government said in an interim report released in March that those thyroid cancer cases were unlikely to be radiation-induced.
The panel said the amount of radiation released was lower than in the 1986 Chernobyl accident, where more than 6,000 children were diagnosed with the cancer by 2005, and noted that no cancer was found among children aged under 5 at the time of the disaster who are more vulnerable to radiation exposure.
http://www.japantimes.co.jp/news/2016/09/09/national/fund-started-help-fukushima-thyroid-cancer-patients-cover-expenses/#.V9L7aTX8-M8
September 9, 2016
Posted by dunrenard |
Fukushima 2016 | Fukushima continuing, Fukushima Daiichi, Thyroid Cancers |
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