Male breast cancer is rare, accounting for less than 1% of all cases of breast cancer. The average age of men who are found to have breast cancer is between 60 and 70 years of age, although men of all ages can develop breast cancer.
Risk factors for male breast cancer appear to include exposure to radiation, the administration of estrogen (a hormone), and diseases associated with hyperestrogenism (producing too much estrogen), such as cirrhosis (liver disease) or Klinefelter's syndrome (a genetic disorder). Male breast cancer tends to run in families, with the risk of breast cancer increasing in men who have multiple female relatives who have had breast cancer. Men who have the BRCA2 genetic alteration appear to have a higher risk of developing breast cancer.
The types of breast cancer found in men are similar to those seen in women. The most common type of breast cancer is infiltrating ductal cancer (cancer that has spread beyond the cells lining ducts in the breast). Intraductal cancer (abnormal cells found in the lining of a duct; also called ductal carcinoma in situ), inflammatory cancer (a rare cancer in which the breast looks as if it is inflamed because of its red appearance and warmth), and Paget's disease of the nipple (the tumor has grown from ducts beneath the nipple onto the surface of the nipple) have also been seen in men. Lobular cancer in situ (abnormal cells found in the one of the lobes or sections of the breast) has not been seen in men. Breast cancer in men is staged (tests done to find out if the cancer has spread from the breast to other parts of the body) the same as it is in women (refer to the PDQ summary on Breast Cancer Treatment for more information.
Overall survival for men who have breast cancer is similar to that of women with breast cancer. Breast cancer in men, however, is frequently diagnosed at a later stage, affecting the likelihood of survival.
Types of Treatment
There are treatments for men with breast cancer. Four types of treatment are used:
- surgery (taking out the cancer in an operation)
- radiation therapy (using high-dose x-rays to kill cancer cells)
- chemotherapy (using drugs to kill cancer cells)
- hormone therapy (using drugs that change the way hormones work or taking out organs that make hormones, such as the testicles)
Surgery for men with breast cancer is usually a modified radical mastectomy (removal of the breast, the lining over the chest muscles, and sometimes part of the chest wall muscles). In addition, some of the lymph nodes (small organs that fight infection and disease) under the arm may also be removed and sent to a laboratory to be examined under a microscope by a doctor of pathology to see if the lymph nodes contain any microscopic cancer cells.
Radiation therapy is the use of high-energy x-rays to kill cancer cells and shrink tumors. Radiation will usually be given by a machine outside the body (external radiation therapy).
Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be taken by mouth or it may be put into the body by inserting a needle into a vein or muscle. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells outside the breast area.
Hormone therapy may be given if tests show that the breast cancer cells have estrogen receptors or progesterone receptors (certain proteins in cancer tissue). Hormone therapy is used to change the way hormones in the body help cancers grow. This may be done by using drugs that change the way hormones work or by surgery to take out organs that make hormones, such as the testicles. Hormone therapy with tamoxifen is often given to patients with early stages of breast cancer.
Initial surgical management
Most men diagnosed with breast cancer will receive a modified radical mastectomy followed by removal of some of the lymph nodes located under the arm.
Even if the doctor removes all the cancer that can be seen at the time of the operation, the patient may be given radiation therapy, chemotherapy, and/or hormone therapy after surgery to try to kill any cancer cells that may be left. Therapy given after an operation when there are no cancer cells that can be seen is called adjuvant therapy.
If cancer is found in the lymph nodes, treatment consisting of chemotherapy plus tamoxifen (to block the effect of estrogen) and other hormone therapy appears to increase survival in men as it does in women. The patient's response to hormone therapy depends on the presence of hormone receptors in the tumor. The majority of breast cancers in men have these receptors. Hormone therapy is usually recommended for male breast cancer patients, but it can have many side effects, such as hot flashes and impotence (the inability to have an erection adequate for sexual intercourse).
Locally recurrent disease
For locally recurrent disease (cancer that has come back in a limited area after treatment), treatment is usually surgery and radiation therapy combined with chemotherapy.
For distant metastases (cancer that has spread to other parts of the body), hormone therapy, chemotherapy, or a combination of both have shown some success. Hormone therapy may include:
- Orchiectomy (removal of the testicles to decrease hormone production)
- Luteinizing hormone-releasing hormone with or without total androgen blockade (to decrease the production of sex hormones)
- Tamoxifen for cancer that is estrogen-receptor positive
- Progesterone (a female hormone)
- Aminoglutethimide (reduces the production of estrogen)
Hormone therapies may be used in sequence (one after the other). Standard chemotherapy regimens may be used if hormone therapy does not work. Men usually respond to therapy no differently than women who have breast cancer.
Source: National Cancer Institute, National Institutes of Health