Male breast cancer is a disease in which malignant (cancer)
cells form in the tissues of the breast.
Breast cancer may occur in
men. Men at any age may develop breast cancer, but it is usually detected
(found) in men between 60 and 70 years of age. Male breast cancer makes up less
than 1% of all cases of breast cancer.
The following types of breast cancer are found in men:
Lobular carcinoma in
situ (abnormal cells found in one of the
lobes or sections of the breast),
which sometimes occurs in women, has not been seen in men.
Male breast anatomy: Anatomy of the male breast showing the nipple, areola, fatty tissue, and ducts. Nearby lymph nodes, ribs, and muscle are also shown.
Radiation exposure, high levels of estrogen, and a family
history of breast cancer can increase a man’s risk of developing breast cancer.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for breast
cancer in men may include the following:
Having several female relatives who have had breast cancer,
especially relatives who have an alteration of the BRCA2gene.
Male breast cancer is sometimes caused by inherited gene
The genes in cells carry the hereditary information that is received from a person’s parents. Hereditary breast cancer makes up approximately 5% to 10% of all breast cancer. Some altered genes related to breast cancer are more common in certain ethnic groups.
Men who have an altered gene related to breast cancer have an increased risk of developing this disease.
Tests have been developed that can detect altered genes. These genetic tests are sometimes done for members of families with a high risk of cancer. See the following PDQ summaries for more information:
HER2 test: A test to measure the amount of HER2 in cancer tissue. HER2 is a growth factorprotein that sends growth signals to cells.
When cancer forms, the cells may make too much of the protein, causing more cancer cells to grow. If cancer is found in the breast, tissue from the tumor is checked in the laboratory to find out if there is too much HER2 in the cells. The test results show whether monoclonal antibodytherapy may stop the cancer from growing.
Survival for men with breast cancer is similar to survival for
women with breast cancer.
Survival for men with breast cancer is similar to that for women
with breast cancer when their stage
at diagnosis is the same. Breast
cancer in men, however, is often diagnosed at a later stage. Cancer found at a
later stage may be less likely to be cured.
Certain factors affect prognosis
(chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on
of the cancer (whether it is in the breast only or has spread to other places
in the body).
The type of breast cancer.
Estrogen-receptor and progesterone-receptor levels in the tumor tissue.
Whether the cancer is also found in the other breast.