Sentinel node biopsy for axillary management after neoadjuvant therapy for breast cancer: a single-center retrospective analysis with long follow-up.

PURPOSE: Sentinel node biopsy (SNB) after neoadjuvant therapy (NAT) for breast cancer remains controversial. We conducted a retrospective study of patients who underwent SNB after NAT to evaluate the effectiveness of this procedure.

METHODS: A consecutive 105 women with locally advanced breast cancer (cT1-4, cN0-3, M0) were treated with NAT between 2006 and 2015. The subjects were 80 of these patients who became or remained clinically node-negative after NAT, 53 of whom had axillary management determined by SNB (group A) and the other 27 underwent axillary lymph node dissection (ALND) without SNB (group B). SNB was performed using a modified dye method.

RESULTS: The sentinel node (SN) identification rate was 94.3% and the mean number of removed SNs was 2.4. ALND was avoided in 33 patients, who were confirmed as SN-negative. There was no difference in recurrence-free and overall survival rates between groups A and B (p = 0.71 and p = 0.46, respectively) during the median follow-up time of 63 months. Of the 33 patients who did not undergo ALND, 10 suffered recurrence (33%). One patient (3%) had recurrence in an axillary lymph node and four had recurrence in a supraclavicular lymph node.

CONCLUSION: Axillary SNB after NAT did not affect the axillary failure rate or the prognosis. SNB may be a reliable procedure, even after NAT.