Most patients who develop breast cancer do not have any risk factors other than being a woman and getting older.
Dr. Wendie Berg, FACR
Chief Scientific Advisor, DenseBreast-Info.org; Professor of Radiology, University of Pittsburgh School of Medicine
Some women are at high risk because of a known disease-causing mutation, most commonly in BRCA1 or BRCA2. Such mutations are more common in women of Ashkenazi Jewish descent and Black women.
Prior radiation therapy to the chest before age 30, and at least eight years earlier, also creates a high risk for breast cancer, as does a personal history of breast cancer. Women at high risk are recommended to have annual screening with MRI and to add mammography after age 30.
Combinations of other risk factors may also put a woman at high risk. Factors to be considered include:
- Family history of breast cancer, especially if diagnosis was before age 50 or in multiple relatives on the same side of the family
- Prior breast biopsies, especially atypical biopsies
- High body mass index (BMI over 25) after menopause
- Combination estrogen and progesterone hormone supplements
- Dense breasts (heterogeneously dense or extremely dense) on a mammogram report.
Formal risk assessment should be done by age 25 and then every few years if new family history or other risks develop. A lifetime risk of 20% or more is considered “high risk.” Over 20% of women in their 40s are at high risk, but fewer than 1% of women in their 70s are at high risk, and screening MRI is not usually recommended beyond age 70.
