Posted on March 15, 2023

Special Issue Introduction

March Colorectal Cancer Awareness Month

Philip Schoenfeld, MD, MSEd, MSc (Epi)

Chief (Emeritus), Gastroenterology Section, John D. Dingell VA Medical Center, Detroit, MI

Correspondence to Philip Schoenfeld, MD, MSEd, MSc (Epi), Editor-in-Cheif. Email:


This month’s issue of Evidence-Based GI: An ACG Publication (EBGI) is dedicated to clinical research about colorectal cancer (CRC) screening and prevention in honor of Colorectal Cancer Awareness Month.  Generally, CRC Awareness Month activities focus on educating individuals about CRC prevention through screening and reaching out to underserved communities to improve adherence to screening.  However, as gastroenterologists, our primarily role is to prevent CRC through the performance of high-quality colonoscopy, which has been a focus of EBGI since its inception!

In this issue, we summarize that most post-colonoscopy CRCs (PCCRC) occur within 4 years of an index colonoscopy and are due to missed polyps. Conversely, as long as a high-quality and complete colonoscopy is performed by an endoscopist with an acceptable adenoma detection rate (ADR), then repeat screening colonoscopy at 10+ years demonstrate very low rates of advanced adenomas. High-quality colonoscopy also emphasizes complete polyp resection with low adverse events. Another summary from this  issue reviews the first randomized controlled trial to demonstrate that cold snare polypectomy of small polyps decreases severe post-polypectomy bleeding versus hot snare polypectomy.  Finally, endoscopists should strive to  identify under-diagnosed Lynch Syndrome and ensure that all CRCs are tested for deficient mismatch repair proteins with immunohistochemistry.

Ultimately, the first 18 months of EBGI highlight multiple clinical research studies about high-quality colonoscopy for CRC screening. Screening colonoscopy is not beneficial in individuals >75 years old if they have concurrent cardiovascular disease or multiple co-morbidities1, and intervals for surveillance colonoscopy should be extended to 7-10 years if only 1-2 small  adenomas are found.2 Adenoma detection rates up to 40% are associated with lower rates of PCCRC3 and even higher ADRs lower PCCRC in fecal immunochemical test-positive (FIT+) patients.4 Endoscopists should strive to achieve higher ADRs through multiple interventions, including computer-aided detection systems (e.g., GI Genius)5 and extending withdrawal times to 9 minutes6, but this process starts with the audit and feedback of endoscopists.7 These aspirational increases in ADR are appropriate even as we screen 45-49 year olds8, and don’t forget that proximal serrated polyp detection rates are also inversely associated with PCCRCs.9 Optimizing polypectomy technique is  crucial to high-quality colonoscopy since incomplete polyp resection  contributes to PCCRCs.10  A 1-2 mm rim of normal mucosa should be obtained when performing cold snare polypectomy10, but it’s okay to use jumbo forceps for resection of “tiny”, 1-2 mm polyps when their position is not amenable to cold snare polypectomy.11 As discussed above, cold snare polypectomy reduces severe delayed post-polypectomy bleeding in small polyps while also being suitable for piecemeal polypectomy of larger polyps.12 By following these practices, gastroenterologists optimize the value of colonoscopy for CRC screening and provide the evidence-based practices needed to allay concerns about its efficacy.13



  1. Lee J. Screening Colonoscopy Decreases CRC Incidence and CRC-Related Mortality in Patients > 75 Years Old… As Long As They are HEALTHY! Evidence-Based GI October 21, 2021. Accessed March 12, 2023.
  2. Patel S. Wait 7-10 Years for Repeat Colonoscopy If You Only Find 1-2 Small Adenomas. It’s Not Too Long! Evidence-Based GI May 19, 2022. Accessed March 12, 2023.
  3. Lee J. Time to Increase Adenoma Detection Rate Benchmarks for Screening Colonoscopies. Evidence-Based GI September 21, 2022. Accessed date March 12, 2023.
  4. Sleiman J, Schoenfeld P. High Adenoma Detection Rate Decreases Post-Colonoscopy CRC in FIT-Based Screening Program: Quality Matters! Evidence-Based GI October 18, 2022. Accessed March 12, 2023.
  5. Kumar S, Raju G. Computer-aided Detection Systems Increase Detection of non-advanced adenomas, but is it ready for prime-time? Evidence-Based GI December 10, 2021. Access March 12, 2023.
  6. Kolb J, Shaukat A. Slow Down to Speed Up Quality: Longer Withdrawal Time of 9 Versus 6 Minutes Increases Adenoma Detection Rate. Evidence-Based GI January 13, 2022. Accessed March 12, 2023.
  7. Okafor P, Ladabaum U. The Pursuit of Excellence in Colonoscopy: Audit and Feedback Improves Polyp Detection in Low-Performers. Evidence-Based GI April 1, 2022. Accessed March 12, 2023.
  8. Okafor P. Adenoma Detection Rate in 45-49 Year Olds is Lower Compared to 50-54 Year Olds, but Still Higher than 25% Benchmark. Evidence-Based GI July 18, 2022. Accessed March 12, 2023.
  9. Patel S. ADR Isn’t the Only Game in Town: Proximal Serrated Lesion Detection Rates Predicts Interval Cancer Risk. Evidence-Based GI August 11, 2022. Accessed March 12, 2023.
  10. Lee J. Increased Risk of Metachronous Neoplasia After Incomplete Polyp Resection-Time to CARE about Polypectomy Technique. Evidence-Based GI March 2, 2022. Accessed March 12, 2023.
  11. Kumar S. Tiny Polyps-It’s OK to Remove Polyps <3mm with Large or Jumbo Biopsy Forceps! Evidence-Based GI August 11, 2022. Accessed March 12, 2023.
  12. Patel S. Piecemeal Cold Snare Polypectomy of Large Sessile Serrated Polyps is Safe and Effective: Cold is the New Hot! Evidence-Based GI October 22, 2021. Accessed March 12, 2023.
  13. Patel S. Colonoscopy Reduces CRC Incidence and CRC-Related Mortality…If You Get It! Evidence-Based GI October 18, 2022. March 12, 2023.


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