Abstract P2-13-18: Oncologic outcome of 2,217 patients with breast cancer after negative sentinel lymph node biopsy without axillary lymph node dissection

Abstract

Abstract Background Sentinel lymph node biopsy (SLNB) is a standard method for nodal staging and enables to omit axillary lymph node dissection after negative sentinel lymph node (SLN). False-negative rate of SLNB has been reported as 5-7%. To dissolve the concerns regarding the axillary recurrence due to false-negative cases after negative SLNB, we investigated oncologic outcomes of a large number of breast cancer patients with negative SLN after SLNB. Methods A total of 2,475 patients with clinically node-negative breast cancer underwent SLNB at Severance hospitals between December 1998 and December 2013. 99-m Tc radiocolloid or blue dye was used in SLNB with periareolar intradermal injection technique. Intraoperative frozen examination of SLN was performed. If frozen test for SLN showed negative result, further axillary node dissection was omitted. Survival rates were estimated by the Kaplan-Meier method. Multivariate survival analysis was performed using the Cox-regression hazard model. Results Among 2,475 patients, 2,217 patients had no metastatic focus on SLN. A mean of 2.4 sentinel lymph nodes was dissected in all of the patients. At a median follow-up of 36 months, only 13 patients (0.6%) had axillary recurrence, and a median time to the recurrence was 20 months (range 7-45 months). During the follow-up period, 22 local, 16 regional, and 44 distant recurrences were observed. In multivariate analysis for axillary recurrence, tumor size and refusal of systemic therapy were demonstrated to be independent risk factors for axillary recurrence (hazard ratio (HR) 1.77, 95% confidence interval (CI), 1.08-2.89, P=0.024; HR 0.15, 95% CI, 0.03-0.75, P=0.021). Disease-free survival and axillary recurrence-free survival rates at 3 years were 96.5% (95% CI, 0.960-0.970) and 99.2% (95% CI, 0.990-0.994), respectively. Conclusions The axillary recurrence rate was very low in patients with negative SLN. Our findings supported that SLNB is a reliable procedure and its oncologic safety is not affected by the chance of axillary recurrence after negative SLNB. Citation Format: Jong Tae Park, Hak Min Lee, Sung Gwe Ahn, Seung Ah Lee, Joon Jeong. Oncologic outcome of 2,217 patients with breast cancer after negative sentinel lymph node biopsy without axillary lymph node dissection [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-13-18.