The impact of detection and treatment on lifetime medical costs for patients with precancerous polyps and colorectal cancer.

Understanding the costs associated with early detection of disease is important for determining the fiscal implications of government-funded screening programs. We estimate the lifetime medical costs for patients with screen-detected versus undetected polyps and early-stage colorectal cancer. Typically, cost-effectiveness studies of screening account only for the direct costs of screening and cancer care. Our estimates include costs for unrelated conditions. We applied the Kaplan-Meier Smoothing Estimator to estimate lifetime costs for beneficiaries with screen-detected polyps and cancer. Phase-specific costs and survival probabilities were calculated from the Surveillance, Epidemiology, and End Results-Medicare database for Medicare beneficiaries aged >or=65. We estimate costs from the point of detection onward; therefore, our results do not include the costs associated with screening. We used a modified version of the model to estimate what lifetime costs for these patients would have been if the polyps or cancer remained undetected, based on assumptions about the 'lead time' for polyps and early-stage cancer. For younger patients, polyp removal is cost saving. Treatment of early-stage cancer is cost increasing. (c) 2009 John Wiley & Sons, Ltd.