Projecting individualized probabilities of developing breast cancer for white females who are being examined annually

A model was developed to estimate the probability that a woman at a given age and with specific risk factors will develop breast cancer within a specific interval. The risk factors used were age at menarche, age at first childbirth, number of previous biopsies and number of first-degree relatives with breast cancer. Case-control data from the Breast Cancer Detection Demonstration Project was used to build the model. A proportional hazards model was used with a different baseline hazard rate for women above and below the age of 50, and two-factor interactions between risk variables were also included.