The risk for breast cancer increases with age, most breast cancers are diagnosed after
age 50.
Inherited changes (mutations) to certain genes, such as BRCA1 and BRCA2. Women who have
inherited these genetic changes are at higher risk of breast and ovarian cancer.
Early menstrual periods before age 12 and starting menopause after age 55 expose women
to hormones longer, raising their risk of getting breast cancer.
Dense breasts have more connective tissue than fatty tissue, which can sometimes make it
hard to see tumors on a mammogram. Women with dense breasts are more likely to get
breast cancer.
Women who have had breast cancer are more likely to get breast cancer a second time.
Some non-cancerous breast diseases such as atypical hyperplasia or lobular carcinoma in
situ are associated with a higher risk of getting breast cancer.
A woman’s risk for breast cancer is higher if she has a mother, sister, or daughter
(first-degree relative) or multiple family members on either her mother’s or father’s
side of the family who have had breast or ovarian cancer. Having a first-degree male
relative with breast cancer also raises a woman’s risk.
Women who had radiation therapy to the chest or breasts (for instance, treatment of
Hodgkin’s lymphoma) before age 30 have a higher risk of getting breast cancer later in
life.
DES is a drug that was given to some pregnant women in the United States between 1940
and 1971 to prevent miscarriage, have a higher risk. Women whose mothers took DES while
pregnant with them are also at risk.
Risk factors that can be changed
Women who are not physically active have a higher risk of getting breast cancer.
Older women who are overweight or obese have a higher risk of getting breast cancer than
those at a normal weight.
Some forms of hormone replacement therapy (those that include both estrogen and
progesterone) taken during menopause can raise risk for breast cancer when taken for
more than five years. Certain oral contraceptives (birth control pills) also have been
found to raise breast cancer risk.
Having the first pregnancy after age 30, not breastfeeding, and never having a full-term
pregnancy can raise breast cancer risk.
Studies show that a woman’s risk for breast cancer increases with the more alcohol she
drinks.
Measures to reduce the risk of cancer
Keep a healthy weight.
Exercise regularly.
Don’t drink alcohol, or limit alcoholic drinks.
If you are taking, or have been told to take, hormone
replacement therapyexternal icon or oral contraceptivesexternal icon (birth control
pills), ask your doctor about the risks and find out if it is right for you.
Breastfeed your children, if possible.
If you have a family history of breast cancer or inherited
changes in your BRCA1 and BRCA2
genes, talk to your doctor about other ways to lower your risk.