Most breast cancers in men are ductal carcinomas. Ductal means the cancer started in the milk pipes of the breast, called ducts. These cancers are usually invasive because they start inside the duct and then break through the wall of the duct, growing into the normal surrounding breast tissue.
All data were analyzed using SPSS (v22.0). We used χ2 tests (and Fisher’s exact test, if necessary) to analyze numerical data. The survival times were compared among different groups using a Kaplan-Meier survival curve (log-rank test).