Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2020; 26(48): 7652-7663
Published online Dec 28, 2020. doi: 10.3748/wjg.v26.i48.7652
Impact of colorectal cancer screening participation in remote northern Canada: A retrospective cohort study
Heather A Smith, Andrew D Scarffe, Nicole Brunet, Cait Champion, Kami Kandola, Alisha Tessier, Robin Boushey, Craig Kuziemsky
Heather A Smith, Department of Surgery, University of Ottawa, Ottawa K1Y4E9, Ontario, Canada
Heather A Smith, Andrew D Scarffe, Telfer School of Management, University of Ottawa, Ottawa K1N6N5, Ontario, Canada
Nicole Brunet, Faculty of Medicine, University of Ottawa, Ottawa K1Y4E9, Ontario, Canada
Cait Champion, Department of Surgery, Northern Ontario School of Medicine, Sudbury P3E2C6, Ontario, Canada
Kami Kandola, Department of Health and Social Services, Government of the Northwest Territories, Yellowknife X1A1P5, Northwest Territories, Canada
Alisha Tessier, Department of Surgery, Stanton Territorial Health Authority, Yellowknife X1A0H1, Northwest Territories, Canada
Robin Boushey, Division of General Surgery, University of Ottawa, Ottawa K1H 8L6, Ontario, Canada
Craig Kuziemsky, Office of Research Services, MacEwan University, Edmonton T5J4S2, Alberta, Canada
Author contributions: Smith HA and Kuziemsky C designed the research study; Smith HA, Kandola K, Tessier A, and Brunet N performed the data collection; Smith HA and Scarffe AD conducted the data analysis; Smith HA, Scarffe AD, and Kuziemsky C wrote the manuscript; and all authors have read and approve the final manuscript.
Supported by University of Ottawa Telfer School of Management Research Grant, No. 603430; Natural Sciences and Engineering Research Council Innovation Grant, No. RGPIN-2019-04884; and the Northern Scientific Training Program.
Institutional review board statement: This study was approved by the Aurora College Research Ethics Committee, protocol No. 20190404.
Informed consent statement: Our data collection was only retrospective and, therefore, no participant consent was required for ethics approval of this study.
Conflict-of-interest statement: All authors confirm no conflict of interests.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at hsmit037@uottawa.ca
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Heather A Smith, MD, Academic Research, Department of Surgery, University of Ottawa, 975 Parkdale Ave, WM150b, Ottawa K1Y4E9, Ontario, Canada. hsmit037@uottawa.ca
Received: September 5, 2020
Peer-review started: September 5, 2020
First decision: September 30, 2020
Revised: October 15, 2020
Accepted: November 21, 2020
Article in press: November 21, 2020
Published online: December 28, 2020
Abstract
BACKGROUND

Screening provides earlier colorectal cancer (CRC) detection and improves outcomes. It remains poorly understood if these benefits are realized with screening guidelines in remote northern populations of Canada where CRC rates are nearly twice the national average and access to colonoscopy is limited.

AIM

To evaluate the participation and impact of CRC screening guidelines in a remote northern population.

METHODS

This retrospective cohort study included residents of the Northwest Territories, a northern region of Canada, age 50-74 who underwent CRC screening by a fecal immunohistochemical test (FIT) between January 1, 2014 to March 30, 2019. To assess impact, individuals with a screen-detected CRC were compared to clinically-detected CRC cases for stage and location of CRC between 2014-2016. To assess participation, we conducted subgroup analyses of FIT positive individuals exploring the relationships between signs and symptoms of CRC at the time of screening, wait-times for colonoscopy, and screening outcomes. Two sample Welch t-test was used for normally distributed continuous variables, Mann-Whitney-Wilcoxon Tests for data without normal distribution, and Chi-square goodness of fit test for categorical variables. A P value of < 0.05 was considered to be statistically significant.

RESULTS

6817 fecal tests were completed, meaning an annual average screening rate of 25.04%, 843 (12.37%) were positive, 629 individuals underwent a follow-up colonoscopy, of which, 24.48% had advanced neoplasia (AN), 5.41% had CRC. There were no significant differences in stage, pathology, or location between screen-detected cancers and clinically-detected cancers. In assessing participation and screening outcomes, we observed 49.51% of individuals referred for colonoscopy after FIT were ineligible for CRC screening, most often due to signs and symptoms of CRC. Individuals were more likely to have AN if they had signs and symptoms of cancer at the time of screening, waited over 180 d for colonoscopy, or were indigenous [respectively, estimated RR 1.18 95%CI of RR (0.89-1.59)]; RR 1.523 (CI: 1.035, 2.240); RR 1.722 (CI: 1.165, 2.547)].

CONCLUSION

Screening did not facilitate early cancer detection but facilitated higher than anticipated AN detection. Signs and symptoms of CRC at screening, and long colonoscopy wait-times appear contributory.

Keywords: Gastroenterology, Rural health services, Public health, Colorectal neoplasms, Early detection of cancer, Northwest Territories

Core Tip: This 5-year retrospective cohort study evaluates the participation and impact of colorectal cancer (CRC) screening guidelines in a northern region of Canada. We evaluated CRC screening results of 6817 participants January, 2014 to March, 2019. We compared the stage and location of screen-detected CRC to clinically-detected CRC cases in 2014-2016. We observed no difference in screen-detected CRC vs clinically detected cases. During the 5-year observation period, we observed a higher incidence of advance neoplasia than anticipated, especially among patients presenting with signs and symptoms of cancer at the time of screening, who experienced long colonoscopy wait-times, and/or who identified as indigenous.