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Canadian Journal of Gastroenterology and Hepatology
Volume 2016 (2016), Article ID 2878149, 18 pages
Review Article

Colorectal Cancer Screening in Average Risk Populations: Evidence Summary

1Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON, Canada
2Department of Medicine, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
3Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
4Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
5Department of Medicine, University of Toronto, Toronto, ON, Canada
6Program in Evidence-Based Care, Cancer Care Ontario, Hamilton, ON, Canada
7Department of Surgery, St. Michael’s Hospital, Toronto, ON, Canada
8Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, ON, Canada
9Department of Medicine, Division of Gastroenterology, University of Ottawa, The Ottawa Hospital, Ottawa, ON, Canada
10William Osler Health Centre, Etobicoke, ON, Canada
11Vaughan Endoscopy Clinic, Vaughan, ON, Canada
12Northeast Cancer Centre Health Sciences North/Horizon Santé-Nord, Sudbury Outpatient Centre, Sudbury, ON, Canada
13American Society of Clinical Oncology, Alexandria, VA, USA

Received 1 April 2016; Accepted 29 June 2016

Academic Editor: Mark Borgaonkar

Copyright © 2016 Jill Tinmouth et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Introduction. The objectives of this systematic review were to evaluate the evidence for different CRC screening tests and to determine the most appropriate ages of initiation and cessation for CRC screening and the most appropriate screening intervals for selected CRC screening tests in people at average risk for CRC. Methods. Electronic databases were searched for studies that addressed the research objectives. Meta-analyses were conducted with clinically homogenous trials. A working group reviewed the evidence to develop conclusions. Results. Thirty RCTs and 29 observational studies were included. Flexible sigmoidoscopy (FS) prevented CRC and led to the largest reduction in CRC mortality with a smaller but significant reduction in CRC mortality with the use of guaiac fecal occult blood tests (gFOBTs). There was insufficient or low quality evidence to support the use of other screening tests, including colonoscopy, as well as changing the ages of initiation and cessation for CRC screening with gFOBTs in Ontario. Either annual or biennial screening using gFOBT reduces CRC-related mortality. Conclusion. The evidentiary base supports the use of FS or FOBT (either annual or biennial) to screen patients at average risk for CRC. This work will guide the development of the provincial CRC screening program.