The aim of this study was to evaluate the practical usefulness of family history as a tool for breast cancer risk assessment.
Women from the Raloxifene Use for The Heart trial (N = 10,048), which consisted of postmenopausal women with or at high risk for coronary artery disease, were included in this post hoc analysis. The breast cancer risk score at baseline was calculated using the National Cancer Institute's Breast Cancer Risk Assessment tool. The positive predictive value of family history as a predictor of risk was determined for several risk thresholds.
Almost all (99.6%) women with a family history of breast cancer are found to be at high risk using the National Cancer Institute's accepted cutoff point of at least 1.66%, and almost 98% of women with a family history of breast cancer belong to the high-risk group when the cutoff point for risk score is 2%.
Family history alone as a high-risk predictor is associated with a high positive predictive value at commonly used cutoff points based on the risk estimates from the traditional Gail model. Although more complex models of breast cancer risk should still be used as the standard for assessment, screening using family history seems to be a first step in beginning the discussion with women.
Using family history as an initial screening tool to assist in identifying those at an increased risk of breast cancer is a good method compared with more complex algorithms. Such simplified screening may thus further the ability to effectively identify and counsel those at risk.
From the 1Department of Obstetrics and Gynecology, University of Missouri-Kansas City, Kansas City, MO; 2US Statistics, Lilly USA, LLC, Indianapolis, IN; and 3Women's Health and Reproductive Medicine, Lilly USA, LLC, Indianapolis, IN.
Received August 26, 2010; revised and accepted October 19, 2010.
Funding/support: This study was supported by Eli Lilly & Company.
Financial disclosure/conflicts of interest: D. Muram and X. Ni are full-time employees and stock holders of Lilly USA, LLC. Dr. Smith has no conflict of interest to declare.
Clinical Trials Registration: NCT00190593.
Address correspondence to: Roger P. Smith, MD, Department of Obstetrics and Gynecology, University of Missouri-Kansas City, Truman Medical Center, 2801 Holmes Street, Kansas City, MO 64108. E-mail: BGumAlley@earthlink.net