Avoiding risk factors and increasing protective factors may help prevent cancer.
Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.
Incidence and Mortality
Estimated new cases and deaths from breast cancer (men only) in the United States in 2013:
New cases: 2,240.
Male breast cancer is rare. Less than 1% of all breast carcinomas occur in men.[3,4] The mean age at diagnosis is between 60 and 70 years, though men of all ages can be affected with the disease.
Predisposing risk factors  appear to include radiation exposure, estrogen administration, and diseases associated with hyperestrogenism,...
NCI's Breast Cancer Risk Assessment Tool uses a woman's risk factors to estimate her risk for breast cancer during the next five years and up to age 90. This online tool is meant to be used by a health care provider. For more information on breast cancer risk, call 1-800-4-CANCER.
The following risk factors may increase the risk of breast cancer:
Estrogen (made in the body)
Estrogen is a hormone made by the body. It helps the body develop and maintain female sex characteristics. Being exposed to estrogen over a long time may increase the risk of breast cancer. Estrogen levels are highest during the years a woman is menstruating. A woman's exposure to estrogen is increased in the following ways:
Early menstruation: Beginning to have menstrual periods at age 11 or younger increases the number of years the breast tissue is exposed to estrogen.
Late menopause: The more years a woman menstruates, the longer her breast tissue is exposed to estrogen.
Late pregnancy or never being pregnant: Because estrogen levels are lower during pregnancy, breast tissue is exposed to more estrogen in women who become pregnant for the first time after age 35 or who never become pregnant.
Hormones, such as estrogen and progesterone, can be made into a pill form in a laboratory. Estrogen, progestin, or both may be given to replace the estrogen no longer made by the ovaries in postmenopausal women or women who have had their ovaries removed. This is called hormone replacement therapy (HRT) or hormone therapy (HT). Combination HRT/HT is estrogen combined with progesterone or progestin. This type of HRT/HT increases the risk of breast cancer. Women taking combination HRT/HT also may be more likely to have an abnormal mammogram. Studies show that when women stop taking estrogen combined with progesterone, the risk of breast cancer decreases.