Breast Cancer Risk Factors

Breast cancer is the most common cancer among American women. Approximately one in eight women living in the U.S. will be diagnosed with breast cancer during their lifetime. More than 232,000 U.S. women and 2,200 men are expected to be diagnosed with breast cancer in 2013, according to the National Cancer Institute. Age is the strongest risk factor for breast cancer, but others are significant as well.

General

Age: Your risk of developing breast cancer increases as you get older, and half of all breast cancers are diagnosed in women older than 60.
Gender: A woman is 200 times more likely than a man to develop breast cancer.
Reproductive and menstrual history: Women who have never had a full-term pregnancy or who had their first after age 30 are at higher risk. Women who started menstruating before age 12 or who went through menopause after 55 are also at increased risk.

Lifestyle

Obesity: Being overweight increases your risk of breast cancer, and obese women who are treated for breast cancer are cured less often than non-obese women.
Alcohol: Alcohol use is associated with a slightly higher risk of developing breast cancer.
Inactivity: Women with a long-term history of physical inactivity are at increased risk.

Genetics

Family history: Having a close blood relative such as a mother or sister who has had breast or ovarian cancer can increase your risk.
Personal history: Women who have had breast cancer have a slightly greater chance of developing another breast cancer.
Inherited factors: In some families, genetic mutations may make some women more susceptible to developing breast cancer. The most comment inherited causes are mutations in the BRCA1 and BRCA2 genes.

Previous treatments

Radiation therapy: Women who have had radiation to the chest area, particularly before age 30, may be at a higher risk of developing breast cancer.
Hormone therapy: Menopause hormone therapy combining estrogen and progesterone for more than five years is associated with an increased risk.