Reassessment colonoscopy to diagnose serrated polyposis syndrome in a colorectal cancer screening population

Abstract

Background and study aims Serrated polyposis syndrome (SPS) is a high risk condition for colorectal cancer (CRC). Surveillance strategies for patients with serrated lesions remain controversial. We aimed to evaluate a diagnostic strategy to detect SPS consistently during reassessment colonoscopy in patients with proximal serrated lesions. Methods This was a retrospective study of all individuals from a fecal immunochemical test (FIT)-based CRC screening program (2010-2013) with one or more serrated lesions of ≥ 5 mm proximal to the sigmoid colon on baseline colonoscopy. We analyzed all individuals empirically scheduled for a reassessment colonoscopy aimed at diagnosing SPS within 1 year. Reassessment colonoscopy was performed with standard white-light or chromoendoscopy ± high definition endoscopy depending on availability. SPS diagnosis was based on the cumulative number of polyps in both the baseline and reassessment colonoscopies. Factors associated with SPS diagnosis were analyzed. Results From 3444 screening colonoscopies, 196 patients met the study entry criteria, of whom 11 patients (0.32 %) met the criteria for SPS on baseline colonoscopy. Reassessment colonoscopies were performed in 71 patients at 11.9 ± 1.7 months and detected 20 additional patients with SPS, a tripling of the rate of SPS up to 0.90 %. Independent factors associated with SPS diagnosis were: having five or more proximal serrated lesions (odds ratio [OR] 4.01 [95 % confidence interval 1.20-13.45]; P = 0.02) or two or more sessile serrated polyps ≥ 10 mm (OR 6.35 [1.40-28.81]; P = 0.02) on baseline colonoscopy and the use of chromoendoscopy ± high definition endoscopy during reassessment colonoscopy (OR 4.99 [1.11-22.36]; P = 0.04). Conclusions A 1-year reassessment colonoscopy using chromoendoscopy and high definition endoscopes substantially improves SPS detection in individuals from a FIT-based screening program with proximal serrated lesions. Five or more proximal serrated lesions or two or more sessile serrated polyps ≥ 10 mm could be thresholds for requiring a reassessment colonoscopy. Prospective studies are required to validate these results and adjust surveillance recommendations in patients with serrated lesions.

Narrow-band imaging and high-definition white-light endoscopy in patients with serrated lesions not fulfilling criteria for serrated polyposis syndrome: a randomized controlled trial with tandem colonoscopy

“…One of the most salient findings of our randomized controlled study is that after the scheduled follow-up colonoscopy, nine patients (22%) were reassessed as meeting SPS criteria, both the 2010's and the recently updated 2019's criteria, with important clinical implications in these patients. A similar finding was observed in a retrospective study of a fecal immunochemical test (FIT)-based CRC screening program [12], in which a 1year reassessment colonoscopy of arbitrary selected participants with previous serrated polyps detected by chromoendoscopy and high-definition endoscopes substantially improved SPS detection in those with proximal serrated lesions.…”

“…A randomized controlled trial in patients undergoing their first colonoscopy reported a non-significant trend toward detection of more proximal colon serrated lesions with NBI than with HD-WLE [11]. Finally, in a retrospective selected case series [12] of individuals in a population-based screening program with proximal serrated lesions at the baseline colonoscopy, colonoscopy reassessment within 1 year using chromoendoscopy and high-definition endoscopes led to a three-fold increase in the diagnosis of SPS.…”

Increased Risk of Colorectal Cancer in Patients With Multiple Serrated Polyps and Their First-Degree Relatives

“…In that sense, a recent study showed that in some patients with proximal serrated polyps, a strategy of reassessment colonoscopy using advanced endoscopy techniques can triple the total number of SPS diagnoses made in a fecal immunochemical testbased CRC screening program. 25 Therefore, it is possible that some of the MSP cases could develop SPS by fulfilling the WHO criteria in subsequent colonoscopies. Finally, the risk of CRC in MSP patients could be attributed in part to the higher number of adenomas these patients have.…”

Optimal Endoscopic Treatment and Surveillance of Serrated Polyps

“…48,49 A recent Spanish FIT based cohort followed up all their patients with proximal serrated polyps, tripling the number of additional cases of SPS, for a final prevalence of 1:100. 50 Therefore, especially when using FIT in bowel cancer screening, colonoscopists should be alert to a diagnosis of SPS.…”