Radiofrequency ablation treatment for small breast cancer

Abstract #5155 Aims: There is increasing demand for minimally invasive and non-surgical treatment in breast cancer. Although radiofrequency (RF) ablation seems the most promising non-surgical treatment for small breast cancer, its relevance has been controversial. This study was performed to determine the feasibility and the safety of treating small breast cancer with RF ablation. Methods: In this study, all patients had a localized breast cancer of 2.0 cm or less in greatest diameter. The tumors were confirmed to be localized lesions by ultrasonography, mammography, and enhanced MRI or CT. Before treatment, core needle or mammotome biopsy was performed to obtain the tumor tissue for establishing the histological diagnosis and the status of hormonal receptors and HER-2 expression. A model 15000 generator with a seven-array Starbusrt XL needle-electrode Model 70 (RITA Medical System) was used for RF ablation. In the first series, 17 patients underwent RF ablation and sentinel lymph node (SLN) biopsy followed immediately by wide resection (n=13) or total mastectomy (n=4). Axillary dissection was performed in 5 patients with positive SLN. On the other hand, 15 patients underwent RF ablation and SLN biopsy in the second series. Axillary dissection was performed in 3 patients with positive SLN. The ablated lesion was excised by mammotome after several months later. The ablated tumor tissue was examined histologically with H&E staining and NADH-diaphorase staining to assess tumor cell viability. Patients who underwent wide resection or RF ablation alone received breast irradiation, and all of the patients were treated with systemic therapy according to the St. Gallen recommendation. Results: Histological examination with H&E staining revealed a spectrum of changes ranging from complete coagulation necrosis to normal-appearing tumor cells, but NADH-diaphorase staining revealed no viable tumor cells in the either series. No patient developed to local or breast recurrence in the first series with a median follow-up period of 46 months (range: 34-61 months), and in the second series with a median follow-up period of 23 months (range: 12-32 months). However, one patient in the first series and another in the second series developed to the distant metastases, although they are alive with systemic treatment. The cosmesis of conserved breast was excellent in the second series more than in the first series, and no adverse effect such as skin burn or persistent hard lump