Breast Cancer Prevention (PDQ®): Prevention - Patient Information [NCI] - Breast Cancer Prevention
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.
Cancer didn't catch Christina Applegate unprepared. Because her mother had battled both breast cancer and ovarian cancer, Applegate had been going for regular mammograms since the age of 30. "But when I turned 36, my doctor said that my breasts were just too dense for mammography alone, and he referred me for screening MRIs at Cedars-Sinai Medical Center," she recalls.
Just a few months before she learned she herself had breast cancer, the actor got a shocking insight into the struggles faced...
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:
Endogenous 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.
Hormone replacement therapy/Hormone therapy
Hormones that are made outside the body, in a laboratory, are called exogenous hormones. Estrogen, progestin, or both may be given to replace the estrogen no longer produced 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) and may be given in one of the following ways:
Combination HRT/HT is estrogen combined with progesterone or progestin. This type of HRT/HT increases the risk of developing 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 getting breast cancer decreases.
Estrogen-only therapy may be given to women who have had a hysterectomy. Clinical trials studying whether estrogen-only therapy affects the risk of breast cancer have had mixed results. In women who have a uterus, estrogen-only therapy increases the risk of uterine cancer.
Radiation therapy to the chest for the treatment of cancers increases the risk of breast cancer, starting 10 years after treatment and lasting for a lifetime. The risk of developing breast cancer depends on the dose of radiation and the age at which it is given. The risk is highest if radiation treatment was used during puberty. For example, radiation therapy used to treat Hodgkin disease by age 16, especially radiation to the chest and neck, increases the risk of breast cancer.