Data on lesser known variants didn't improve powers of standard risk model
WEDNESDAY, March 17 (HealthDay News) -- Plugging certain genetic data into the standard risk-assessment model for breast cancer won't do much to help gauge a woman's odds for getting the disease, a new study shows.
Assessing a woman's breast cancer risk remains a work in progress for doctors. For years, experts have relied on what's known as the "Gail model," which asks women seven questions related to family history, medical history and other areas, and then predicts her risk for breast cancer.
Experts have also known that women with mutations in the BRCA1 and BRCA2 genes are at much higher breast cancer risk than women without these mutations.
But more recently, scientists have identified several other genetic variants linked with breast cancer.
So, in a study published in the March 18 issue of the New England Journal of Medicine, researchers decided to add these newer variants to the model and see if it could improve prediction of risk over and above the standard Gail model.
"These variants are common," noted study co-author Dr. Patricia Hartge, senior scientist and deputy director of epidemiology and biostatistics at the U.S. National Cancer Institute. The variants are known as SNPs -- single nucleotide polymorphisms.
They're not as powerful, however, as the much-cited BRCA1 and BRCA2 gene mutations, Hartge said, and each SNP boosts a woman's risk much less than the BRCA genes might.
In the study, Hartge and her colleagues evaluated information on both traditional risk factors -- such as those assessed by the Gail model and 10 common SNP genetic variants, deriving information and genetic data from four large U.S.-based studies and one large Polish breast cancer study. Women in the studies ranged in age from 50 to 79.
In all, almost 5,600 women from the studies had breast cance
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