Breast carcinoma in men is very uncommon compared to breast cancer in women, accounting for less than 1% of cancers in men and less than 1% of all breast cancers in general.
During childhood, the female and male mammary glands have the same characteristics. During puberty, mammary gland development occurs in females due to increased estrogen levels. In men, increased testosterone results in the mammary gland consisting basically of subcutaneous fatty tissue and an atrophic mammary gland remnant, and it is precisely this remnant that can degenerate into breast cancer in men.
Risk factors for breast cancer in men
Age is a risk factor. Breast cancer risk increases with age. In the United States, male breast cancer usually occurs on average 5 to 10 years later than in women.
Family history of breast cancer and the presence of genes predisposing to the development of breast cancer, BRCA1, but particularly BRCA2, are the most important risk factors. Other genes such as PALB2 or CHEK2 could also be involved, though conclusive data are not yet available.
Risk factors also include diseases that may cause increased estrogen levels in humans, such as Klinefelter syndrome, obesity, intake of exogenous estrogens or testosterone, and cirrhosis of the liver.
Clinical characteristics of the disease
In most cases, breast cancer is diagnosed by the appearance of a non-painful nodule under the skin of the breast area. Due to the patients’ lack of suspicion of breast cancer, nodules evolve over time, causing changes in the skin and/or areola of the nipple. For the same reason, it is common for the axillary nodes to be affected.
In the vast majority of cases, they are hormonal tumors, but any histological type may occur. The prognosis of the disease will depend on the stage and the specific type.
Treatment of male breast cancer
Treatment of localized disease includes mastectomy and conservative treatment or tumorectomy. In most cases, it is treated with mastectomy since men have very small breasts and the cosmetic result usually does not involve major changes. Radiation therapy can be used in cases where indicated, exactly as in female breast cancer.
If chemotherapy is used, the same regimens are used as for female breast cancer.
Tamoxifen is used as adjunctive therapy to surgery if necessary, but aromatase inhibitors may be used if tamoxifen is medically contraindicated.