Posted on March 19, 2024

March 2024 Colorectal Cancer Awareness—The Year in Review

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. Editor-in-Chief. Email:

Per our annual tradition, this month’s issue of Evidence-Based GI: An ACG Publication is dedicated to clinical research about colorectal cancer (CRC) screening and prevention in honor of CRC Awareness Month.  Through increased CRC screening and the performance of high-quality colonoscopy, we should be gratified by the continued decline in CRC incidence (about 3%-5% per year) among average-risk individuals >50 years old.1 Unfortunately, we’ve also witnessed an alarming rise in the incidence of early-onset CRC (CRC diagnosed in average-risk individuals <50 years old), which is associated with rising rates of obesity and increased consumption of ultra-processed foods and sugar-sweetened beverages.

Our goal is to provide you with concise and thoughtful summaries of the latest and most important clinical research from general medical journals, European gastroenterology journals, and the ACG’s flagship journal, The American Journal of Gastroenterology, so you can optimize the care of your patients.

In this issue, we’ve summarized the seminal randomized controlled trial comparing endoscopic submucosal dissection (ESD) with endoscopic mucosal resection (EMR) for large, non-pedunculated polyps. Although adenoma recurrence rates were significantly higher at 6-month follow-up colonoscopy with EMR (5.1% vs 0.6%), the rate of serious complications was quite a bit higher with ESD. The commentary from our Associate Editor, Jeffrey Lee, MD, MPH, provides context for when to refer patients for ESD (e.g., large rectal polyps with signs of superficial submucosal invasion that benefits from en bloc resection) despite the additional time, increased complications, and the need for advanced training and equipment.

I examine and summarize a groundbreaking Nurses’ Health Study and Health Professionals Follow-Up Study research which demonstrated that increased consumption of ultra-processed foods (e.g., “fast foods” from chain restaurants or “junk foods” from convenience stores) is associated with an increased risk of distal CRC, at least in men. Ultimately, “we are what we eat.”

A summary from our veteran Associate Editor, Philip Okafor, MD, MPH, demonstrates that performing screening colonoscopy in adults > 75 years old with short life expectancies (< 5 years) is quite common in the US. However, the risk of procedural complications rises in older adults with multiple co-morbidities. There can be too much of a good thing, and this summary reminds us to appropriately educate patients when additional screening may not be worthwhile.

Finally, our new Associate Editor, Timothy Yen, MD, summarizes the classic multi-center, European prospective cohort study of serrated polyposis syndrome patients, which demonstrated that colonoscopy surveillance can be extended from annually to bi-annually among patients without advanced neoplasia during clearing colonoscopies.

For our new readers, previous summaries are archived on the EBGI website. In the past 12 months, the CRC Screening and Endoscopy categories include summaries about post-colonoscopy CRC and the importance of taking a second look in the rectum,2 the efficacy of aspirin as chemoprophylaxis for CRC in Lynch syndrome patients,3 simplifying adenoma detection rate calculations,4 the pitfalls of the recent American College of Physicians Guidance on CRC Screening,5 concerns about recommending repeat colonoscopy for colon polyp surveillance despite limited life expectancy6 or  frequently recommending repeat colonoscopy earlier than needed for colon polyp surveillance7  or frequently performing screening colonoscopy in elderly adults with very limited life expectancy,8 and how to interpret the variable findings from research about computer-aided detection of polyps during colonoscopy.9

Yet, there is still so much more that we could have summarized! Although rising obesity rates may increase CRC risk, GLP-1 receptor agonists are very effective for weight reduction and have been associated with decreased CRC risk in patients with Type 2 diabetes.10 It’s gratifying that many community-based practices emphasize high-quality colonoscopy and have demonstrated rising trends in adenoma detection rate and sessile serrated lesion detection rate,11 which should lead to fewer post-colonoscopy CRCs. Artificial intelligence and computer-aided detection of polyps may not be a replacement for the standard tools of high-quality colonoscopy, but rapid software advances continue with improved polyp detection systems12 and new virtual scales 13-14 produce precise endoscopic measurements of polyp size. The future looks bright for endoscopic technology and medical interventions. Nevertheless, our efforts must continue to further reduce the toll of CRC. We should focus on screening the newly eligible 45–49-year-olds and older individuals who have never been screened and overcome obstacles to care.




  1. Shaukat A, Crockett SD. Colorectal Cancer Screening: Time to Spring Forward. Am J Gastroenterol 2024; 119: 395-96.
  2. Lee J. Post-Colonoscopy Colorectal Cancer Due to Missed Polyps in Proximal Colon or Rectum with Sub-Optimal Bowel Cleansing. Evidence-Based GI Jan 16, 2024.
  3. Patel S. In Case You Missed It-Lynch Syndrome: An Aspirin a Day Keeps Colorectal Cancer Away! Evidence-Based GI Dec 12, 2023.
  4. Lee J. Time to Simplify ADR Calculation for Colonoscopy Quality Reporting. Evidence-Based GI Sept 13, 2023.
  5. Schoenfeld P. American College of Physicians Guidance Statement on Colorectal Cancer Screening: Pitfalls of Second-Guessing Guidelines. Evidence-Based GI Sept 13, 2023.
  6. Kumar S. Surveillance Colonoscopy Recommendations in Older Adults with Limited Life Expectancy-More Work to be Done! Evidence-Based GI Aug 16, 2023.
  7. Schoenfeld P. Colonoscopy for Colon Polyp Surveillance: Avoid Recommending Early Surveillance. Evidence-Based GI July 12, 2023.
  8. Okafor P. Screening Colonoscopy in the Elderly Population-Is Less Better? Evidence-Based GI June 13, 2023.
  9. Schoenfeld P. Which Endoscopists Benefit from Using Computer-Aided Detection of Polyps During Colonoscopy? Evidence-Based GI Jan 16, 2024.
  10. Wang L, Wang W, Kaelber DC, et al. GLP-1 Receptor Agonists and Colorectal Cancer Risk in Drug-Naïve Patients with Type 2 Diabetes, with and Without Overweight/Obesity. JAMA Oncol 2024; 10: 256-58.
  11. Liang SY, Oscarson B, Kenkare P, et al. Trends in Detection of Adenoma and Sessile Serrated Lesions Over a Decade in a Community-based Healthcare System. Clin Transl Gastroenterol 2024; In Press. doi: 10.14309/ctg.0000000000000683.
  12. Desai M, Ausk K, Brannan D, et al. Use of a Novel AI System Leads to the Detection of Significantly Higher Number of Adenomas During Screening and Surveillance Colonoscopy. Am J Gastroenterol 2024; In Press. doi: 10.14309/ajg.0000000000002664
  13. Taghiakbari M, Djinbachian R, Haumesser C, et al. Measuring Size of Colorectal Polyps Using a Virtual Scale Endoscope or Visual Assessment. Am J Gastroenterol 2024; In Press. doi: 10.14309/ajg.0000000000002623.
  14. Djinbachian R, Kheilaf A, Noyon B, et al. Accuracy of Measuring Colorectal Polyp Size in Pathology: A Prospective Study. Gut 2023; 72:2015-18.