Breast Cancer Risk
Breast cancer risk factors
(adopted from American Cancer Society, (www.cancer.org):
- Things you can’t change:
- Age: Women are more likely to develop breast cancer as they age, with menopausal women more at risk. Eight out of ten breast cancers occur in women over age 50.
- Getting your period early: Age < 12
- Going through menopause later
- Family history and genetics: Approximately 5-10% of breast cancers are genetically linked (so not having a relative with breast cancer doesn’t mean you won’t get it). Women with breast cancer in 2+ individuals on the same side of the family, especially if diagnosed at <50 years old or a triple negative (ER/PR/her-2) breast cancer should discuss this history with their doctor or a genetic counselor.
- Personal history: Women with cancer in one breast have a greater chance of getting a new cancer in the other breast or in another part of the same breast. This is different from a return of the first cancer (called a recurrence).
- Race: White women are slightly more likely to get breast cancer, but African American women are more likely to die from the disease Asian, Hispanic and American Indian women have a lower risk
- Breast biopsy: Some benign biopsy results place women at an increased risk of developing breast cancer, these include atypical ductal hyperplasia and lobular carcinoma in situ.
- Dense breast tissue: Dense breast tissue means there is more gland tissue and less fatty tissue. Women with denser breast tissue have a higher risk of breast cancer. Dense breast tissue can also make it harder for doctors to spot problems on mammograms.
- Things you (maybe) can change:
- Childbearing history and breastfeeding: Women who have never had children or had their first child after age 30 are at greater risk for breast cancer. Breastfeeding children may be associated with a decrease in breast cancer risk, although this effect is likely small.
- Hormone replacement therapy: There may be an increase in breast cancer risk for women on long-term endocrine replacement therapy after menopause.
- Birth control: While long-term use of certain forms of birth control (birth control pills and injections) may be associated with slightly higher incidence of breast cancer, this risk seems to return to normal when birth control is stopped.
- Alcohol: Alcohol use has been linked to increase risk of breast cancer. The American Cancer Society recommends women limit alcohol consumption to no more than one drink a day.
- Obesity and being overweight: Increased body mass index is associated with an increased risk of breast cancer, especially for post-menopausal women.
- Physical activity: Studies show that exercise reduces risk of breast cancer.
- Things we think do not impact risk
- Antiperspirants: A large study compared the underarm hygiene habits of women with breast cancer to a control arm without breast cancer and found no connection between breast cancer risk and using underarm antiperspirants
- Type of bra
- Induced abortions
- Breast implants
- Chemicals: At this time research does not show a clear link between breast cancer risk and exposure to things like plastics, certain cosmetics and personal care products, and pesticides (such as DDE).