Breast Cancer

Breast cancer is the most common type of cancer among women in this country (other than skin cancer). Each year, more than 211,000 American women learn they have this disease. Each year, about 1,700 men in this country learn they have breast cancer. Scientists are studying breast cancer to find out more about its causes. They are looking for better ways to prevent, find, and treat it.

Cancer begins in cells. Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place. Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor. These masses can sometimes be cancerous.

No one knows the exact causes of breast cancer. Doctors often cannot explain why one woman develops breast cancer and another does not. They do know that bumping, bruising, or touching the breast does not cause cancer. Also, breast cancer is not contagious. Research has shown that women with certain risk factors are more likely than others to develop breast cancer. Risk factors for breast cancer include:

• Age: The chance of getting breast cancer goes up as a woman gets older. Most cases of breast cancer occur in women over 60.
• Family history: A woman's risk of breast cancer is higher if her mother, sister, or daughter had breast cancer. The risk is higher if her family member got breast cancer before age 40.
• Certain breast changes: Some women have cells in the breast that look abnormal under a microscope. Having certain types of abnormal cells (atypical hyperplasia and lobular carcinoma in situ [LCIS]) increases the risk of breast cancer.
• Gene changes: Changes in certain genes increase the risk of breast cancer. These genes include BRCA1, BRCA2, and others. Tests can sometimes show the presence of specific gene changes in families with many women who have had breast cancer.
• Reproductive and menstrual history:
  • The older a woman is when she has her first child, the greater her chance of breast cancer.
  • Women who had their first menstrual period before age 12 are at an increased risk of breast cancer.
  • Women who went through menopause after age 55 are at an increased risk of breast cancer.
  • Women who never had children are at an increased risk of breast cancer.
  • Women who take menopausal hormone therapy with estrogen plus progestin after menopause also appear to have an increased risk of breast cancer.
  • Large, well-designed studies have shown no link between abortion or miscarriage and breast cancer.
• Race: Breast cancer is diagnosed more often in white women than Latina, Asian, or African American women.
• Radiation therapy to the chest: Women who had radiation therapy to the chest (including breasts) before age 30 are at an increased risk of breast cancer. This includes women treated with radiation for Hodgkin's lymphoma.
• Breast density: Breast tissue may be dense or fatty. Older women whose mammograms (breast x-rays) show more dense tissue are at increased risk of breast cancer.
• Taking DES (diethylstilbestrol): DES was given to some pregnant women in the United States between about 1940 and 1971. (It is no longer given to pregnant women.) Women who took DES during pregnancy may have a slightly increased risk of breast cancer. The possible effects on their daughters are under study.
• Being overweight or obese after menopause: The chance of getting breast cancer after menopause is higher in women who are overweight or obese.
• Lack of physical activity: Women who are physically inactive throughout life may have an increased risk of breast cancer.
• Drinking alcohol: Studies suggest that the more alcohol a woman drinks, the greater her risk of breast cancer.

Many risk factors can be avoided. Others, such as family history, cannot be avoided. Women can help protect themselves by staying away from known risk factors whenever possible.  For more information on breast cancer, please visit: http://www.cancer.gov/cancertopics/wyntk/breast/. Contact your healthcare provider if you notice changes in your breasts.