Reference summary — not medical advice or a personal risk estimate.
Inherited BRCA1/BRCA2 gene mutations
Quick answer
Not IARC-classified — this is not a chemical or physical agent IARC rates. Recognized as a cancer risk factor based on sufficient evidence in humans. Inherited. Passed down from a parent; can be identified through genetic testing, typically pursued after genetic counseling for people with relevant personal or family history.
Summary
Inheriting a harmful BRCA1 or BRCA2 gene variant substantially increases lifetime risk of breast, ovarian, and several other cancers, and is associated with cancers occurring at younger ages.
Detail
BRCA1 and BRCA2 are genes involved in DNA repair. NCI reports that people who inherit a harmful variant in either gene face significantly increased lifetime risk of breast and ovarian cancer, along with elevated risk of prostate, pancreatic, and other cancers, and that these cancers tend to occur at younger ages than in the general population. Genetic counseling and testing are available for people with a strong personal or family cancer history; a positive result does not mean cancer is certain.
What's not established
A harmful BRCA1/BRCA2 variant substantially raises risk but does not make cancer certain, and the exact lifetime risk percentage varies by study, specific variant, and other individual factors. This entry does not establish your personal risk and is not a substitute for genetic counseling.
Evidence sources
Every claim on this page traces back to one of these. Click through to read the primary document yourself.
Primary sources
NCI
NCI — BRCA Gene Changes: Cancer Risk and Genetic Testing
Last reviewed: October 2026
Official reference list
A government list some readers use alongside the primary evidence. Meyron is not affiliated with it. A chemical being listed does not by itself describe a risk from any particular product.
- California Prop 65 list
State of California's list of chemicals known to cause cancer or reproductive harm.