Modeling the Economic and Health Impact of Lowering the Recommended Colorectal Cancer Screening Age in Canada Using...

The increasing rates of early-onset colorectal cancer in Canada suggest that earlier screening may be warranted. Canadian guidelines recommend biennial screening at 50 years of age with a fecal immunochemical test (FIT).

OncoSim was used to project the outcomes of revised colorectal cancer screening guidelines in Canada for four cohorts born between 1973 and 1992. Cohort risk ratios were calibrated to Canadian incidence data to reflect early-onset trends. We evaluated the incremental colonoscopy burden of earlier FIT screening and primary colonoscopy screening compared with a reference scenario screening with FIT biennially at 50 years of age (FIT 50). Sensitivity analyses were performed by adjusting screening participation and discount rates.

FIT at 45 and 40 years of age (FIT 45 and FIT 40, respectively) increased the colonoscopy demand by 3.9% and 6.6%, respectively, over the lifetime of screening. Colonoscopy screening resulted in 89.0% to 116.7% more colonoscopies than FIT 50. Screening and total costs increased in all scenarios, but treatment costs decreased. FIT 45 and FIT 40 reduced the incidence by 103 and 161 and colorectal cancer deaths by 43 and 71 per 100,000, respectively. Colonoscopy screening led to 858 to 954 fewer cases and 260 to 303 fewer deaths per 100,000, resp. FIT 45and FIT 40 had incremental cost-effectiveness ratios of $5,850 per quality-adjusted life year (QALY) and $7,038 per QALY, respectively, compared with FIT 50. Colonoscopy scenarios had incremental cost-effectiveness ratios of $2,743 to $7,509 per QALY.

Updated screening can reduce the colorectal cancer burden in younger populations. Increasing FIT screening with earlier initiation is more feasible logistically than increasing colonoscopy first approaches.

These findings may inform future guideline revisions in Canada addressing early-onset colorectal cancer.