Radiofrequency ablation treatment for small breast cancer.

Abstract 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&amp;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&amp;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 was observed in the second series. Conclusions: RF ablation is feasible for small breast cancer. To achieve wide acceptance, however, further studies are needed to determine whether the use of RF ablation for small breast cancer can provide local control and survival rates equivalent to those of conventional breast-conserving treatment. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5155.</jats:p

Abstract P4-15-05: Long-term outcome of breast cancer patients treated with radiofrequency ablation

Abstract Background: Radiofrequency ablation (RFA) is considered to be the most promising non-surgical ablation technique for the treatment of small breast cancer. In feasibility studies, the ablated tumor was surgically removed after RFA, and the tumor cell viability were assessed by histological and/or immunohistological examinations. However, these assessments of tumor viability do not take the place of long-term follow-up in patients treated with RFA alone, because they do not allow for them to be followed up for recurrence after RFA, or to determine if there were any undesirable complications of this procedure. At present, few data are available regarding long-term follow-up of patients treated with this modality. Methods: Since 2005, we have performed RFA and sentinel lymph node (SLN) biopsy in 19 cases with invasive breast cancer less than 2.0 cm in greatest diameter. After SLN biopsy, a primary electrode (seven-array model 70 Starburst needle electrode; RITA Medical Systems, Mountain View, CA) was inserted into the tumor under real-time US guidance. Then, the prongs of the needle electrode were deployed over a distance of 3 cm in all cases, and the RF generator (RITA model 1500) was activated and set to automatic, with power at 20 W, temperature of 95°C, and an ablation time of 15 min. Axillary lymph node dissection (ALND) was performed in patients with positive SLNs. Several months after RFA therapy, the ablated tumor tissue was excised by multiple mammotome biopsy and examined histologically or immunohistochemically with H&amp;E staining, nicotinamide adenine dinucleotide (NADH)-diaphorase staining, and single-stranded (ss) DNA staining. All cases were followed-up after breast radiation and systemic therapies. Results: The mean tumor size based on the ultrasonographic maximum dimension was 1.3 cm (range: 0.5–2.0 cm). Although complete response was histologically confirmed in only 8 cases, NADH-diaphorase and ssDNA staining did not demonstrate any viable tumor cells in any of the ablated lesions. At a mean follow-up of 60 months (follow-up range, 37–82 months), there were no cases of in-breast recurrence, although one patient died due to hepatic metastases. Cosmesis of the conserved breast was excellent or good in all of the cases, but a hard lump was persistent after RFA in half of the cases. Conclusions: The long-term outcome of patients treated with RFA is encouraging with regard to cosmesis and local control. However, a persisted lump can cause patient discomfort, anxiety and fear. Therefore, further studies are needed to establish the optimal technique. Moreover, a prospective study will be required to determine the equivalency in local recurrence rates between the RFA therapy and conventional breast-conserving treatment. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-15-05.</jats:p