Abstract
A model of breast cancer is developed that consists of hypotheses about the age-specific incidence of the disease, the rate of disease progression, the tendency of the disease to be detected without benefit of regularly scheduled screening examinations, and prognosis related to the extent of disease at treatment. Parameters for the model are estimated from published data. The model is validated by comparing model predictions to data not used in parameterization. The model, under a variety of assumptions, is then used to analyze questions of interest about breast cancer screening strategies. These include the following: the benefits from screening with mammography and clinical examination as a function of the frequency and starting age of screening, the effect of different assumptions about radiation risks on the benefits of screening, the benefits from screening with mammography if yearly clinical examinations are performed, and the benefits from screening with mammography and clinical examination if self-examinations are performed.