Reducing Your Risk for Breast Cancer

Common myths about breast cancer abound, relayed through word of mouth and the Internet, frightening women unnecessarily.

Despite the rumors, you can't get breast cancer from electric blankets, deodorant, microwave-oven use or under-wire 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 NCI, a 30- to 39-year-old woman has a 1-in-252 chance of developing breast cancer within the next 10 years; a 40- to 49-year-old woman, 1-in-68; a 50- to 59-year-old woman, 1-in-35; a 60- to 70-year-old woman, 1-in-27.

Screening mammogram

A mammogram won't reduce your risk for breast cancer, but despite recent controversy, it can help detect the disease in its early, most treatable, stages. The ACS recommends getting an annual mammogram if you're 40 or older and at average risk for breast cancer. The U.S. Preventive Services Task Force and the NCI recommend that women older than 40 have a mammogram every one to two years. If you have a higher than average risk, your health care provider may recommend you begin mammograms before age 40.

Some doctors recommend women get baseline mammograms at age 35 if they don't have any significant risk factors, the ACS says, but a mammogram at that age may not be helpful. Because younger women tend to have denser breast tissue, a mammogram is less likely to show anything abnormal. Overall, the risk for women younger than 40 is low, so the ACS recommends they not expose themselves to even tiny amounts of radiation -- unless they're at increased risk for breast cancer, perhaps because they have a family history of it. In such cases, a mammogram before 40 may be appropriate.

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 -- also can increase your risk.

Risk factors for breast cancer:

• Genetics. Five to 10 percent of cases of breast cancer are hereditary, as a result of changes in genes (mutations), and slightly more than half of them are linked to mutations of the BRCA1 and BRCA2 genes. A woman with a mutation in one of these genes is at higher risk for developing breast cancer and certain other cancers.

• Family history of breast cancer. According to the ACS, 20 to 30 percent of women with breast cancer have a family member with the disease. If you have a relative (mother, sister, grandmother or aunt) who had breast cancer before age 50, your risk is increased. Your risk is also higher if you have two or more relatives with breast or ovarian cancer.

• 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, the ACS says. African American women are more likely to die of 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 or usual hyperplasia increases the risk by 1.5 to 2 times. A biopsy result of fibrocystic changes without proliferative breast disease does not 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 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.

• Hormone therapy. Using estrogen and progesterone, called combined hormone therapy (HT), for longer than five years puts a woman at slightly higher risk for breast cancer, the ACS says. 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, not for those who have been overweight since childhood. Fat tissue may contribute to increased risk because it can increase estrogen levels.

• 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 1½ times increased risk.

Be sure to tell all your health care providers that you have an increased risk.

Drug therapy

A woman with a family history of breast cancer or with a genetic mutation of a BRCA gene may be able to reduce her chances of breast cancer. The first step is genetic testing to find out if she has a mutation in either the BRCA1 or BRCA2 gene.

The drug tamoxifen, which blocks the effects of estrogen on breast tissue, has been used for years to treat some breast cancers. It is now used to reduce the incidence of breast cancer in high-risk women. But take heed, because tamoxifen can have serious side effects, such as early menopause, the ACS says.

Another anti-estrogen drug, raloxifene, may be effective at reducing the risk for breast cancer in postmenopausal women.

Tamoxifen and raloxifene may increase the risk for blood clots in veins and in the lungs. Tamoxifen also increases the risk for endometrial cancer.

Cancers caused by the BRCA1 gene mutation may not be prevented by tamoxifen or raloxifene.

Other types of drugs being studied for breast cancer prevention in postmenopausal women are aromatase inhibitors (AI). In premenopausal women, estrogen is produced by the ovaries and other tissues of the body, using a substance called aromatase. In postmenopausal women, estrogen is produced only by tissues in the body. Aromatase inhibitors do not block estrogen production by the ovaries, but they can block other tissues from making this hormone. That's why they are used mostly in women who have reached menopause, when the ovaries are no longer producing estrogen. Aromatase inhibitors they have side effects such as causing joint pain and stiffness, and bone loss, leading to a higher risk for osteoporosis. Currently, three AIs are approved by the U.S. Food and Drug Administration: anastrazole (Arimidex®), exemestane (Aromasin®) and letrozole (Femara®).

Clinical breast exams

Besides a mammogram, see your doctor for a clinical breast exam each year if you're age 40 or older, and every three years if you're 20 to 39, advises the ACS.

You may choose to perform breast self-exams monthly. It's not known how effective they are at detecting breast cancer, but doing them is associated with a greatly increased incidence of benign (non-cancerous) breast biopsies. If you notice a change, tell your doctor immediately.

Healthy weight

It's especially important for postmenopausal women to avoid being overweight, the ACS says, because that increases the risk for breast cancer.

Plus, maintaining a healthy weight throughout your life also can reduce your risk for many other conditions, including diabetes and heart disease.

Limit alcohol

If you drink, do so in moderation. Studies suggest that having more than two alcoholic drinks a day may increase your breast cancer risk by approximately 25 percent, the ACS says. One drink equals 12 ounces of beer, 4 to 5 ounces of wine or 1-1/2 ounces of hard liquor.

Get moving

Among its many benefits, physical activity has been shown to reduce breast cancer risk, the ACS says. No one knows exactly why, but it may be because of the effects of activity on hormones, energy balance, weight reduction and the immune system.

Researchers aren't sure how much exercise to recommend, or the type of activity. Until researchers know more, aim for at least 30 minutes of moderately intense activity, such as walking, jogging or strength training, on most days of the week, the ACS says.