Background: To evaluate whether predictive factors of axillary lymph node metastasis in female breast cancer (BC) are similar in male BC.
Patients and methods: From January 1994 to May 2011, we recorded 80 non-metastatic male BC treated at Institut Curie (IC). We analysed the calibration and discrimination performance of two nomograms [IC, Memorian Sloan-Kettering Cancer Center (MSKCC)] originally designed to predict axillary lymph node metastases in female BC.
Results: About 55% and 24% of the tumours were pT1 and pT4, respectively. Nearly 46% demonstrated axillary lymph node metastasis. About 99% were oestrogen receptor positive and 94% HER2 negative. Lymph node status was the only significant prognostic factor of overall survival (P = 0.012). The area under curve (AUC) of IC and MSKCC nomograms were 0.66 (95% CI 0.54-0.79) and 0.64 (95% CI 0.52-0.76), respectively. The calibration of these two models was inadequate.
Conclusions: Multi-variate models designed to predict axillary lymph node metastases for female BC were not effective in our male BC series. Our results may be explained by (i) small sample size (ii) different biological determinants influencing axillary metastasis in male BC compared with female BC.