Sentinel lymph node biopsy after neoadjuvant chemotherapy

Background: We surveyed single-center and multi-center studies pertaining to sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy to compare the results with those of our current study to evaluate the feasibility and accuracy of SLNB after neoadjuvant chemotherapy. Methods: From October 2001 to July 2003, 80 patients who had neoadjuvant chemotherapy underwent curative surgery and axillary lymph node dissection (ALND) after SLNB at the Center for Breast Cancer, National Cancer Center. A MEDLINE search was performed using the keywords breast cancer, sentinel lymph node biopsy, and neoadjuvant chemotherapy. Results: Our results showed that 42 (52.6%) of 80 patients had downstaging of the primary tumor; 9 patients (11.3%) had pathologic complete response (pCR) and 33 (41.3%) had pathologic partial response (pPR). 26 patients (32.5%) showed complete axillary clearance after neoadjuvant chemotherapy. Among them, 5 patients (6.3%) revealed pCR of both the primary tumor and axillary metastasis. SLNB was successful in 61 of 80 patients (76.3%) and there were 3 false negatives, yielding a false negative rate (FNR) of 7.3% (3/41), a negation prediction value (NPV) of 87.0% (20/23), and an accuracy of 95.1% (58/61). Thirteen out of 16 studies retrieved by to MEDLINE pertaining SLNB after neoadjuvant chemotherapy concluded its feasibility and accuracy with a identification rate of 82%-100% and a FNR of 17-100%. Conclusion: Most studies, including ours, concluded that SLNB after neoadjuvant chemotherapy is accurate and could be an alternative to ALND.