Limited Family Tree Affects Breast Cancer Risk Assessment

In women with deleterious BRCA gene mutations, the risk for developing new primary breast or ovarian cancer within 10 years of the original diagnosis is as high as 40% and 12%, respectively. Genetic screening is based on various risk-assessment models that include family history as a factor. To evaluate the effect of family history on the performance of three common risk-assessment models, investigators studied 306 women (20% of Ashkenazi Jewish descent) with breast cancer diagnosed before age 50 who did not have a family history of breast or ovarian cancer and who were tested for BRCA mutations. Half of these women had limited family structure (i.e., fewer than 2 first- or second-degree female relatives surviving past age 45 in either line…