A Multi-Center Prospective Study of Radiofrequency Ablation Without Surgical Excision for Small Breast Carcinomas.

e12043 Background: The most promising nonsurgical ablation technique is radiofrequency ablation (RFA). Our preliminary studies of RFA followed by standard surgical resection have indicated that this technique is effective for small ( ≤ 2cm) breast tumors without extensive intraductal components (EIC). Methods: To determine if RFA is oncologically and cosmetically appropriate for the local treatment of primary breast carcinoma, this multi-center prospective study used RFA as the sole local treatment of breast tumors ≤ 1.0cm in size on ultrasound and MRI. Exclusion criteria include receiving of preoperative chemotherapy, or the presence of invasive lobular carcinoma or invasive ductal carcinoma with suspicious EIC. After confirmation that the standard baseline core biopsy for diagnosis and measurement of tumors markers (ER, PgR, HER-2/neu and Ki-67) have been obtained, the patients were scheduled RFA. All patients received adjuvant radiation therapy. The use and choice of systemic therapy will be based on the information from the baseline biopsy specimens. 58 patients with small tumors that are clearly identifiable and measurable by ultrasound and MRI were enrolled. The response to ablation was evaluated with vacuum-assisted biopsies and imaging studies every 3 months during the first year. The long-term outcomes were assessed using imaging studies every 6 months after 5 years. Results: Of the 58 patients who participated in this study, 55 completed the protocol. In 48 of the 55 (87%) treated patients, successful tumor ablation, as determined by negative findings on vacuum-assisted biopsies and imaging studies, was confirmed. The remaining 7 patients with biopsies positive for residual tumor underwent surgical resection. There were no local or distant recurrences in treated 55 patients with a median follow up of 37 months (range 24-61 months). Conclusions: RFA can be safely used alone in patients with small breast tumors, provided that local tumor control must be regularly assessed by image-guided vacuum-assisted biopsies after ablation. RFA has several potential advantages over lumpectomy for the treatment of early stage breast cancer. Clinical trial information: UMIN000008608.