Serrated polyp detection and risk of interval post-colonoscopy colorectal cancer: a population-based study

Background Adenoma detection rate (ADR) is a well-established quality indicator for colonoscopy and is inversely associated with the incidence of interval post-colonoscopy colorectal cancer. However, interval post-colonoscopy colorectal cancers frequently develop from serrated polyps, which are not included in the ADR. Therefore, the proximal serrated polyp detection rate (PSPDR) has been proposed as a quality indicator, but its association with interval post-colonoscopy colorectal cancer has not been studied. We aimed to evaluate this potential association based on data collected in the Dutch colorectal cancer screening programme. Methods In this population-based study, using colonoscopy data from the Dutch faecal immunochemical test-based colorectal cancer screening programme and cancer data from the Netherlands Cancer Registry, we evaluated the association between endoscopists' individual PSPDR and their patients' risk of interval post-colonoscopy colorectal cancer with a shared frailty Cox proportional-hazard regression analysis. Participants in the screening programme who were eligible for inclusion were aged 55-76 years, had a positive faecal immunochemical test (cutoff 15 mu g Hb/g faeces at start and changed mid-2014 to 47 mu g Hb/g faeces), were asymptomatic, and underwent a colonoscopy between Jan 1, 2014, and Dec 31, 2020. The PSPDR was defined as the proportion of colonoscopies in which at least one serrated polyp proximal to the descending colon was detected, confirmed by histopathology. The ADR was defined as the proportion of all colonoscopies in which at least one conventional adenoma was detected, confirmed by histopathology. Detection rates were determined for each endoscopist individually. We additionally evaluated the risk of interval post-colonoscopy colorectal cancer for endoscopists with a PSPDR and ADR above the median versus endoscopists with either one or both parameters below the median. This study is registered with the Netherlands Trial Registry, NL8350. Findings During the study period, 329 104 colonoscopies were done, of which 277 555, done by 441 endoscopists, were included in the PSPDR calculations. The median PSPDR was 11.9% (IQR 8.3-15.8) and median ADR was 66.3% (61.4-69.9). The correlation between the PSDPR and ADR was moderate (r=0.59; p < 0middot0001). During a median follow-up of 33 months (IQR 21-42), 305 interval post-colonoscopy colorectal cancers were detected. For each percentage point increase in PSPDR, the adjusted interval post-colonoscopy colorectal cancer hazard was 7% lower (hazard ratio [HR] 0.93, 95% CI 0.90-0.95; p < 0middot0001). Compared with endoscopists with a PSPDR greater than 11middot9% and ADR greater than 66middot3%, the HR of interval post-colonoscopy colorectal cancer for endoscopists with a low PSPDR and high ADR was 1.79 (95% CI 1.22-2.63), for endoscopists with a high PSPDR and low ADR was 1.97 (1.19-3.24), and for endoscopists with a low PSPDR and low ADR was 2.55 (1.89-3.45). Gastroenterology, (Prof Gastroenterology the (Prof Interpretation The PSPDR of an endoscopist is inversely associated with the incidence of interval post-colonoscopy colorectal cancer. Implementation of PSPDR monitoring, in addition to ADR monitoring, could optimise colorectal cancer prevention. Copyright (C) 2022 Elsevier Ltd. All rights reserved.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Substantial and sustained improvement of serrated polyp detection after a simple educational intervention: Results from a prospective controlled trial

Objective: Serrated polyps (SPs) are an important cause of postcolonoscopy colorectal cancers (PCCRCs), which is likely the result of suboptimal SP detection during colonoscopy. We assessed the long-term effect of a simple educational intervention focusing on optimising SP detection. Design: An educational intervention, consisting of two 45 min training sessions (held 3 years apart) on serrated polyp detection, was given to endoscopists from 9 Dutch hospitals. Hundred randomly selected and untrained endoscopists from other hospitals were selected as control group. Our primary outcome measure was the proximal SP detection rate (PSPDR) in trained versus untrained endoscopists who participated in our faecal immunochemical test (FIT)-based population screening programme. Results: Seventeen trained and 100 untrained endoscopists were included, who performed 11 305 and 51 039 colonoscopies, respectively. At baseline, PSPDR was equal between the groups (9.3% vs 9.3%). After training, the PSPDR of trained endoscopists gradually increased to 15.6% in 2018. This was significantly higher than the PSPDR of untrained endoscopists, which remained stable around 10% (p=0.018). All below-average (ie, PSPDR ≤6%) endoscopists at baseline improved their PSPDR after training session 1, as did 57% of endoscopists with average PSPDR (6%-12%) at baseline. The second training session further improved the PSPDR in 44% of endoscopists with average PSPDR after the first training. Conclusion: A simple educational intervention was associated with substantial long-term improvement of PSPDR in a prospective controlled trial within FIT-based population screening. Widespread implementation of such interventions might be an easy way to improve SP detection, which may ultimately result in fewer PCCRCs. Trial registration number: NCT03902899

