Cost-effectiveness of aspirin, celecoxib, and calcium chemoprevention for colorectal cancer.

BACKGROUND Studies have indicated that aspirin chemoprevention may be effective in preventing colorectal cancer within the general population, and aspirin, celecoxib, and calcium may be effective in preventing adenomas within those people who have previously undergone polypectomy. OBJECTIVE To assess the cost-effectiveness of aspirin, celecoxib, and calcium chemoprevention in the context of the fecal occult blood test screening program. METHODS An existing state transition model developed to assess colorectal cancer screening options was modified to incorporate the costs and outcomes associated with chemoprevention. Relative risks of disease progression were incorporated based on the effectiveness of the chemopreventive agents. Additional benefits and harms associated with chemoprevention were included. Sensitivity analyses were undertaken. RESULTS Aspirin chemoprevention plus screening within the general population aged 50 to 60 years is estimated to cost £23,000 per quality-adjusted life year (QALY) gained compared with screening alone (based on 2008 prices). For individuals who have undergone polypectomy, calcium is estimated to cost between £8000 and £30,000 per QALY gained depending on the starting and stopping age of the chemoprevention policy. Based on current evidence, calcium has a higher probability than aspirin of providing value for money within this population, although the long-term benefits and harms are subject to considerable uncertainty. Celecoxib chemoprevention is unlikely to be considered to be cost-effective. CONCLUSION Calcium chemoprevention is likely to be a cost-effective option for individuals who have undergone polypectomy. Further research is required to assess the long-term benefits and harms of calcium compared with aspirin chemoprevention. Chemoprevention appears less economically attractive within the general population.