Systematic Reviews
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 7, 2018; 24(1): 124-138
Published online Jan 7, 2018. doi: 10.3748/wjg.v24.i1.124
Systematic review of colorectal cancer screening guidelines for average-risk adults: Summarizing the current global recommendations
Florence Bénard, Alan N Barkun, Myriam Martel, Daniel von Renteln
Florence Bénard, Department of Medicine, University of Montreal (UdeM), and University of Montreal Hospital Research Center (CRCHUM), Montreal, QC H2X 0A9, Canada
Alan N Barkun, Myriam Martel, Division of Gastroenterology, McGill University Health Center, McGill University, Montreal, QC H3G 1A4, Canada
Daniel von Renteln, Department of Medicine, Division of Gastroenterology, University of Montreal Hospital (CHUM), University of Montreal Hospital Research Center (CRCHUM), Montreal, QC H2X 0A9, Canada
Author contributions: Bénard F performed the literature search, drafted and revised the manuscript; Barkun AN was responsible for study concept, search strategy and provided critical revision of manuscript content and concepts; Martel M was responsible for search strategy, performed the literature search, and provided critical revision of manuscript content and concepts; von Renteln D was responsible for concept, design, draft and revision of the manuscript; all authors approved the final version of the manuscript.
Conflict-of-interest statement: Florence Bénard has no potential conflict of interest to disclose. Alan Barkun is the lead clinician for the Quebec colorectal cancer screening program and has received consulting honoraria from Olympus. Myriam Martel has no potential conflict of interest to disclose. Daniel von Renteln is supported through a Fonds de recherche du Québec- Santé (FRQS) career development award, has received consulting honoraria from Boston Scientific and has received research support from ERBE, Vantage and Pentax.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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:
Correspondence to: Daniel von Renteln, MD, Assistant Professor, Department of Medicine, Division of Gastroenterology, Montreal University Hospital (CHUM), Montreal University Hospital Research Center (CRCHUM), 900 Rue Saint-Denis, Montréal, QC H2X 0A9, Canada.
Telephone: +1-514-8908000-30912 Fax: +1-514-4127287
Received: November 2, 2017
Peer-review started: November 3, 2017
First decision: November 21, 2017
Revised: December 12, 2017
Accepted: December 19, 2017
Article in press: December 19, 2017
Published online: January 7, 2018
Research background

Screening has shown to decrease colorectal cancer (CRC) incidence and mortality. Different screening guidelines for average-risk individuals have been issued worldwide, and several guidelines were published or updated recently. To our knowledge, this is the first systematic review aiming to summarize and compare worldwide CRC screening recommendations.

Research motivation

CRC screening recommendations for average-risk individuals differ greatly from one guideline to another, especially when it comes to choosing a preferred screening test. We aimed to compare those recommendations in order to highlight areas of uncertainty, and therefore orient future research by underlining areas where evidence is still lacking.

Research objectives

The main objectives were to compare screening recommendations in order to highlight common ground between guidelines, but also point out discrepancies caused by lack of high-quality evidence, making it easier to orient future research. Knowing which recommendations should clearly be perpetuated and which ones need further investigation can be helpful when it comes to updating guidelines or publishing new ones.

Research methods

A systematic review of the literature was completed to identify all CRC screening guidelines for average-risk individuals published in English in the last ten years and/or position statements published in the last two years. Articles describing an established screening program without issuing recommendations, or articles only reviewing existing guidelines were excluded. Guidelines providing combined recommendations for average-risk and moderate/high-risk individuals, addressing only screening for moderate/high-risk individuals or older versions of existing guidelines were also excluded.

Research results

Fifteen guidelines were included, six of which were published in North America, four in Europe, four in Asia and one by the World Gastroenterology Organization (WGO). A majority of guidelines recommend screening average-risk individuals between ages 50 and 75. Preferred screening methods include colonoscopy (every 10 years), flexible sigmoidoscopy (FS - every 5 years), guaiac-based fecal occult blood test (gFOBT) or fecal immunochemical test (FIT), both repeated annually or biennially. FIT is often recommended over gFOBT, and combining FS with a stool based test is an option that should be considered. The role of colonoscopy varies greatly from one guideline to another, as some identify it as the screening gold standard whilst others highlight the lack of high-quality evidence supporting its use. Screening intervals as well as rank order between tests are also areas of uncertainty.

Research conclusions

Average-risk individuals should undergo CRC screening between ages 50 and 75. Colonoscopy, FS, gFOBT and FIT are recognized as cost-efficient and currently recommended in a majority of guidelines, however their respective role and rank are not clearly established. Local resources availability and patient preferences should be considered when implementing a screening program, in order to maximize screening uptake, as any screening is better than none.

Research perspectives

Establishing a clear ranking of screening methods rather than simply offering a menu of options could be useful in clinical practice. Future research should aim to provide high-quality evidence demonstrating screening tests efficiency, especially colonoscopy, in order to facilitate comparison between tests and help establishing such ranking. Screening intervals should be further investigated.