When BRCA Mutations Run in the Family, Should Noncarriers Worry?

A key rationale of BRCA mutation testing is to guide counseling and recommendations for family members of women with breast cancer who test positive. Some studies have suggested that relatives of women who carry deleterious BRCA mutations but who themselves test negative are at excess risk for breast and ovarian cancer; however, other findings conflict. Investigators used data from population-based cancer registries in Australia, Canada, and Northern California to assess breast cancer risk in first-degree relatives (FDRs) of women with the disease. Registry participants with breast cancer were tested for BRCA1 and BRCA2 mutations; FDRs of identified mutation carriers also were tested (FDRs of women with breast cancer who tested negative for…