Positive progesterone receptors and cell proliferation index: an independent association with breast cancer in males.

BACKGROUND AND AIM: Breast cancer in males is an uncommon tumor whose management is extrapolated from that used in female breast cancer. This study compared the histopathological and immunohistochemical features of symptomatic breast cancers in males and females. PATIENTS AND METHODS: A comparison was made between variables of breast cancers from 58 males and 155 females. A descriptive study, a bivariate analysis, and a multivariate analysis using logistic regression were performed. RESULTS: No differences were found in staging. Significant differences were seen in age (p<0.0005), proportion of papillary carcinoma (p=0.038) and proportion of tumors with an associated intraductal component (p=0.002). There was a greater proportion of males expressing estrogen (p=0.038) and progesterone (p<0.0005) receptors in their tumors, with a significantly higher proliferation index (p<0.0005). CONCLUSIONS: Breast cancer in males should be considered a condition biologically different from female breast cancer as a result of factors related to the different hormonal influences, reflected mainly in immunohistochemical differences.