There are two kinds of risk factors that increase your chance of developing breast cancer: those you cannot change and those you can affect.
Risk factors you cannot change:
- Being a woman: Though men can get breast cancer, too, it is about 100 times more common in women than men.
- Menstrual periods: Women who begin menstruating before age 12 or those who go through menopause after age 55 have an increased risk for breast cancer.
- Family history: Five to 10 percent of women with breast cancer have a family history of the disease. Having a mother, sister or daughter with breast cancer nearly doubles your breast cancer risk. Having two of those relatives with breast cancer triples the risk.
- Aging: As you age, your risk of developing breast cancer increases, too.
- Dense breast tissue: Dense breasts have less fatty tissue and more fibrous tissue and glandular tissue, which can obscure cancer.
- Diethylstilbestrol exposure: DES was an estrogen-like drug given to women in the 1940s through early 1970s. DES was believed to lower chances of miscarriage. If you took DES while pregnant, your risk of developing breast cancer increases about 30 percent.
Risk factors you can control:
- Oral contraceptive use: Women who take birth control pills marginally increase their risk for breast cancer. Women who stopped using birth control pills more than 10 years ago do not appear to have an increased breast cancer risk.
- Childbirth: Women who have not had children or those who had their first child after age 30 experience a somewhat higher breast cancer risk.
- Hormone therapy after menopause: Talk to your doctor to understand the risks and benefits of hormone replacement therapy.
- Alcohol: Women who drink one alcoholic beverage daily have an extremely small increased risk for breast cancer. Those who consume two to five drinks every day increase their risk by 150 percent. Excessive alcohol consumption is known to increase the risk of developing other cancers, as well.
- Physical activity: Studies have shown that exercise reduces the risk for breast cancer, although we are unsure how much exercise is needed for risk reduction. The American Cancer Society recommends 150 minutes of moderate intensity or 75 minutes of vigorous intensity exercise — or a combination of these — each week.
- Being overweight or obese: The connection between weight and breast cancer risk is complex. Risk appears to increase for women who gain weight as an adult but may not increase among those who have been overweight since childhood. Also, additional fat in the waist area may affect risk more than the same volume of fat in the hips and thighs.
Talk to your physician about your breast cancer risks.