Male breast cancer (MBC) is rare, with an estimated 145 men diagnosed in Australia this year and up to 12% of these having a BRCA2 mutation. The median age at diagnosis for men is 71 years versus 60 years for women. Most men with enlarged breasts have lipomastia or pseudogynaecomastia.  Gynaecomastia refers to unilateral or bilateral breast tenderness due to hormonal changes. Conversely, MBC tends to present as unilateral, often nodular tumours located close to the nipple and bloody nipple discharge can occur.

Initial investigation includes ultrasound and mammography followed by core-biopsy of the primary lesion and often fine-needle biopsy of abnormal axillary nodes. Breast MRI may be helpful.

Common histologies include infiltrating ductal (90%) followed by papillary carcinomas (3%) and DCIS in 2% of patients. ER-positive disease accounts for 80% of patients and HER2-positive disease is uncommon (<5%).

Treatment is total mastectomy and sentinel node biopsy. If a patient presents with a larger mass, a PET-CT or CT and bone scan is necessary to assess loco-regional and distant disease and this often helps determine whether axillary dissection, sentinel node biopsy or IMC irradiation is required.

Most patients require post-mastectomy radiotherapy, as the disease is often advanced at presentation and obtaining clear margins can be difficult. Limited studies support the use of adjuvant tamoxifen and/or chemotherapy, but not aromatase inhibitors alone.  Herceptin is advisable if patient is HER2 positive, but studies are limited.

Follow-up and review in a family history clinic is important, as 12.5% of patients will develop a second cancer. BRCA2 mutation may account for increased risk of pancreatic, prostate and gastric cancer.

There is significant psychological impact from MBC with issues including “contested masculinity”, “concealment” and “interacting with health services” for patients facing a disease dominated by pink and the female sex. Increasing awareness is essential.