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.
Generally, men with breast cancer have lower survival rates — probably because the disease spreads rapidly due to scanty tissue in the breast area. While 83% women are likely to be alive five years after early-stage diagnosis and treatment, the percentage would be 73% for men."