Breast cancer is less common in men than in women. It represents 0.5 to 1 percent of all breast cancers diagnosed each year. Men develop the disease at a later age than women.
As with breast cancer in women, a history of breast cancer in a first-degree relative is associated with an increased risk of breast cancer among men as well. Excessive estrogen stimulation may be due to hormonal treatments (for example, compounds containing estrogen or testosterone), liver dysfunction, obesity, marijuana use, thyroid disease or a hereditary condition such as Klinefelter syndrome.
Testicular conditions associated with an increased risk of breast cancer in men include orchitis, undescended testes (cryptorchidism) and testicular injury. Although speculative, it may be thought that these conditions are associated with a disturbed androgen-estrogen ratio and low androgen production.
Male breast cancer is typically diagnosed at a more advanced stage than female breast cancer. This is most likely because of the lack of awareness that men can develop breast cancer and that there are no routine screening examinations.
Most men with breast cancer usually present with a painless lump accompanied by nipple involvement. There may be associated skin changes, including nipple retraction and fixation of the lump to the skin or underlying tissues. Enlargement of lymph nodes in the armpit can typically be seen in advanced-stage breast cancer cases.
The approach to a male patient who presents with a suspicious breast lump is similar to that for women and includes mammography, breast ultrasound and biopsy.
Because of the small volume of breast tissue, men with early-stage breast cancer undergo simple mastectomy and axillary lymph node biopsy instead of breast-conserving treatment. As in women, chemotherapy, radiotherapy to the chest wall and regional lymph nodes, hormone therapy (for those with hormone receptor-positive disease) and targeted therapy (if the Her2-neu receptor is positive) may be recommended after surgery.
Men with regionally advanced breast cancer receive chemotherapy before surgery. In addition, patients with early-stage disease may be suitable candidates for chemotherapy before surgery if the cancer is triple-negative or HER2 receptor-positive.
Although breast cancer in men was once thought to be associated with a much worse prognosis than in women, most current studies on male and female breast cancer support that men who are carefully matched with women for age at diagnosis, stage and grade have similar survival. As in women, stage, tumor size and axillary lymph node status are the most important factors affecting prognosis in breast cancer in men.
In general, men who have been treated for breast cancer should be followed up in a similar way to women. However, the role of screening in men with a history of breast cancer is unclear, and the man’s preferences and values should be taken into account in decision-making.
