65PThe possibility of omitting axillary clearance by using indocyanine green fluorescence method in detection of sentinel lymph nodes in early-stage breast cancer

Background: The AMAROS trial and the ACOSOG Z0011 trial showed that axillary lymph node dissection (ALND) could be spared in certain breast cancer patients with sentinel lymph node (SLN) metastasis on condition with treatment by axillary radiotherapy and adjuvant systemic therapy. Sugie et al. reported that the indocyanine green (ICG) fluorescence method had a high SLN identification rate and a high number of SLNs. They founded that positive SLN was usually identified within the first 4 resected SLNs, which could safely replace axillary clearance for surgeons otherwise willing to perform further axillary treatment. However, the data of long-time observation of the ICG fluorescence method was few. We report the axillary recurrence rate and the rate of lymphedema after SLN biopsy using ICG fluorescence method to investigate to the possibility of sparing an ALND without residual positive nodes in axilla. Methods: From May 2011 to December 2015, a total of 500 patients (511 axillas) with clinically node-negative breast cancer were received SLN biopsy using combination with ICG fluorescence and radioisotope, and we analyzed 493 axilla. Results: The median number of resected SLNs was 4.27, and median number of positive SLN nodes was 0.23. Median follow-up duration was 41 months, and axillary recurrence occurred in 5 of 493 axillas (1.01%). Four patients in the SLN positive group were not conducted the standard adjuvant therapy because of patient’s preference. Seventy-eight patients had positive SLNs, and median number of positive SLNs in 78 patients was 2.39. Although ALND was omitted for all patients, the axillary recurrence was 2 of 78 patients (2.56%), all of whom adjuvant therapy were insufficient. Lymphedema after SLN biopsy occurred in 6 patients (1.2%), but all of them had low grade. Conclusions: Our data indicate that by SLN biopsy using ICG fluorescence method, the axially recurrence rate is low when treated with appropriate adjuvant therapy. Because positive SLN was usually identified within the first 4 resected SLNs, the axillary recurrence rate was low by resecting 4 SLNs, which suggests the possibility of omitting ALND without lymphedema. Legal entity responsible for the study: Akira Yamauchi Funding: None Disclosure: All authors have declared no conflicts of interest.