Background: We investigated predictors for axillary node metastasis at breast surgery after neoadjuvant chemotherapy (NAC) in patients with pre-chemotherapy-sentinel node positive breast cancer.
Methods: Eighty-two patients were diagnosed as having positive sentinel lymph node (SLN), who had axillary lymph node dissection (ALND) performed after combination anthracycline/taxan based NAC, between 2002 and 2009.
Results: Eighteen (22.0%) of the 82 patients had residual axillary metastases after NAC. Multivariate analysis revealed that SLNs status before NAC was an important factor in predicting residual axillary metastases. Predictors of residual nodal disease were the number of macrometastases and the percentage (>50%) of positive SLNs in all SLNs. Among a subgroup of hormone-receptor positive and HER2-negative tumors, the risk of residual nodal metastases were high sensitivity of hormone receptor, with more than 50% of tumor cells staining positive for ER and PgR.
Conclusion: Patients with two or more positive SLNs before NAC had a high risk of residual nodal metastasis after NAC.