Validating and Improving Models for Projecting the Absolute Risk of Breast Cancer

Abstract
In this issue of the Journal, Rockhill et al. (1) use data from 1992 to 1997 from white women in the Nurses' Health Study (NHS) to address the validity and uses of the model of Gail et al. (2) for estimating breast cancer risk. One issue is how well the model predicts the risk of invasive breast cancer in various subgroups of women (“calibration”). A second issue is how sharply the model discriminates women who will develop breast cancer from those who will not (“discriminatory accuracy”). Rockhill et al. also comment on applications of the model.