The study found that in gen2, the median age of diagnosis was 42, compared to age 47 in gen1. In comparing generations within a family, the median difference was six years. Comparing decades of birth in all born after 1950, gen2 were diagnosed earlier than gen1. When stratified by BRCA1 or 2 mutation, the median age of diagnosis in BRCA1 and BRCA2 positive gen2 women was 42 and 44, respectively, and 43 and 50, respectively in BRCA1 positive and BRCA2 positive gen1 women.

"These findings are certainly concerning and could have implications on the screening and genetic counseling of these women," Litton said. "In BRCA positive women with breast cancer, we actually might be seeing true anticipation - the phenotype or cancer coming out earlier per generation. This suggests more than the mutation could be involved, perhaps lifestyle and environmental factors are also coming into play."

The research reconfirms that women with BRCA mutations should continue to be screened per the guidelines - mammography, MRI and consideration of prophylactic surgeries - yet perhaps with increased suspicion and even at an earlier age, said Litton, who notes that the addition of MRI screening may account for some of the change in diagnosis seen in the study.

Further analysis is needed given the relatively small number of women in the cohort and the possibility of recall bias, as the gen2 women were providing their family histories, Litton explained. As follow up study, Litton plans to look into biological basis for potential earlier diagnosis.

Source: University of Texas M. D. Anderson Cancer Center