The main factors that influence your risk include being a woman and getting older. Most breast cancers are found in women age 50 or older. Some women get breast cancer even without any other risk factors that they know of. A number of breast cancer risk assessment tools have been developed to help people estimate their likelihood of developing breast cancer.
For people with a personal history of breast cancer or a significant family history of breast cancer, other ways to determine their risk of breast cancer may work better. The American Cancer Society (ACS) estimates that a woman's chance of developing breast cancer during her lifetime is about 13 percent. Most breast cancers are sporadic, meaning that they develop from damage to a person's genes that occurs by chance after birth. Many women are concerned about having mammograms as part of the breast exam because it exposes them to X-rays.
Wealthier women from all racial and ethnic groups have a higher risk of developing breast cancer than less wealthy women in the same groups. White women are more likely to develop breast cancer than black women, but among women under 45, the disease is more common in black women than in white women. Women with dense breast tissue have less fat and more breast cells and connective tissue in their breasts. DCIS and LCIS are changes in breast tissue that can develop into breast cancer in some women.
Women who lost 4.4 to 10 pounds had a 13 percent lower risk than women who didn't lose weight, while those who lost 10 to 20 pounds had a 16 percent lower risk and those who lost more than 20 pounds had a 26 percent lower risk of breast cancer, according to a large study published in the Journal of the National Cancer Institute. If you started menstruating before your 12th birthday, you are at greater risk for breast cancer because of the increase in the number of years your breast tissue has been exposed to estrogen. A history of breast cancer also increases your risk, including your own personal history, if you've had it before, and your family history. Having a first pregnancy after age 35, or if you've never had a full-term pregnancy, carries a higher risk of breast cancer.
If the disease has spread beyond the breasts and lymph nodes, surgery is usually not recommended and the main treatment is medical therapy. However, having one or even several risk factors for breast cancer doesn't necessarily mean that you'll develop breast cancer. Women who are overweight after menopause have a higher risk of breast cancer than women who are not overweight.
