Risk factors for
breast cancer
Having a risk factor does not mean you will get the disease, and not all risk factors have the same effect. Most women have some risk factors, but most women do not get breast cancer. If you have breast cancer risk factors, talk with your doctor about ways you can lower your risk and about screening for breast cancer. Risk factors include:
Increasing age
The risk for breast cancer increases with age; most breast cancers are diagnosed after age 50.
Menstrual history
Women who start their periods before age 12 are exposed to hormones longer, raising the risk for breast cancer.
Starting menopause after age 55
Being exposed to oestrogen hormones for a longer time later in life raises the risk of breast cancer.
Overweight and obesity
Women who are overweight or obese have a higher risk of getting breast cancer than those at a normal weight, this is especially true for women post-menopause.
Combination hormone therapy
Taking hormones to replace missing oestrogen and progesterone in menopause for more than five years raises the risk for breast cancer.
Radiation therapy
Women who had radiation therapy to the chest or before age 30 have a higher risk of getting breast cancer later in life.
Alcohol consumption
Research consistently shows that drinking alcoholic beverages increases a woman’s risk of breast cancer.
History of breast cancer
Women who have had breast cancer are more likely to get breast cancer a second time.
Late or no pregnancy
Having the first pregnancy after age 30 and never having a full-term pregnancy can raise breast cancer risk.
Genetic mutations
Approximately 5% to 10% of breast cancers are thought to be hereditary, caused by abnormal genes passed from parent to child.
Sedentary lifestyle
Women who are not physically active have a higher risk of getting breast cancer.
Race/Ethnicity
White women are slightly more likely to develop breast cancer than Black, Hispanic, and Asian women. But Black women are more likely to develop more aggressive, more advanced-stage breast cancer that is diagnosed at a young age.
Oral contraceptives
Certain forms of oral contraceptive pills have been found to raise breast cancer risk.
Family history of 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 cancer.
Having dense breasts
Dense breasts have more connective tissue than fatty tissue, which can sometimes make it hard to see tumors on a mammogram.
