Polyp missing rate and its associated risk factors of referring hospitals for endoscopic resection of advanced colorectal neoplasia

Comparison of missed adenomas in deep-sedated and unsedated colonoscopy: A multicenter retrospective study

BACKGROUND

Deep-sedated colonoscopy with propofol is widely used in China. However, its impact on quality metrics remains controversial. We aimed to investigate the effects of deep-sedated colonoscopy on missed adenomas, specifically in each colorectal segment.

METHODS

Data of 3710 individuals from seven hospitals in China who underwent an initial colonoscopy with or without propofol sedation and a second colonoscopy without sedation within six months for surveillance or polypectomy by endoscopist of the same level between October 2020 and September 2021 were retrospectively analyzed.

RESULTS

A total of 1113 missed adenomas in 3710 patients were evaluated. The adenoma miss rate (AMR) was significantly higher in deep-sedated colonoscopy than in unsedated colonoscop [19.14% (578/3020) vs. 16.15% (535/3313), P < 0.05]. The risk of missing adenomas in deep-sedated colonoscopy was 1.229 times higher than in unsedated colonoscopy (OR, 1.229; 95% CI: 1.080-1.399). AMRs of the splenic flexure (26.02% [96/369] vs. 16.04% [47/293], P < 0.05) and descending colon (20.86% [102/489] vs. 13.37% [54/404], P < 0.05) were significantly higher in deep-sedated colonoscopy than in unsedated colonoscopy when performed by middle-level endoscopists rather than high-level endoscopists (P < 0.05).

CONCLUSIONS

AMR was higher in deep-sedated colonoscopy than in unsedated colonoscopy. Furthermore, adenomas in the splenic flexure and descending colon were more frequently missed in deep-sedated colonoscopy than in unsedated colonoscopy, particularly when performed by less experienced endoscopists.

Establishment and evaluation of a nomogram predicting risks of missed diagnoses of colorectal polyps

Background

A missed diagnosis of colorectal polyps during colonoscopy may be associated with the occurrence of interval colorectal cancer. The risk factors for a missed diagnosis or a method to predict the risk of a missed diagnosis of colorectal polyps during colonoscopy remain unidentified.

Methods

The clinical data of patients who underwent two colonoscopies within three months at the Affiliated Hospital of North Sichuan Medical College between February 2017 and August 2019 were retrospectively reviewed. Independent risk factors for missed diagnoses were identified, and a nomogram was established to predict the risk of missed diagnoses. The prediction performance of the nomogram was evaluated using C-index and calibration curves, and its clinical application value was assessed using the Youden index and decision curve analysis.

Results

Independent influencing factors for missed diagnoses included age, endoscopist experience, bowel preparation, retroflected view, withdrawal time, number of polyps in the right colon, and number of polyps ≥ 6 mm. The C-index of the nomogram in the training and validation cohorts was 0.763 (95% confidence interval [CI]: 0.724 − 0.807) and 0.726 (95%CI: 0.657 − 0.794), respectively. The optimal cut-off value of the nomogram calculated using the Youden index was 152.2 points. Under the cut-off value, the sensitivity, specificity, positive predictive value, and negative predictive value were 67.1%, 75.7%, 45.8%, and 88.2%, respectively, in the training cohort, and 57.1%, 79.9%, 53.3%, and 82.3%, respectively, in the validation cohort.

Conclusions

The nomogram provides a reference value for clinicians to analyse the risk of a missed diagnosis of colorectal polyps in individuals, identify high-risk groups, and formulate appropriate follow-up strategies.

Risk of developing metachronous colorectal neoplasia after the resection of proximal versus distal adenomas

BACKGROUND

Current post-polypectomy guidelines do not consider adenoma location. We compared the risk of metachronous colorectal neoplasia (CRN) according to adenoma location.

METHODS

We collected data from 9710 patients who underwent follow-up colonoscopy after adenoma removal. Patients were classified according to baseline adenoma location: distal only (n=4665), proximal only (n=3827), and both sides (n=1218).

