Optimal Guidelines for Screening Mammography Based on Individual Risk Factors

Abstract

Early diagnosis is effective in reducing the death rate and treatment costs due to breast cancer. Although there is consensus that mammograms are effective for early diagnosis, not all organizations agree upon screening guidelines. Current guidelines from the American Cancer Society recommend an annual mammography starting at age 40. In contrast, the public health system in Chile guarantees two screening mammograms between the ages of 50 and 54. The objective of this paper is to study optimal individualized mammography guidelines that enable dynamic tracking of patients’ risk factors, from the perspective of the public health system. We develop a stochastic dynamic programming model to minimize the total expected lifetime cost, including screening and treatment. The optimal number of screening mammograms derived from our model falls between the American Cancer Society and Chilean recommendations. However, when addressing the average breast-cancer risk, the optimal screening policy is either too aggressive for low-risk women or too conservative for high-risk women. Our results also show that it is beneficial to segment the population based on risk levels and to develop screening guidelines accordingly. Finally, sensitivity analysis indicates that optimal policies are sensitive to the costs of mammogram and treatments. This might explain why different countries have such a difference in screening polices. Thus, importing successful guidelines from other countries should not be recommended due to differences in costs of equipment and labor, and also in population genetics, lifestyles and environments.