Breast Cancer Risk Factors

Having a risk factor, or even many risk factors, does not mean that you are sure to get the disease. It may only increase your odds. You can’t change some of the factors associated with breast cancer, but there are some lifestyle choices you can control.

Established risk factors that cannot be changed:

• Being a Woman - Men can get breast cancer, too, but this disease is about 100 times more common in women than in men.
• Age - Your risk of breast cancer goes up as you get older. About two out of three invasive breast cancers are found in women 55 or older.
• Family History - Most women (less than 15 percent) who get breast cancer do not have a family history of the disease. Having a close blood relative with breast cancer almost doubles your risk. Having two first-degree relatives increases your risk about threefold.
• Genetics - The most common cause of hereditary breast cancer is an inherited mutation in the BRCA1 or BRCA2 gene. (Genetic testing can be helpful in some cases. However, not every woman needs to be tested and the pros and cons need to be considered carefully.)
• Personal History of Breast Cancer - Having breast cancer makes you three to four times more likely to develop a new cancer in the other breast or a different part of the same breast. This risk is different from the risk of the original cancer coming back (called risk of recurrence). Although this risk is low overall, it's higher for younger women with breast cancer.
• Having dense breast tissue - Women with dense breasts have a risk of breast cancer that is about 1.5 to 2 times that of women with average breast density. Unfortunately, dense breast tissue can also make it harder to see cancers on mammograms.
• Race/Ethnicity - White women are slightly more likely to develop breast cancer during their lifetimes than African-American, Hispanic, Native American and Asian women. But in women younger than age 45, breast cancer is more common in African-American women, and the cancer is more likely to be aggressive, advanced-stage breast cancer.
• Menstruation beginning and end - Women who started menstruating early (especially before age 12) have a slightly higher risk of breast cancer. And women who go through menopause later (after age 55) have a slightly higher risk of breast cancer.
• Having radiation to your chest - Radiation therapy to the chest for another cancer (such as Hodgkin’s disease or nonHodgkin’s lymphoma) increases the risk for breast cancer. Radiation to the face to treat adolescent acne (something that’s no longer done), puts women at higher risk of developing breast cancer later in life.
• Exposure to diethylstilbestrol (DES) - From the 1940s through the early 1970s some pregnant women were given an estrogen-like drug called DES because it was thought to lower their chances of losing the baby (miscarriage). These women have a slightly increased risk of developing breast cancer, as well as women whose mothers took DES during pregnancy.

Lifestyle-related risk factors that can be changed

Certain breast cancer risk factors are related to personal behaviors or lifestyle choices.

• Using hormone therapy - Hormone therapy has been used for many years to help relieve symptoms of menopause and help prevent osteoporosis (thinning of the bones). Talk with your doctor about the risks of different types of hormone therapy.
• Smoking - Smoking is linked to a higher risk of breast cancer in younger, premenopausal women. There may also be a link between very heavy secondhand smoke exposure and breast cancer risk in postmenopausal women.
• Drinking alcohol - Drinking alcoholic beverages -- beer, wine or liquor -- is linked to an increased risk of hormone-receptor-positive breast cancer. The risk increases with the amount of alcohol you consume.
• Lack of exercise - Exercising regularly at a moderate or intense level can help lower risk of breast cancer, especially if you are past menopause.
• Being overweight or obese - Overweight or obese women have a higher risk of being diagnosed with breast cancer than women who maintain a healthy weight, especially after menopause. If you have been diagnosed and treated for breast cancer, being overweight can increase your risk of breast cancer coming back.
• Birth control - When thinking about using hormonal birth control, you should discuss this and other risk factors for breast cancer with your doctor.