Cancers associated with BRCA1 and BRCA2 mutations other than breast and ovarian.
Level 3 - non-randomized controlled study
Retrospective cohort study comparing cancer incidence in mutation carriers to general population rates using standardized incidence ratios.
PubMed 25224030 · doi:10.1002/cncr.29041
What was done
Researchers identified 1,072 patients who received genetic counseling at a single institution and tested positive for a deleterious BRCA1 or BRCA2 mutation. Expected cancer cases were derived from general population cancer incidence rates in 5-year age intervals, and standardized incidence ratios (SIRs) were calculated to assess non-breast and non-ovarian cancer risks.
What was found
Among the 1,072 carriers, 1,177 cancers across 30 types were documented. BRCA1 mutation carriers showed no statistically significant increase in cancers other than breast and ovarian cancer, though a trend in melanoma was observed (exact numbers not reported in the abstract). BRCA2 carriers had a significantly higher incidence of pancreatic cancer in both men and women (SIR, 21.7; 95% CI, 13.1-34.0; P < .001) and prostate cancer in men (SIR, 4.9; 95% CI, 2.0-10.1; P = .002).
Why it matters
This study provides quantitative evidence supporting guidelines that recommend enhanced surveillance for pancreatic and prostate cancers specifically in individuals harboring BRCA2 mutations.
Limits
The study is based on a single-institution genetic counseling cohort, introducing potential ascertainment and referral biases. The abstract does not provide exact point estimates or confidence intervals for BRCA1-related cancer risks or other specific secondary cancer sites.
Cited by
- supports BRCA mutations predispose individuals to breast cancer and other forms of cancer.