The serrated neoplasia pathway to colorectal cancer: Molecular biology and clinical management

Colorectal cancer (CRC) is one of the most common types of cancer worldwide, and develops from colonic polyps. Traditionally, adenomatous polyps were considered the sole precursor lesion. We now know that 15-30% derives from serrated polyps instead. Serrated polyps are not well understood, and are frequently missed during colonoscopy due to their subtle appearance and (until recently) benign reputation. This seems to results in the development of preventable postcolonoscopy colorectal cancer. In part I of this thesis we therefore focus on improving serrated polyp detection among endoscopist. We demonstrate that education is a very effective intervention to accomplish this. We also describe several driver mutations that might be responsible for malignant conversion of serrated polyps. Part II of this thesis focuses on serrated polyposis syndrome, characterized by many serrated polyps and an increased CRC risk. We studied a new personalised protocol for the surveillance of these patients. This protocol was safe and effective, with a 40% reduction of surveillance colonoscopies without an increased CRC risk. Furthermore, we studied serrated polyposis syndrome patients with a history of extensive colonic surgery. We demonstrate that these patients have a low residual CRC risk, and propose that future studies should assess the safety of extending surveillance intervals for these patients up to five years. Finally, we have analysed over 10 years follow-up data of serrated polyposis syndrome patients in our centre. These data show that endoscopic surveillance is highly effective in CRC prevention, reducing CRC incidence to a near-normal with few colonoscopy related complications

Serrated polyp detection and risk of interval post-colonoscopy colorectal cancer: a population-based study

Background Adenoma detection rate (ADR) is a well-established quality indicator for colonoscopy and is inversely associated with the incidence of interval post-colonoscopy colorectal cancer. However, interval post-colonoscopy colorectal cancers frequently develop from serrated polyps, which are not included in the ADR. Therefore, the proximal serrated polyp detection rate (PSPDR) has been proposed as a quality indicator, but its association with interval post-colonoscopy colorectal cancer has not been studied. We aimed to evaluate this potential association based on data collected in the Dutch colorectal cancer screening programme. Methods In this population-based study, using colonoscopy data from the Dutch faecal immunochemical test-based colorectal cancer screening programme and cancer data from the Netherlands Cancer Registry, we evaluated the association between endoscopists' individual PSPDR and their patients' risk of interval post-colonoscopy colorectal cancer with a shared frailty Cox proportional-hazard regression analysis. Participants in the screening programme who were eligible for inclusion were aged 55-76 years, had a positive faecal immunochemical test (cutoff 15 mu g Hb/g faeces at start and changed mid-2014 to 47 mu g Hb/g faeces), were asymptomatic, and underwent a colonoscopy between Jan 1, 2014, and Dec 31, 2020. The PSPDR was defined as the proportion of colonoscopies in which at least one serrated polyp proximal to the descending colon was detected, confirmed by histopathology. The ADR was defined as the proportion of all colonoscopies in which at least one conventional adenoma was detected, confirmed by histopathology. Detection rates were determined for each endoscopist individually. We additionally evaluated the risk of interval post-colonoscopy colorectal cancer for endoscopists with a PSPDR and ADR above the median versus endoscopists with either one or both parameters below the median. This study is registered with the Netherlands Trial Registry, NL8350. Findings During the study period, 329 104 colonoscopies were done, of which 277 555, done by 441 endoscopists, were included in the PSPDR calculations. The median PSPDR was 11.9% (IQR 8.3-15.8) and median ADR was 66.3% (61.4-69.9). The correlation between the PSDPR and ADR was moderate (r=0.59; p < 0middot0001). During a median follow-up of 33 months (IQR 21-42), 305 interval post-colonoscopy colorectal cancers were detected. For each percentage point increase in PSPDR, the adjusted interval post-colonoscopy colorectal cancer hazard was 7% lower (hazard ratio [HR] 0.93, 95% CI 0.90-0.95; p < 0middot0001). Compared with endoscopists with a PSPDR greater than 11middot9% and ADR greater than 66middot3%, the HR of interval post-colonoscopy colorectal cancer for endoscopists with a low PSPDR and high ADR was 1.79 (95% CI 1.22-2.63), for endoscopists with a high PSPDR and low ADR was 1.97 (1.19-3.24), and for endoscopists with a low PSPDR and low ADR was 2.55 (1.89-3.45). Gastroenterology, (Prof Gastroenterology the (Prof Interpretation The PSPDR of an endoscopist is inversely associated with the incidence of interval post-colonoscopy colorectal cancer. Implementation of PSPDR monitoring, in addition to ADR monitoring, could optimise colorectal cancer prevention. Copyright (C) 2022 Elsevier Ltd. All rights reserved