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Surgery and ablation for 3-cm or smaller, node-negative breast tumors yielded a local recurrence rate of 1.4% over nearly 5 years of follow-up, Misti Wilson, MD, of the University of Arkansas for Medical Sciences in Little Rock, and colleagues found.

Cosmesis was “good” to “excellent” in 90% of these women treated without standard radiation, Wilson reported at a press briefing in conjunction with the American Society of Breast Surgeons meeting in Phoenix.

These results, albeit from an uncontrolled 73-patient study, put the strategy on par with partial breast irradiation, Wilson noted.

It “can replace radiation therapy in certain select patients with small tumors and clinically negative nodes,” she concluded.

Peter Beitsch, MD, of the Dallas Breast Center, who presented a separate registry study on accelerated partial breast irradiation at the same briefing showing it equal to whole breast irradiation for local control, agreed that radiofrequency ablation is looking like a competitor.

“That’s great,” he told reporters. “Whatever we can do to reduce treatment time for women is spectacular.”

Partial breast irradiation, or brachytherapy, takes 1 week compared with 7 for standard radiation therapy, he noted.

The radiofrequency ablation technique used in the study allows women to be finished with treatment before they’re discharged, explained V. Suzanne Klimberg, MD, principle investigator on the study done at the University of Arkansas for Medical Sciences where she serves as director of the breast cancer program.

A high proportion of women — up to 80% — don’t get their prescribed radiation therapy after surgery.

For some, especially in poor, rural areas like Arkansas, the logistics or cost of returning for radiotherapy puts it out of reach, Klimberg noted.

One advantage of radiofrequency ablation in that regard is its much lower cost compared with intraoperative radiation therapy, she added.

“This is a cheap way to do it, cheaper than any other way,” Klimberg said at the briefing.

For the 73 women in the study, the surgeon did a lumpectomy; then the radiofrequency ablation probe was placed in the tumor bed and heated to 100° C for 15 minutes to create a 1-cm ablation zone, thereby extending the margins. None had radiation.

Only 4% of the cohort required a second surgery because of grossly positive margins or residual calcifications of postoperative mammography (3 of 73). Among those with close or focally positive margins, 84% were spared re-excision (16 of 19).

After a median follow-up of 55 months, only one of the 73 patients had a local recurrence in the tumor bed.

Three had recurrences elsewhere in the ipsilateral breast, of which one was more than 5 cm from the original tumor site and another was a different type than the initial tumor (mucinous versus invasive ductal carcinoma).

Cosmesis scored in 40 patients according to standard criteria showed an “excellent” outcome in 45%, “good” in another 45%, and “fair” in the other 10%.

Five-year data are likely sufficient to show the impact of treatment, Beitsch said.

“If you look at reductions in recurrence with radiation, essentially all of that reduction is in the first 5 years,” he explained. “A 5-year follow-up study is going to be adequate for any breast control technique, be it radiation or ablative technology.”

A multicenter phase II study, called ABLATE, is under way with radiofrequency ablation as the sole treatment after surgery for small breast tumors. The strategy would likely not be suitable for larger tumors, according to Wilson.

A randomized phase III trial would be best, but the strategy could catch on without one, if history is any guide, Beitsch suggested, pointing to sentinel node biopsy as an example of a shift based initially on common sense rather than evidence.