A risk factor increases your chances of developing cancer. Modifying the following risk factors may help reduce your risk of breast cancer.

Limit Exposure to Estrogen when Possible

High levels of estrogen have been linked to the development of breast cancer. For older women, the greatest exposure to estrogen is via postmenopausal hormone replacement therapy. You should have a frank conversation with your doctor as to the risks and benefits of hormone replacement therapy relative to breast cancer. Hormone replacement therapy that includes progesterone may have a higher risk of cancer than does estrogen alone.

Other lifestyle factors may also increase your exposure to estrogen. If possible, try to limit these factors:

  • Overweight after the age of menopause
  • Alcohol consumption
  • Physical inactivity

Maintain a Healthful Weight

Excess weight—particularly after menopause—may increase your chances of developing breast cancer. This is due to the fact that after menopause, most of the estrogen in a woman’s body comes from her own fat tissue. The more fat on the body, the higher the degree of estrogen. Risk also appears to increase if you have gained ten pounds or more after age 30.

Additionally, studies have shown that where you gain weight may affect your risk of breast cancer. Women who carry more weight in the abdomen and upper body (resulting in an “apple” shape) have a different hormonal profile than women who carry weight in the lower body (hips, buttocks, and thighs), which results in a “pear” shape. Researchers have found that women who fit the “apple” shape profile may be at higher risk of developing breast cancer, because they have lower levels of sex hormone binding globulin (SHBG), a hormone that binds the body’s circulating estrogen, preventing it from binding to breast tissue.

For more information on achieving and maintaining a healthful weight, click here .

Limit Alcohol Consumption

Studies have shown that women who drink 2–4 alcoholic drinks daily have a 40% greater risk of developing breast cancer than non-drinkers. This may be due to the fact that alcohol may alter the way a woman's body metabolizes estrogen, and may cause blood estrogen levels to rise, increasing the risk of breast cancer onset.

Be Physically Active

Exercise helps maintain weight and modulates high levels of estrogen. It is also believed that low to moderate levels of exercise may enhance the immune system. Studies have shown that women who exercise at least four times per week before the onset of menopause were able to significantly reduce their rate of breast cancer. However, exercise is especially important for women after menopause to prevent increasing weight gain, which, in turn, leads to higher estrogen levels and a greater risk of breast cancer.

Exercise has many benefits and is recommended for overall health as well as reducing the risk of breast cancer.

For more information on starting a regular exercise program, click here .

Don’t Smoke

Smoking greatly increases your risk of several cancers, including breast cancer.

For more information on quitting smoking, click here .

Ask Your Doctor about Hormonal Therapy for the Prevention of Breast Cancer

In some women at high risk for breast cancer, hormonal therapy may be given in an attempt to prevent the development of breast cancer. The drugs used in these cases are tamoxifen and raloxifene.

Tamoxifen (Nolvadex) – in the Breast Cancer Prevention Trial, tamoxifen was shown to reduce breast cancer incidence by 49% in women at increased risk of the disease.

Side effects of tamoxifen include the following:

  • Blood clots
  • Endometrial changes, such as hyperplasia
  • Polyps
  • Endometrial or uterine cancer

Raloxifene (Evista) – in a large study of its use to treat osteoporosis, raloxifene was shown to reduce the incidence of breast cancer. The Multiple Outcomes of Raloxifene Evaluation (MORE), which was a multicenter, randomized, double-blind trial, studied 7,705 postmenopausal women taking raloxifene in two doses or placebo for about 40 months. Among the women in this study who had osteoporosis, the risk of invasive breast cancer was decreased by 76% during 3 years of treatment with raloxifene. Raloxifene has been associated with an increased risk of blood clots.