Male breast cancer (MBC) is rare, with the peak age of onset at 71 years. BRCA2 mutations are more frequent than BRCA1 with 20% of cases giving a family history. Risk factors for MBC are poorly understood and include working in high-ambient temperatures and exhaust fume exposure. MBC is associated with hyperoestrogenic states found in liver disease, Klinefelter's syndrome, gonadal dysfunction or obesity. Most information on treatment of MBC is derived from large randomized trials carried out in female patients. The small numbers of MBC seen in any unit annually has precluded significant trials being carried out.

Diagnosis and treatment of MBC is similar to that of female patients, but men tend to be treated with mastectomy rather than breast-conserving surgery. The mainstay of adjuvant therapy or palliative treatment for advanced disease is endocrine, mostly tamoxifen. Prognosis of male patients is equal to that of stage-matched women, but men tend to fare worse because of delay in presentation, leading to a large proportion of patients presenting with stage III or IV disease. Increased input is needed for psychological support for male breast cancer patients. Specific therapeutic questions about MBC need international trials to obtain meaningful answers.