Male breast cancer

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Many people do not realize that men have breast tissue and that they can develop breast cancer. Male breast cancer is rare, accounts for about 1% of all cases.

The treatment of male breast cancer is similar to female breast cancer with the exception that surgery, for obvious reasons consists of mastectomy and the majority of males will require post operative radiotherapy. The indications for chemotherapy, Herceptin and hormone therapies are the same (see treatment of breast cancer).

Presenting features: Usually presents as a lump in under the nipple or an eczema like rash around the nipple.  Not all cases of breast swelling (known as gynaecomastia) are cancer, other causes include:

Other causes of breast swelling in males (gynecomastia): This is common among teenage boys, it is due to changes in hormone balance during adolescence. It can be uncomfortable but as long as no discrete lump is felt usually no treatment is needed as it tends to resolve spontaneously. Tumours or diseases of certain endocrine (hormone-producing) glands cause a man's body to produce more estrogen (the main female hormone).  Diseases of the liver, which is an important organ in male and female hormone metabolism, can change a man's hormone balance and lead to gynaecomastia. Obesity may be another cause of elevated estrogens in men. Some drugs can cause gynaecomastia - used to treat prostate cancer (casadex, stilboestrol) ulcers and heartburn, high blood pressure, and heart failure. A rare genetic disorder called Klinefelter syndrome, can lead to gynaecomastia and increase a man's risk of developing breast cancer.

Risk factors: In most cases the cause is unknown but some associated risks include the following.

• Aging: Men with breast cancer average about 67 years old at the time of their diagnosis.
• Family history of breast cancer: Breast cancer risk is increased if other members of the family ("blood relatives") have had breast cancer. About 20% of men with breast cancer have close male or female relatives with the disease. The gene mutation (change) BRCA2, which is responsible for some breast cancers in women, probably accounts for about 10% of breast cancers in men. BRCA1 mutations can also increase the risk of breast cancer in men but seems to be responsible for fewer cases than the BRCA2 gene. The clue to these mutations would be a strong family history of breast cancer, which often appeared at a young (under 60) age. Other gene mutations that have been thought responsible for some breast cancers in men are mutations in a gene called CHEK2. Klinefelter syndrome:  is a congenital condition that affects about 1 of 1000 men. Normally men have a single X chromosome along with their Y chromosome, while women have two X chromosomes. Men with this condition have more than one X chromosome. This causes their testicles to be smaller than usual and not produce functioning sperm cells, making them infertile develop gynaecomastia and have an increased risk of breast cancer.
• Radiation exposure: A man whose chest area has been exposed to radiation (usually for treatment of a cancer inside the chest, such as Hodgkin or non-Hodgkin lymphoma) has an increased risk of developing breast cancer.
• Alcohol: Heavy alcohol intake increases the risk of breast cancer in men
• Liver disease: The liver plays an important role in sex hormone metabolism by producing binding proteins that carry the hormones in the blood. These binding proteins affect the hormones' activity. Men with severe liver disease such as cirrhosis have relatively low levels of androgen activity and higher estrogen levels. Therefore, they may have an increased risk of developing gynecomastia and breast cancer.
• Estrogen treatment: Estrogen-related drugs are sometimes used in hormonal therapy for men with prostate cancer. This treatment may slightly increase their breast cancer risk. However, this risk is small compared with the benefits of this treatment in slowing the growth of prostate cancer. Men taking high doses of estrogens as part of a sex change procedure have a much higher breast cancer risk.
• Physical inactivity and obesity: Recent studies have shown that physical activity reduces women's breast cancer risk and that breast cancer risk is increased by obesity during adult life. Obesity is probably a risk factor for male breast cancer. The reason is that fat cells convert male hormones (androgens) into female hormones (estrogens). This means that obese men have higher levels of estrogens in their body. Some obese men may notice that they don't have to shave as frequently as other men. They might also have difficulty fathering children because they may be infertile. Regular exercise and maintaining a healthy weight reduces the risk of many diseases and cancers.