Cost-Effectiveness of Earlier or More Intensive Colorectal Cancer Screening in Overweight and Obese Patients.

Background & Aims: Overweight and obese persons have not only elevated rates of colorectal cancer (CRC), but also higher competing mortality and healthcare spending. We examined the cost-effectiveness of intensified CRC screening in overweight and obese persons.

Methods: We adapted our validated decision analytic model of CRC screening to compare screening starting at 45 or 40 years of age instead of at 50 years of age, or shortening screening intervals, in women and men with body mass index (BMI) ranging from normal to grade III obesity. Strategies included colonoscopy every 10 years (Colo10) or every 5 years (Colo5), or annual fecal immunochemical test.

Results: Without screening, sex-specific total CRC deaths were similar for persons with overweight or obesity I-III, reflecting the counterbalancing of higher CRC risk by lower life expectancy as BMI rises. For all BMI and sex groups, Colo10 starting at 45 years of age or FIT starting at 40 years of age were cost-effective at a threshold of $100,000 per quality-adjusted life year gained. Colo10 starting at 40 years of age was cost-effective only for men with obesity II-III, at $93,300 and $80,400 per quality-adjusted life year gained, respectively. Shifting Colo10 to earlier starting ages was always preferred over Colo5 starting at later ages. Results were robust in sensitivity analysis, including varying all-cause mortality, complication, and BMI-specific CRC risks.

Conclusions: CRC screening starting at 45 years of age with colonoscopy, or at 40 years of age with FIT, appears cost-effective for women and men across the range of BMI. In men with obesity II-III, who have the highest CRC but also all-cause mortality risks, colonoscopy starting at 40 years of age appears cost-effective. It remains to be decided whether BMI should be used as a single predictor or incorporated into a multivariable tool to tailor CRC screening.