BACKGROUND: Comprehensive analyses have shown that screening for cancer
usually induces net costs. In this study, the possible costs and savings
of endoscopic colorectal cancer screening are explored to investigate
whether the induced savings may compensate for the costs of screening.
METHODS: A simulation model for evaluation of colorectal cancer screening,
MISCAN-COLON, is used to predict costs and savings for the U.S.
population, assuming that screening is performed during a period of 30
years. Plausible baseline parameter values of epidemiology, natural
history, screening test characteristics, and unit costs are based on
available data and expert opinion. Important parameters are varied to
extreme but plausible values. RESULTS: Given the expert opinion-based
assumptions, a program based on every 5-year sigmoidoscopy screenings
could result in a net savings of direct health care costs due to
prevention of cancer treatment costs that compensate for the costs of
screening, diagnostic follow-up, and surveillance. This result persists
when costs and health effects are discounted at 3%. The "break-even"
point, the time required before savings exceed costs, is 35 years for a
screening program that terminates after 30 years and 44 years for a
screening program that continues on indefinitely. However, net savings
increase or turn into net costs when alternative assumptions about natural
history of colorectal cancer, costs of screening, surveillance, and
diagnostics are considered. CONCLUSIONS: Given the present, limited
knowledge of the disease process of colorectal cancer, test
characteristics, and costs, it may well be that the induced savings by
endoscopic colorectal cancer screening completely compensate for the
costs
