Using Information on Breast Cancer Growth, Spread, and Detectability to Find the Most Effective Ways for Screening to Reduce Breast Cancer Death

Screening is believed to reduce breast cancer death by finding tumors before they have spread beyond the breast, when they can still be cured by local treatment. Thus, the effectiveness of screening is directly affected by the rates of breast cancer growth and spread and the detectability of breast cancer by screening mammography. During the past few years, my colleagues and I have developed a computer simulation model of breast cancer growth and spread that can calculate such things as the relation between the screening interval and the fraction of women likely to die of breast cancer. A nonmathematical summary of the results of these studies is presented here, which indicates that great reductions in breast cancer death should be achievable by prompt compliance with the annual screening recommendation and that even greater numbers of lives might be saved by screening more frequently than once a year.