Intensive endoscopy surveillance may be unnecessary for patients with small serrated polyps or nonadvanced adenoma, according to study results published in Gastroenterology.
Researchers from Harvard Medical School collected data from 122,899 patients who had previously been enrolled in 3 studies (Nurses’ Health Study 1 [1990-2012], Nurses’ Health Study 2 [1989-2013], and Health Professionals Follow-up Study [1990-2012]). All participants underwent a flexible sigmoidoscopy or colonoscopy. Endoscopy results were categorized as polyp-free, with conventional adenomas, or serrated polyps.
Among the endoscopy results, the majority, 112,107, had no polyps, whereas 6161 participants had conventional adenomas and 5918 had serrated polyps. After a median follow-up period of 10 years, 427 patients who had no polyps, 51 who had conventional adenomas, and 24 who had serrated polyps developed colorectal cancer (CRC).
When compared against patients with no polyps in their original colonoscopy, the hazard ratio (HR) for developing CRC in the advanced adenoma cohort was 4.07 (95% CI, 2.89-5.72; P <.001) and 3.35 (95% CI, 1.37-8.15; P =.008) for participants who had large (≥10 mm) serrated polyps. The study did not report any increased risk of developing CRC in the cohort that had conventional adenomas (HR, 1.21; 95% CI, 0.68-2.16; P =.52), nor in patients who had small (<10 mm) serrated polyps (HR, 1.25; 95% CI, 0.76-2.08; P =.38).
The limitations of this study include the fact that quality of the endoscopies was not reported, and it is unknown whether any of the colonoscopies were incomplete. Furthermore, some of the lesion types had small sample sizes (eg, large serrated polyps [≥10 mm]; n=5), making statistical inference less robust and may not reflect the true HR of the general population.
The investigators concluded, similar to previous studies, that patients with large (≥10 mm) serrated polyps or advanced adenomas are at an increased risk for CRC, and an additional endoscopy within 3 years should be recommended; however, patients with conventional adenomas or small serrated polyps (<10 mm) do not require surveillance more intense than that for patients who were polyp-free.
Disclosures: Some declared author affiliations are with the pharmaceutical industry. A complete list of disclosures can be found in the original study.
He X, Hang D, Wu K, et al. Long-term risk of colorectal cancer after removal of conventional adenomas and serrated polyps. Gastroenterol. 2020;158(4):852-861.