Modeled Effects of Reducing the Recommended Screening Age for Colorectal Cancer in Canada

Get Permission

In a modeling study reported in JAMA Oncology, Kalyta et al found that reducing the starting age for colorectal cancer screening with the biennial fecal immunochemical test (FIT) in Canada would result in reduction in colorectal cancer burden at a “modest cost.”

As stated by the investigators: “Recent U.S. guideline updates have advocated for colorectal cancer screening to begin at age 45 years in average-risk adults, whereas Canadian screening programs continue to begin screening at age 50 years. Similarities in early-onset colorectal cancer rates in Canada and the [United States] warrant discussion of earlier screening in Canada, but there is a lack of Canadian-specific modeling data to inform this.”

Study Details

The study used OncoSim, a publicly available microsimulation tool led by the Canadian Partnership Against Cancer, to model the effects of earlier screening on colorectal cancer incidence, mortality, and health-care costs in Canada. The analysis included four birth cohorts (those born from 1973–1977, 1978–1982, 1983–1987, and 1988–1992) representative of the Canadian population and accounting for the documented effects of increasing colorectal cancer incidence in younger birth cohorts.

Key Findings

According to modeling, over a 40-year period, compared with initiation of screening at age 50, initiation at age 45 would result in a net 12,188 fewer colorectal cancer cases; 5,261 fewer colorectal cancer deaths; and an added 92,112 quality-adjusted life-years (QALYs) to the population. Initiation of screening at age 40 would result in a net 18,135 fewer colorectal cancer cases; 7,988 fewer colorectal cancer deaths; and an additional 150,373 QALYs.

The cost per QALY decreased with younger birth cohorts to a cost of $762 per QALY when persons born between 1988 and 1992 began screening at age 45, or $2,622 per QALY if screening was initiated at age 40.

Although modeling showed that costs associated with screening and resulting therapeutic interventions increased with earlier screening, there was a decrease in the overall health-care system cost of managing colorectal cancer. For example, lowering the initiation age to 45 and 40 cost an additional $298 million and $649 million, respectively, in screening and resultant treatment costs among all cohorts aged ≥ 40 years; however, savings in the overall cost of colorectal cancer management (diagnosis, treatment, cancer recurrence, palliative, and end-of-life care for all cases diagnosed by screening or not) of $719 million and $1.1 billion for screening initiation at age 45 and 40, respectively, were estimated for all cohorts aged ≥ 40 years.

The investigators concluded: “This economic evaluation study using microsimulation modeling found that earlier screening may reduce colorectal cancer disease burden and add life-years to the Canadian population at a modest cost. Guideline changes suggesting earlier colorectal cancer screening in Canada may be justified, but evaluation of the resulting effects on colonoscopy capacity is necessary.”

Jonathan M. Loree, MD, of BC Cancer–Vancouver, is the corresponding author of the JAMA Oncology article.

Disclosure: The study was supported by BC Cancer Foundation, Health Canada, and others. For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.