RESULTS

The risk of metachronous CRN in patients with proximal only adenomas was higher than that in those with distal only adenomas (adjusted hazard ratio [aHR]=1.12, 95% confidence interval [CI]=1.04-1.21), while the risk of metachronous advanced CRN (ACRN) was not different between the two groups. Among patients aged <50 years, the risk of metachronous CRN in those with proximal only non-advanced adenomas (NAAs) was higher than that in those with only distal NAAs, while among patients aged ≥ 50 years, the risk in those with proximal only advanced adenomas (AAs) was higher than that in those with distal only AAs. However, the risk of metachronous ACRN did not differ based on adenoma location in patients aged < 50 and ≥ 50 years.

CONCLUSIONS

Proximal adenoma was associated with an increased risk of metachronous CRN, but not with an increased risk of metachronous ACRN, supporting the current guidelines recommending the same surveillance interval for distal and proximal adenoma without discrimination by adenoma location.

Detection of Postcolonoscopy Colorectal Neoplasia by Multi-target Stool DNA

INTRODUCTION

Significant variability between colonoscopy operators contributes to postcolonoscopy colorectal cancers (CRCs). We aimed to estimate postcolonoscopy colorectal neoplasia (CRN) detection by multi-target stool DNA (mt-sDNA), which has not previously been studied for this purpose.

METHODS

In a retrospective cohort of patients with +mt-sDNA and completed follow-up colonoscopy, positive predictive value (PPV) for endpoints of any CRN, advanced adenoma, right-sided neoplasia, sessile serrated polyps (SSP), and CRC were stratified by the time since previous colonoscopy (0-9, 10, and ≥11 years). mt-sDNA PPV at ≤9 years from previous average-risk screening colonoscopy was used to estimate CRN missed at previous screening colonoscopy.

RESULTS

Among the 850 studied patients with +mt-sDNA after a previous negative screening colonoscopy, any CRN was found in 535 (PPV 63%). Among 107 average-risk patients having +mt-sDNA ≤9 years after last negative colonoscopy, any CRN was found in 67 (PPV 63%), advanced neoplasia in 16 (PPV 15%), right-sided CRN in 48 (PPV 46%), and SSP in 20 (PPV 19%). These rates were similar to those in 47 additional average risk persons with previous incomplete colonoscopy and in an additional 68 persons at increased CRC risk. One CRC (stage I) was found in an average risk patient who was mt-sDNA positive 6 years after negative screening colonoscopy.

DISCUSSION

The high PPV of mt-sDNA 0-9 years after a negative screening colonoscopy suggests that lesions were likely missed on previous examination or may have arisen de novo. mt-sDNA as an interval test after negative screening colonoscopy warrants further study.

Integrated Imaging Methodology Detects Claudin-1 Expression in Premalignant Nonpolypoid and Polypoid Colonic Epithelium in Mice

OBJECTIVES

Conventional colonoscopy with white light illumination detects colonic adenomas based on structural changes alone and is limited by a high miss rate. We aim to demonstrate an integrated imaging strategy that combines wide-field endoscopy and confocal endomicroscopy in real time to visualize molecular expression patterns in vivo to detect premalignant colonic mucosa.

METHODS

A peptide specific for claudin-1 is labeled with Cy5.5 and administrated intravenously in genetically engineered mice that develop adenomas spontaneously in the distal colon. Wide-field endoscopy is used to identify the presence of nonpolypoid and polypoid adenomas. Anatomic landmarks are used to guide placement of a confocal endomicroscope with side-view optics to visualize claudin-1 expression patterns with subcellular resolution.

RESULTS

Wide-field fluorescence images show peak uptake in colon adenoma at ∼1 hour after systemic peptide administration, and lesion margins are clearly defined. Further examination of the lesion using a confocal endomicroscope shows dysplastic crypts with large size, elongated shape, distorted architecture, and variable dimension compared with normal. The mean fluorescence intensity is significantly higher for dysplasia than normal. Increased claudin-1 expression in dysplasia vs normal is confirmed ex vivo, and the binding pattern is consistent with the in vivo imaging results.

