Applicability of two different validated models to predict axillary non-sentinel lymph node status by sentinel node biopsy in a single Italian center

Background The necessity of complete axillary lymph node dissection (CALND) after sentinel lymph node biopsy (SLNB) for women with sentinel lymph node metastases is a matter of debate because non-sentinel lymph nodes after CALND contain no further metastases in about 50 % of cases. Our study aims to determine the applicability in our setting of two different validated nomograms to predict axillary lymph node status after SLNB. Methods We collected data about all women who underwent SLNB in our Department of Surgery from 2007 to 2010, focusing on tumor, patient, and breast characteristics. Data was analyzed by R (version 2.15.2); p < 0.05 was considered significant. Results Among 511 women who underwent SLNB, 126 received CALND due to sentinel lymph node metastasis, and 73.0 % of these had no further metastatic non-sentinel lymph node. The area under the receiver operating characteristic (ROC) curves for the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram and the Tenon score were 78.5 % (95 % CI 70.1-86.8 %) and 77.0 % (95 % CI 67.9-86.0 %) (p = 0.678), respectively. Conclusions Both the MSKCC nomogram and the Tenon score were predictive for the axillary non-sentinel lymph node status by SLNB. The MSKCC nomogram was the more accurate of the two and the Tenon score was the easier one to apply.