Although a family history of breast cancer is important in assessing a woman’s risk for invasive breast cancer, other relevant factors should also be considered. This point was driven home by the findings of a recent study, which demonstrated that a significant portion of women who develop invasive breast cancer have no family history of the disease.
In order to characterize the estimated risk of invasive breast cancer in postmenopausal women with no family history of breast cancer, investigators used the National Cancer Institute’s Breast Cancer Risk Assessment Tool (www.cancer.gov/bcrisktool/) to calculate the baseline risk score of 3,991 women taking part in the Continuing Outcomes Relevant to Evista (CORE) trial. They also looked at 1,275 women from the placebo arm of CORE and 5,047 from the placebo arm of the Raloxifene Use for the Heart trial to evaluate incidence rates of invasive breast cancer.
Of the 92 women in the placebo populations who developed invasive breast cancer, 60 (65%) did not have a family history of breast cancer, and had risk scores between 1% and 2%. Nearly half (43%, or 40) of the 92 afflicted women had scores below the high-risk cutoff of 1.66%.
The study, led by Eli Lilly and Company researcher Angelina Sontag, is published online by the journal Menopause.