DISCUSSION

Wide-field endoscopy can visualize molecular expression of claudin-1 in vivo to localize premalignant colonic mucosa, and confocal endomicroscopy can identify subcellular feature to distinguish dysplasia from normal.

Berberine versus placebo for the prevention of recurrence of colorectal adenoma: a multicentre, double-blinded, randomised controlled study

BACKGROUND

Chemoprevention of colorectal adenoma and colorectal cancer remains an important public health goal. The present study aimed to investigate the clinical potential and safety of berberine for prevention of colorectal adenoma recurrence.

METHODS

This double-blind, randomised, placebo-controlled trial was done in seven hospital centres across six provinces in China. Individuals aged 18-75 years who had at least one but no more than six histologically confirmed colorectal adenomas that had undergone complete polypectomy within the 6 months before recruitment were recruited and randomly assigned (1:1) to receive berberine (0·3 g twice daily) or placebo tablets via block randomisation (block size of six). Participants were to undergo a first follow-up colonoscopy 1 year after enrolment, and if no colorectal adenomas were detected, a second follow-up colonoscopy at 2 years was planned. The study continued until the last enrolled participant reached the 2-year follow-up point. All participants, investigators, endoscopists, and pathologists were blinded to treatment assignment. The primary efficacy endpoint was the recurrence of adenomas at any follow-up colonoscopy. Analysis was based on modified intention-to-treat, with the full analysis set including all randomised participants who received at least one dose of study medication and who had available efficacy data. The study is registered with ClinicalTrials.gov, number NCT02226185; the trial has ended and this report represents the final analysis.

FINDINGS

Between Nov 14, 2014, and Dec 30, 2016, 553 participants were randomly assigned to the berberine group and 555 to the placebo group. The full analysis set consisted of 429 participants in the berberine group and 462 in the placebo group. 155 (36%) participants in the berberine group and 216 (47%) in the placebo group were found to have recurrent adenoma during follow-up (unadjusted relative risk ratio for recurrence 0·77, 95% CI 0·66-0·91; p=0·001). No colorectal cancers were detected during follow-up. The most common adverse event was constipation (six [1%] of 446 patients in the berberine group vs one [<0·5%] of 478 in the placebo group). No serious adverse events were reported.

INTERPRETATION

Berberine 0·3 g twice daily was safe and effective in reducing the risk of recurrence of colorectal adenoma and could be an option for chemoprevention after polypectomy.

FUNDING

National Natural Science Foundation of China.

Adenoma miss rate determined by very shortly repeated colonoscopy: Retrospective analysis of data from a single tertiary medical center in China

Adenoma miss rate (AMR) has been calculated in several tandem colonoscopy studies, but it costs overmuch to carry out a clinical trial.We aimed to put forward AMR by taking advantage of retrospective data, and to judge the comparability between AMRs from prospective and retrospective data.Data of the patients accepting repeated colonoscopies during January to September 2016 was retrospectively collected and analyzed. Information was recorded, including bowel preparation quality of the first colonoscopy, size, location, histology and whether missed within the first colonoscopy of each single adenoma. AMR was compared by different risk factors through χ test and multivariable logistic regression.Around 267 adenomas were detected during 309 pairs of repeated colonoscopies, of which 66 were missed during the first colonoscopies. AMRs of the lesions small in size, nonadvanced in histology, in poor bowel preparation context and located in the proximal colon, were significantly higher than the opposite ones, and old age and male were related to adenoma missing (P < .05). In multivariable logistic regression analysis, adenoma-related factors (diminutive in size, poor bowel preparation and located in ascending colon, transverse colon or sigmoid colon), and patient-related factors (older than 60 years, male and poor bowel preparation) were found to be independently associated with missing adenomas (P < .05).AMR of retrospective data is comparable to that of tandem studies. Several risk factors influence AMR dramatically, which should be paid attention to.