Age is the most important factor. As you get older, your risk of getting breast cancer increases.
* From birth to age 39, 1 woman in 231 will get breast cancer (<0.5% risk).
* From ages 40–59, the chance is 1 in 25 (4% risk).
* From ages 60–79, the chance is 1 in 15 (nearly 7%).
Assuming that you live to 90, the chance of getting breast cancer over the course of an entire lifetime, is one in 8 (an overall lifetime risk of 12.5%).
Risk increases with age, because the wear and tear of living increases the chance that a genetic abnormality, or “mistake,” will develop in cells that your body doesn't find and fix.
Genetic predisposition. Women with BRCA1 or BRCA2 genes have a higher risk of breast than other women
Menstrual history. Women who begin menstruating at an early age (before 12) and women who reach menopause after age 50 have an increased risk of breast cancer.
Delayed childbirth. Women who have their first child after 30 or who have never had a child are at a higher risk for breast cancer.
Personal history. Women who have had cancer in one breast are three to four times more likely to develop breast cancer in the other breast than those women who have never had breast cancer.
Family history. Having a first degree relative (i.e.: mother, sister, daughter) with breast cancer can double a woman’s risk of developing breast cancer.
Alcohol consumption. Drinking on a daily basis can increase a woman’s risk for developing breast cancer. Women who drink 4-5 alcoholic beverages a day were found to have a 41% increase in risk factor for developing invasive breast cancer, compared to women who do not drink alcohol.
Smoking. Smoking is known to increase the risk of several types of cancer, including breast cancer.
Diet. Diets high in fats, especially polysaturated fats, hydrogenated fats, and transfatty acids, increase one’s risk of developing breast cancer.
Weight. New studies are showing that women who have gained excess weight as adults are at greater risk of developing breats cancer. Women who have been heavy all their lives are not at an increased risk of developing breast cancer.
Previous radiation therapy. Women who have had previous radiation therapy (e.g.: for lymphoma) are at increased risk. This is especially true for women who underwent radiation therapy at an earlier age.