Abstract P1-01-22: Which cytologically proven node-positive breast cancer patients can avoid axillary lymph dissection after neaodjuvant chemotherapy?

Abstract

Abstract BACKGROUND: It is still controversial whether axillary lymph node dissection can be omitted after negative sentinel lymph node biopsy in breast cancer patients with clinically positive axilla at presentation treated with neoadjuvant chemotherapy (NAC). The aim of this study was to analyze whether SLN biopsy could be useful in these patients. METHODS: After NAC of 112 patients with cytology-proven axillary node metastasis at the time of diagnosis, SLNB using radioisotope and blue dye was performed including completion node dissection between 2008 and 2012. The results of SLNB and clinicopathological characteristics were analyzed for correlation with pathological axillary lymph node status. RESULTS: SLN was successfully identified in 107 (95.5%) patients. Tumor nonresponse and extensive residual nodal disease were found to be significantly associated with detection failure of sentinel nodes. Axillary status was predicted with 94% accuracy and a false negative rate of 8.7%. Axillary nodal status before NAC (cN2 versus cN12) was associated with higher false-negative rates (p = 0.02). Conversion to node-negative disease was achieved in 38 (35%) patients: 23% of patients with the luminal A subtype, 12% of patients with the luminal B, 39% of patients with the HER2-enriched, and 26% of patients with the triple-negative breast cancer subtype. The tripple negative and HER2-enriched breast cancer subtypes had a significantly better false negative rate and accuracy. CONCLUSIONS: SLNB was found to be technically feasible, but its routine use was not recommended for LABCs after NAC. However, acceptable performance was noted for tripple negative and HER2-enriched breast cancer patients presented with N1 axillary status in the beginning of NAC, and thus SLNB might be safely considered in these selected patients. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-22.