MONDAY, Sept. 12 (HealthDay News) -- Women with the genetic BRCA mutations, known to be at higher risk of developing breast and ovarian cancers, are being diagnosed with those cancers earlier than previous generations, researchers now report.
''We found with some mathematical modeling about a 7.9-year difference between older and newer [generations]," said Dr. Jennifer Litton, a breast medical oncologist at the University of Texas M.D. Anderson Cancer Center in Houston.
In the study, Litton analyzed the age at diagnosis of two generations of families in which there were BRCA-related cancers. Her research included 132 women diagnosed with a BRCA-positive breast cancer, 106 of whom had a family member of an earlier generation who had also been diagnosed with a BRCA-related breast or ovarian cancer.
In the analysis, the median age for the older generation at diagnosis was 48 (half older, half younger). The median age for the younger generation was 42. And, in a parametric model, the estimated change in the expected age at onset for the entire cohort was 7.9 years, the study showed.
A number of factors could explain the earlier onset, Litton said. Experts talk about a phenomenon in inherited diseases known as anticipation. It refers to diseases occurring at younger ages or with increased severity with each generation. This is due to DNA instability in which the genes actually evolve and change.
Other factors may also help explain the earlier onset, Litton added. Among them, better screening and finding cancers at earlier stages.
"It's important to continue to follow this [research] forward and validate it in bigger studies with more women involved," added Litton, whose research is published in the Sept. 12 online edition of the journal Cancer.
For now, the finding validates the recommendation of the National Comprehensive Cancer Network that
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