Breast cancer is the second-most common cancer of American women, following skin cancer. This disease will result in the death of one in 35 women and occurs in about one in eight women over their lifetime, according to the American Cancer Society. The exact causes of breast cancer are still not entirely clear. Knowledge of the risk factors associated with breast cancer may help women prevent this deadly condition.
Age
Women over the age of 60 are more at risk for breast cancer than younger women. According to the American Cancer Society, hormonal changes that occur with menopause may help to feed breast cancer cells. Older women are also more likely to build up mutations in specific breast cancer genes that can promote the onset of breast tumors.
Sex
While it is possible for men to develop breast cancer, women are 100 times more likely to have breast cancer than men. The American Cancer Society explains that the female sex hormones estrogen and progesterone play a role in promoting breast tumor growth.
Hormone Levels
Lifetime exposure to the female sex hormones progesterone and estrogen have a very important role in breast cancer risk. According to the American Cancer Society, women with longer hormone exposures are more likely to develop breast cancer. This includes women who enter puberty early as well as women who experience menopause relatively late. Because women stop menstruating during pregnancy, women who have had multiple pregnancies have lower lifetime exposure to estrogen and also have a lower risk of developing breast cancer. The National Cancer Institute explains that progesterone hormone replacement therapies given to menopausal women or women who have had a hysterectomy can also increase breast cancer risk.
Obesity
Body fat plays a role in the production of estrogen and can also contribute to breast cancer risk. According to the American Cancer Society, obesity and body fat increase breast cancer risk in women. This risk especially high in older, obese women who continue to produce estrogen from body fat after menopause. While body fat plays a role in breast cancer risk, fat in the diet is still not known to increase breast cancer risk.
Lack of Exercise
The Mayo Clinic suggests that women exercise rigorously at least four times a week to lower breast cancer risk. Consistent exercise can lower estrogen levels and help to prevent breast cancer, especially in pre-menopausal women.
Alcohol Use
Excessive alcohol use also contributes to breast cancer risk. The Mayo Clinic recommends that women limit alcohol intake to one drink per day or less to lower their breast cancer risk.
