Prospective Phase II Multicenter Trial of Ablation after Breast Lumpectomy Added To Extend (ABLATE) Intraoperative Margins for the Sole Local Treatment of Breast Cancer.

Abstract

Excision followed by radiofrequency ablation (eRFA) is an intraoperative method that utilizes intracavitary hyperthermia to create an additional tumor-free zone around the lumpectomy cavity in patients with breast cancer, similar to partial breast irradiation. We hypothesized that intraoperative eRFA extends the "final" tumor-free margin, decreases local recurrence, and maintains cosmesis without the need for radiation (XRT). Patients with unifocal ER+PR+HER2- or DCIS tumors less than or equal to 3 cm with clinically negative nodes were included. After standard lumpectomy, the RFA probe was deployed 1 cm circumferentially into the walls of the lumpectomy cavity. RFA was performed at 100°C for 15 min, followed by validated intraoperative Doppler sonography. Pain and cosmesis were assessed with the Radiation Therapy Oncology Group (RTOG) scales. A total of 242 subjects were accrued to the study, with a median follow-up of 44 months (range 12-96 months); 60% were invasive ductal cancer (IDC), and 33% were ductal carcinoma in situ (DCIS). The average size was 1.1 ± 0.6 cm (0.2-3 cm). Reexcision for positive margins was < 5%. In-breast recurrence rate was 2.9%. Breast pain at 6 months was 19% with RFA combined with XRT versus 1.7% with RFA alone (p < 0.05). Cosmesis was good or excellent in 89% of subjects. A majority of the subjects avoided whole breast XRT and mastectomy. Results indicate that eRFA, in lieu of XRT, is safe and effective, resulting in ~fivefold lower pain. By completing therapy in the operating room, eRFA can potentially enhance patient access and compliance, alleviate financial stress, and deliver superior cosmetic and quality-of-life outcomes.