Breast Cancer Risk Factors
Risk is not a prediction. It is a way of deciding how closely to watch and when to start screening.
Medically reviewed by Charles Ortega, PA-C, MPAS · Last reviewed October 1, 2026 · Educational information, not medical advice. Innovare Tx does not perform mammograms.
How common breast cancer is
The American Cancer Society puts the average lifetime risk for a woman in the United States at about 1 in 8, or roughly 13%. The median age at diagnosis is 63, and about 1 in 10 women diagnosed are younger than 45.
The same organization reports that death rates from breast cancer fell 44% between 1989 and 2023, which it says is most likely the result of finding breast cancer earlier through screening and increased awareness, as well as better treatments.
Risk factors you cannot change
These are the factors the CDC lists that are outside your control:
- Getting older. Risk rises with age, and most breast cancers are diagnosed after age 50.
- Inherited gene changes, such as in BRCA1 and BRCA2, which raise the risk of breast and ovarian cancer.
- Reproductive history. Starting periods early or reaching menopause late means longer exposure to hormones.
- Dense breasts, which also make cancers harder to see on a mammogram.
- A personal history of breast cancer or of certain noncancerous breast diseases.
- A family history of breast or ovarian cancer.
- Radiation therapy to the chest or breasts before age 30.
- Exposure to the drug diethylstilbestrol (DES).
Risk factors you can change
The CDC also lists factors that are within reach:
- Not being physically active.
- Being overweight or having obesity after menopause.
- Taking hormone replacement therapy that combines estrogen and progesterone.
- Reproductive history, such as a first pregnancy after age 30, not breastfeeding, or never having a full-term pregnancy.
- Drinking alcohol. Risk increases with the amount a woman drinks.
None of these settles the question in either direction. They are reasons to look at the whole picture with your provider, and some of them, such as activity and weight, are things we work on in primary care anyway. If weight is part of your picture, see our weight management service.
What a family history does and does not mean
According to the American Cancer Society, having one first-degree relative (a mother, sister or daughter) with breast cancer almost doubles a woman's risk, and two first-degree relatives raise it about three-fold.
The other half of that picture matters just as much. Only up to about 10% of breast cancers are thought to be hereditary, which means most people who are diagnosed have no known inherited cause. No family history is not a reason to skip screening.
If breast, ovarian, tubal or peritoneal cancer runs in your family, the U.S. Preventive Services Task Force recommends that a primary care clinician assess your history with a brief risk tool and, when the result is positive, refer you for genetic counseling. See high-risk screening.
What to do with this
Bring your family history to your next visit: who was diagnosed, with what, and at roughly what age, on both your mother's and your father's side. That one conversation decides whether the standard screening schedule fits you or whether you should start earlier.
Frequently asked questions
Next in the breast health hub
High-Risk Breast Cancer Screening
Who is high risk, how it is assessed, and how screening changes.
ReadBreast Cancer Screening Guidelines by Age
USPSTF, ACS, ACOG and ACR side by side, and how to choose between them.
ReadBreast Cancer Myths and Facts
Antiperspirants, bras, radiation and family history: what the evidence says.
ReadReady to get your screening arranged?
Book a visit at our Addison clinic. We review your risk, help you arrange a mammogram at an imaging center, and go over the results with you.