nuclear-news

New research on papillary thyroid cancer confirms the accepted science on the harmful effects of ionising radiation.

 

Our work provides a foundation for further investigation of radiation-induced cancer, particularly with respect to differences in risk as a function of both dose and age, and underscores the deleterious consequences of ionizing radiation exposure.

Radiation-related genomic profile of papillary thyroid cancer after the Chernobyl accident, Science Magazine, Lindsay M. Morton, Danielle M. Karyadi et al. 23 Apr 21,

Abstract

The 1986 Chernobyl nuclear power plant accident increased papillary thyroid cancer (PTC) incidence in surrounding regions, particularly for 131I-exposed children. We analyzed genomic, transcriptomic, and epigenomic characteristics of 440 PTCs from Ukraine (359 with estimated childhood 131I exposure and 81 unexposed children born after 1986). PTCs displayed radiation dose-dependent enrichment of fusion drivers, nearly all in the mitogen-activated protein kinase pathway, and increases in small deletions and simple/balanced structural variants that were clonal and bore hallmarks of non-homologous end-joining repair. Radiation-related genomic alterations were more pronounced for those younger at exposure. Transcriptomic and epigenomic features were strongly associated with driver events but not radiation dose. Our results point to DNA double-strand breaks as early carcinogenic events that subsequently enable PTC growth following environmental radiation exposure.

The accidental explosion in reactor 4 at the Chernobyl (Chornobyl in Ukrainian) nuclear power plant in April 1986 resulted in the exposure of millions of inhabitants of the surrounding areas of Ukraine, Belarus, and the Russian Federation to radioactive contaminants (1). Epidemiologic and clinical research in the ensuing decades has demonstrated increased risk of papillary thyroid carcinoma (PTC) with increasing thyroid gland exposure to radioactive iodine (131I) from fallout, which was deposited on pastures with grazing cows and ingested through milk and leafy greens, particularly during early childhood (2). Together with data from populations exposed to other types of radiation, compelling evidence indicates that PTC risk increases following childhood exposure to ionizing radiation, a recognized carcinogen (2–5)……….

The majority of individuals with PTC were female (n = 335, 76.1%), resided in the Kiev (Kyiv in Ukrainian) region at the time of the accident (n = 286, 65.0%), and were diagnosed during young adulthood (mean = 28.0 years, range: 10.0-45.6),,……..

The pronounced evidence of radiation-related damage that we observed for individuals exposed at younger ages is consistent with epidemiologic analyses that have identified higher thyroid cancer risks with radiation exposure at younger ages …………

our data are consistent with a linear dose-response for the key molecular characteristics associated with radiation dose in the range examined in our analysis (≤1 Gy), which aligns with the extensive radiobiological literature and other epidemiologic evidence regarding DNA damage and cancer risk following ionizing radiation exposure………….

Our work provides a foundation for further investigation of radiation-induced cancer, particularly with respect to differences in risk as a function of both dose and age, and underscores the deleterious consequences of ionizing radiation exposure.  https://science.sciencemag.org/content/early/2021/04/21/science.abg2538.full

April 24, 2021 - Posted by Christina Macpherson | radiation, Ukraine