BRCA Mutations May Cause More Cancers Than Thought
BRCA1 and BRCA2 mutations could affect more people than previously reported
TUESDAY, Dec. 5 (HealthDay News) -- More people in the general population may be carriers of BRCA1 and BRCA2 mutations than thought, and the mutations may play a role in testicular and pancreatic cancers in addition to ovarian and breast cancers, researchers report in the Dec. 6 issue of the Journal of the National Cancer Institute.
Harvey A. Risch, M.D., Ph.D., of the Yale University School of Medicine in New Haven, Conn., and colleagues searched for mutations in 1,171 ovarian cancer patients in Ontario and analyzed cancer outcomes in 8,680 of the patients' first-degree relatives. They used the results and cancer outcomes in the general population to estimate BRCA carrier status.
The investigators found that 75 of the 977 patients with invasive ovarian cancer had BRCA1 mutations and 54 had BRCA2 mutations, for total mutation frequency of 13.2 percent. In the general Ontario population, they estimated that mutation frequency is 0.32 percent for BRCA1and 0.69 percent for BRCA2. Compared to non-carriers, BRCA1 carriers had higher risks of ovarian (relative risk, 21), female breast (RR, 11) and testicular (RR, 17) cancers and that BRCA2 carriers had higher risks of ovarian (RR, 7.0), female and male breast (RR, 4.6 and 102, respectively) and pancreatic (RR, 6.6) cancers.
"Although penetrance estimates continue to vary between studies, BRCA mutation status remains one of the strongest markers for risk of this disease, warranting increased surveillance with such modalities as magnetic resonance imaging, hormonal and other chemoprevention, and, in selected circumstances, preventive surgery," concludes the author of an accompanying editorial.