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

This was a case-control study including 2852 white women whose breast cancers were detected on screening in the Breast Cancer Demonstration Project in the USA and 3136 matched controls. The objective was to predict the risk of breast cancer in women attending an annual programme of mammographic screening. The main factors emerging were age, age at menarche, age at first live birth, number of previous breast biopsies and a history of breast cancer in a first-degree relative. The relative risks for each factor alone in combination were used to construct a table from which an individual woman undergoing regular mammographic screening can be informed about her probable risk of developing breast cancer at 10, 20 and 30 years and be counselled on what action she might wish to take.