Radiofrequency ablation could become an option for some patients facing adjuvant radiation after breast-conserving surgery for invasive breast cancer, the results of a phase II trial suggest.
Excision followed by radiofrequency ablation (eRFA) was at least as effective as radiation therapy following lumpectomy in preventing local tumor recurrence in the single-arm study of 73 patients who underwent breast conserving surgery, according to investigators. Only one patient had an in-site recurrence while three had recurrences, they reported at the annual meeting of the American Society of Breast Surgeons.
"For selected breast cancer patients undergoing breast-conservation therapy, eRFA is an attractive alternative to breast irradiation," said Dr. Misti Wilson at a press briefing.
The intraoperative procedure of excision followed by radiofrequency ablation employs heat to create an additional tumor-free zone, approximating the zone treated by brachytherapy, around the lumpectomy cavity. Its benefits include reduced likelihood of the need for re-excision and for additional radiation; lower cost, compared with radiation; and good to excellent cosmetic results, said Dr. Wilson, a breast surgical oncology fellow at the University of Arkansas in Little Rock.
The study enrolled 73 patients with tumors of less than 3 cm. Median follow-up was 55 months. All underwent standard lumpectomy followed by radiofrequency ablation, in which the RFA probe was deployed 1 cm circumferentially into the walls of the lumpectomy cavity and maintained at 100 degrees C for 15 minutes.
None of the patients received subsequent radiation or chemotherapy. Only those with grossly positive margins or residual calcifications on postoperative mammography were re-resected.
Among 19 patients who had inadequate margins, RFA spared 16 (84%) from additional surgery. Only three patients (4%) had to return to the operating room for resection because of grossly positive margins. There was just one in-site recurrence out of 73 patients, and 3 had recurrences elsewhere, Dr. Wilson reported.
Of 40 patients who scored their cosmesis, 18 (45%) reported excellent cosmetic results, 18 (45%) reported good results, and 4 (10%) reported fair cosmetic results.
"These findings show that this is a safe procedure, patients can have less repeat surgery, they have good cosmetic outcomes, and RFA may replace radiation therapy in patients with small tumors and are node negative," Dr. Wilson said in an interview.
The cost of eRFA is around $2,000 dollars. In contrast, standard whole breast radiation costs approximately $11,000, and partial breast around $18,000 depending upon site and location, she said.
The ABLATE trial is investigating eRFA in a larger patient population. To date, the trial includes five centers (Columbia University, N.Y; University of Kansas, Lawrence; Comprehensive Breast Care of San Diego, University of Arizona, Tucson; and Rockefeller Cancer Institute in Little Rock) and is actively recruiting and training additional sites.
Early results were presented in a poster by the primary investigator of both studies, Dr. V. Suzanne Klimberg, professor of surgery and pathology and director of the breast program at the University of Arkansas.
Of 55 patients (mean age 65 years) with ductal carcinoma in situ or invasive breast cancer with average tumor size 0.9 cm who underwent eRFA, 20 had positive margins: 14 had close margins (less than 2 mm), 2 had focally positive margins, and 4 had grossly positive margins. Of those, 15 were spared re-excision. Morbidity at 30 days was 7.2% and there were no deaths.
The University of Arkansas sponsored the study in collaboration with AngioDynamics, maker of the RFA delivery system.Dr. Wilson stated that she has no disclosures. Dr. Klimberg received research grants from AngioDynamics and retailers Fashion Footwear Association of New York and QVC.