Common myths about breast cancer abound, relayed through word of mouth and the Internet, often frightening women unnecessarily.
Despite the rumors, you can't get breast cancer from electric blankets, deodorant, microwave oven use, or underwire bras, says the American Cancer Society (ACS). The National Cancer Institute (NCI) has found no association between induced and spontaneous abortions and breast cancer, dispelling another popular myth.
That's not to say your lifestyle doesn't matter. The ACS says that your health habits may play a role in helping to reduce your risk for this serious disease, and they're particularly important as you get older.
An American woman has a 1-in-8 lifetime risk of developing the disease, but overall lifetime risk increases dramatically after age 40. According to the ACS, about two out of three women with invasive breast cancer are age 55 or older when they are diagnosed.
A mammogram won't reduce your risk for breast cancer, but it can help detect the disease in its early, most treatable, stages. The benefits and limitations of mammography vary based on factors like age and personal risk. Experts have different recommendations for mammography. Currently, the U.S. Preventive Services Task Force (USPSTF) recommends screening every two years for women ages 50 to 74. The ACS recommends yearly screening for all women ages 40 and older. Talk with your doctor about your personal risk factors before making a decision about when to start getting mammograms or how often to get them.
In general, your risk for breast cancer nearly doubles if one or more close relatives on either your mother's or your father's side developed the disease before menopause or have had ovarian cancer at any age. But other factors, such as being diagnosed with certain types of benign breast disease -- the extra growth of apparently normal cells -- can also increase your risk.
Risk factors for breast cancer include:
Genetics. Five to 10 percent of cases of breast cancer are hereditary, as a result of changes in genes (mutations). Women who inherit a BRCA1 or BRCA2 mutation have around an 80 percent chance of developing breast cancer during their lifetime. When they do develop cancer, it is often at a younger age than in women who are not born with one of these gene mutations.
Family history of breast cancer. According to the ACS, having one first-degree relative (a mother, sister, or daughter) with breast cancer about doubles a woman's risk. Having two first-degree relatives about triples her risk.
Previous breast cancer. A woman who has cancer in one breast is at higher risk for developing a new cancer in the other breast or in another part of the same breast, the ACS says.
Race. White women are slightly more likely to develop breast cancer than other groups, according to the ACS. African-American women are more likely to die of breast cancer. This may at least be partly because African-American women tend to have more aggressive tumors, although doctors aren't sure why this is the case. Asian, Hispanic, and Native American women have a lower risk of both developing and dying from breast cancer.
Breast biopsy results. A biopsy result of atypical hyperplasia increases a woman's breast cancer risk by four to five times; a result of proliferative breast disease without atypical hyperplasia increases the risk by 1.5 to 2 times. A biopsy result of fibrocystic changes without proliferative breast disease does not appear to increase breast cancer risk.
Radiation treatment. A woman who had radiation treatment in the chest area as a child or younger woman is at higher risk, the ACS says.
Menstruation history. Women who started their periods when they were younger than 12 and/or who went through menopause after age 55 are at slightly higher risk for breast cancer. This same risk applies to women who have not had children or had their first child after age 30, according to the ACS. This may be because risk could be related to the total number of menstrual periods a woman has during her lifetime.
Combined hormone therapy. Use of estrogen and progesterone, called combined hormone therapy (HT), for as little as two years puts a woman at higher risk for breast cancer, the ACS says, although the increased risk applies only to recent or current users of HT. Estrogen alone (ET) does not appear to increase the risk for breast cancer. Other health risks are associated with HT and ET. You should discuss the issue carefully with your health care provider to find out what is best for you.
Obesity. The relationship between obesity and breast cancer is complex. According to the ACS, risk appears to increase for women who gained weight after menopause, but not for those who have been overweight since childhood. Fat tissue, which produces a small amount of estrogen, may contribute to increased risk when present in higher amounts in the body.
Alcohol. The risk for breast cancer increases with the amount of alcohol consumed. When compared with women who are nondrinkers, women who have one alcoholic drink a day have a very small increase in risk, and those who have two to five drinks daily have about 1.5 times increased risk.