Canadian Colorectal Cancer Screening Guidelines: Do They Need an Update Given Changing Incidence and Global Practice Patterns?

Abstract

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and second leading cause of cancer death in Canada. Organized screening programs targeting Canadians aged 50 to 74 at average risk of developing the disease have contributed to decreased rates of CRC, improved patient outcomes and reduced healthcare costs. However, data shows that recent incidence reductions are unique to the screening-age population, while rates in people under-50 are on the rise. Similar incidence patterns in the United States prompted the American Cancer Society and U.S. Preventive Services Task Force to recommend screening begin at age 45 rather than 50. We conducted a review of screening practices in Canada, framing them in the context of similar global health systems as well as the evidence supporting the recent U.S. recommendations. Epidemiologic changes in Canada suggest earlier screening initiation in average-risk individuals may be reasonable, but the balance of costs to benefits remains unclear.

Keywords: colon; early-onset; neoplasm; public healthcare; rectal; screening.

Figure 1

Proportion of eligible Canadians up to date with screening (defined as having had a fecal test in the last two years or colonoscopy/sigmoidoscopy in the last ten), based on self-reported data from the 2012 Canadian Community Health Survey [34].

Figure 2

Comparison of annual percent change (APC) by age-group between Canada [56] and the U.S. [13] for colon (a) and rectal (b) cancers. APCs based on most recent published trends.