Colorectal Cancer Screening

Key message

While self-reported colorectal cancer screening/testing rates are low across provinces and territories, rates have been increasing since 2008.

Indicator definition

The percentage of the population aged 50–74 who reported being up to date on colorectal cancer screening/testing, defined as having done a fecal test in the previous two years and/or having undergone a colonoscopy or sigmoidoscopy in the previous five years for any reason.^† Results are presented by province/territory using data from the 2012 Canadian Community Health Survey.

Target

There is no overall target for being up to date on colorectal cancer screening/testing. The National Colorectal Cancer Screening Network’s programmatic participation target (60% of adults of average risk, aged 50–74, being screened using a fecal test) is being applied to fecal testing rates in this report to provide context for an approximation of how much of the population should be undergoing fecal testing. The target was applied to system performance reporting as of 2015.

Measured since

The 2009 Cancer System Performance Report.

This indicator definition was revised in 2016 to report on colorectal cancer screening/testing done for any reason, rather than screening of only asymptomatic individuals.

Why measure this?

Colorectal cancer screening guidelines from the Canadian Task Force on Preventive Health Care recommend that asymptomatic individuals over age 50 get screened for colorectal cancer using a fecal test every two years or flexible sigmoidoscopy every 10 years.^{1, 2} Regular screening using a fecal test among those aged 50 or older, followed by a colonoscopy for those with an abnormal result, can reduce colorectal cancer mortality.³

Monitoring and reporting on colorectal cancer screening/testing performed for any reason (rather than only for asymptomatic reasons) provides a snapshot of the proportion of the population who have had a test that identifies colorectal cancer within the recommended screening interval, enabling assessment of population-level colorectal cancer risk.

What are the key findings?

• Self-reported colorectal cancer screening/testing rates (fecal test and/or sigmoidoscopy/colonoscopy for any reason) ranged from 22.0% in Nunavut to 65.0% in Manitoba in 2012 (Figure 2.3).
• Colorectal cancer screening/testing increased from 31.0% in 2008 to 48.0% in 2014, based on data from seven jurisdictions (Figure 2.4).
• Self-reported fecal testing rates ranged from 14.5% in Quebec to 52.0% in Manitoba in 2012. Fecal testing rates in all provinces/territories were below the 60% participation target (Figure 2.5).
• Colorectal cancer screening/testing rates (fecal test and/or sigmoidoscopy/colonoscopy done for any reason) are higher by 5–10 percentage points when screening/testing is done for any reason (vs. asymptomatic reasons only). For fecal testing, rates are again generally higher when the test is done for any reason, by 0.5–4 percentage points (data not shown; see the 2015 Cancer System Performance Report for information on screening in asymptomatic individuals).

Why do these findings matter?

Self-reported colorectal cancer screening/testing rates were lower than rates for breast and cervical cancer. This is not surprising, given that screening programs for colorectal cancer have been in place for a much shorter time than programs for breast and cervical cancer. While many colorectal cancer screening programs were either not started or in their infancy in 2012, as of the summer of 2015, all 10 provinces had organized programs in place (though programs in Quebec and New Brunswick were not yet province-wide). No screening programs were in place in the territories.⁴ Variations in colorectal cancer screening/testing across the country may partly reflect different stages of screening program announcement and roll-out in different provinces/territories. Variations may also reflect the various primary care initiatives (e.g., physician referral) adopted in some jurisdictions to increase opportunistic colorectal cancer screening, as well as different population characteristics that may drive colorectal cancer screening/testing beyond asymptomatic screening.

Provinces/territories will likely move toward the 60% participation rate target for fecal testing as programs ramp up across the country, as targeted efforts are put in place to increase uptake and as more current data become available. Monitoring colorectal cancer screening/testing participation rates at the system level facilitates evaluation of practices across the country (including program roll-out and implementation, as well as opportunistic screening) and reveals what proportion of the population is protected against this screenable cancer at a given time. Monitoring can help to identify where there are gaps in coverage (e.g., underserved populations).

Notes

^† A fecal occult blood test can be either a guaiac test (gFOBT) or an immunochemical test (FIT). In 2012, the period the data apply to, the recommended screening interval was 5 years for sigmoidoscopy and 10 years for colonoscopy.⁵ Since the Canadian Community Health Survey does not distinguish between the 2 modalities (sigmoidoscopy and colonoscopy), the 5-year timeframe was used for both.

References

1. Canadian Task Force on Preventive Health Care. Colorectal cancer screening. Recommendation statement from the Canadian Task Force on Preventive Health Care. CMAJ. 2001 Jul 24;165(2):206-8.
2. Canadian Task Force on Preventive Health Care. Colorectal Cancer (2016) [Internet]. Calgary (AB): Canadian Task Force on Preventive Health Care; 2016 [updated 2016 Feb 22; cited 2016 Feb 22]. Available from: http://canadiantaskforce.ca/guidelines/published-guidelines/colorectal-cancer/.
3. Hewitson P, Glasziou P, Watson E, Towler B, Irwig L. Cochrane Systematic Review of Colorectal Cancer Screening Using the Fecal Occult Blood Test (hemoccult): An Update. Am J Gastroenterol. 2008;103(6):1541-9.
4. Cancerview.ca. Colorectal Cancer Screening Guidelines Across Canada: Environmental Scan. Toronto (ON): Canadian Partnership Against Cancer; 2015 Jul.
5. Leddin D, Hunt R, Champion M, Cockeram A, Flook N, Gould M, et al. Canadian Association of Gastroenterology and the Canadian Digestive Health Foundation: Guidelines on colon cancer screening. Can J Gastroenterol. 2004 Feb;18(2):93-9