Clinical consequences of computer-aided colorectal polyp detection.

BACKGROUND AND AIM: Randomised trials show improved polyp detection with computer-aided detection (CADe), mostly of small lesions. However, operator and selection bias may affect CADe's true benefit. Clinical outcomes of increased detection have not yet been fully elucidated. METHODS: In this multicentre trial, CADe combining convolutional and recurrent neural networks was used for polyp detection. Blinded endoscopists were monitored in real time by a second observer with CADe access. CADe detections prompted reinspection. Adenoma detection rates (ADR) and polyp detection rates were measured prestudy and poststudy. Histological assessments were done by independent histopathologists. The primary outcome compared polyp detection between endoscopists and CADe. RESULTS: In 946 patients (51.9% male, mean age 64), a total of 2141 polyps were identified, including 989 adenomas. CADe was not superior to human polyp detection (sensitivity 94.6% vs 96.0%) but outperformed them when restricted to adenomas. Unblinding led to an additional yield of 86 true positive polyp detections (1.1% ADR increase per patient; 73.8% were <5 mm). CADe also increased non-neoplastic polyp detection by an absolute value of 4.9% of the cases (1.8% increase of entire polyp load). Procedure time increased with 6.6±6.5 min (+42.6%). In 22/946 patients, the additional detection of adenomas changed surveillance intervals (2.3%), mostly by increasing the number of small adenomas beyond the cut-off. CONCLUSION: Even if CADe appears to be slightly more sensitive than human endoscopists, the additional gain in ADR was minimal and follow-up intervals rarely changed. Additional inspection of non-neoplastic lesions was increased, adding to the inspection and/or polypectomy workload.

The prospective validation of a scoring system to assess mucosal cleanliness during EGD.

BACKGROUND AND AIMS: Cleanliness of the mucosa of the upper GI (UGI) tract is critical for performing a high-quality EGD. The aim of this study was to validate a recently developed UGI cleanliness scale (the Polprep: Effective Assessment of Cleanliness in Esophagogastroduodenoscopy [PEACE] system) in the detection of clinically significant lesions (CSLs) in the UGI tract. METHODS: Patients who underwent a complete diagnostic EGD were prospectively enrolled from August 2021 to October 2022. The UGI tract (esophagus, stomach, and duodenum) cleanliness was scored from 0 to 3 for each segment. The primary outcomes were the detection of CSLs and PEACE scores. RESULTS: Of 995 patients enrolled from 5 centers, adequate cleanliness (AQ; all scores ≥2) was found in 929 patients. In multivariate regression analysis, AQ was associated with the number of diagnosed CSLs (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.06-3.01; P = .03). Other factors related to CSL detection were duration of EGD (OR, 1.29, 95% CI, 1.23-1.35, P < .001), male sex (OR, 1.33, 95% CI, 1.04-1.71; P = .025), and EGD indication (dyspepsia, alarm symptoms, gastritis surveillance, other indications vs GERD) (OR, 0.43 [95% CI, 0.31-0.6, P < .001], OR, 0.44 [95% CI, 0.28-0.67, P < .001], OR, 0.44 [95% CI, 0.25-0.76; P = .004], and OR, 0.44 [95% CI, 0.31-0.62; P < .001], respectively). Twenty-seven patients were diagnosed with UGI neoplasia, all in patients with adequate cleanliness of the UGI tract. CONCLUSIONS: Adequate cleanliness of the UGI tract as assessed with the PEACE system was associated with a significantly higher detection rate of CSLs during EGD. The relationship of this scale with UGI neoplasia detection warrants further investigation.

Clinical outcome of non-curative endoscopic submucosal dissection for early colorectal cancer.

OBJECTIVE: Endoscopic submucosal dissection (ESD) in a curative intent for submucosa-invasive early (T1) colorectal cancers (T1-CRCs) often leads to subsequent surgical resection in case of histologic parameters indicating higher risk of nodal involvement. In some cases, however, the expected benefit may be offset by the surgical risks, suggesting a more conservative approach. DESIGN: Retrospective analysis of consecutive patients with T1-CRC who underwent ESD at 13 centres ending inclusion in 2019 (n=3373). Cases with high risk of nodal involvement (non-curative ESD: G3, submucosal invasion>1000 µm, lymphovascular involvement, budding or incomplete resection/R1) were analysed if follow-up data (endoscopy/imaging) were available, regardless of the postendoscopic management (follow-up vs surgery) selected by the multidisciplinary teams in these institutions. Comorbidities were classified according to Charlson Comorbidity Index (CCI). Outcomes were disease recurrence, death and disease-related death rates in the two groups. Rate of residual disease (RD) at both the previous resection site and regional lymph nodes was assessed in the surgical cases as well as from follow-up in the follow-up group. RESULTS: Of 604 patients treated by colorectal ESD for submucosally invasive cancer, 207 non-curative resections (34.3%) were included (138 male; mean age 67.6±10.9 years); in 65.2% of cases, no complete resection was achieved (R1). Of the 207 cases, 60.9% (n=126; median CCI: 3; IQR: 2-4) underwent surgical treatment with RD in 19.8% (25/126), while 39.1% (n=81, median CCI: 5; IQR: 4-6) were followed up by endoscopy in all cases. Patients in the follow-up group had a higher overall mortality (HR=3.95) due to non-CRC causes (n=9, mean survival after ESD 23.7±13.7 months). During this follow-up time, tumour recurrence and disease-specific survival rates were not different between the groups (median follow-up 30 months; range: 6-105). CONCLUSION: Following ESD for a lesion at high risk of RD, follow-up only may be a reasonable choice in patients at high risk for surgery. Also, endoscopic resection quality should be improved. TRIAL REGISTRATION NUMBER: NCT03987828.

Linked Colour imaging for the detection of polyps in patients with Lynch syndrome: a multicentre, parallel randomised controlled trial.

OBJECTIVE: Despite regular colonoscopy surveillance, colorectal cancers still occur in patients with Lynch syndrome. Thus, detection of all relevant precancerous lesions remains very important. The present study investigates Linked Colour imaging (LCI), an image-enhancing technique, as compared with high-definition white light endoscopy (HD-WLE) for the detection of polyps in this patient group. DESIGN: This prospective, randomised controlled trial was performed by 22 experienced endoscopists from eight centres in six countries. Consecutive Lynch syndrome patients ≥18 years undergoing surveillance colonoscopy were randomised (1:1) and stratified by centre for inspection with either LCI or HD-WLE. Primary outcome was the polyp detection rate (PDR). RESULTS: Between January 2018 and March 2020, 357 patients were randomised and 332 patients analysed (160 LCI, 172 HD-WLE; 6 excluded due to incomplete colonoscopies and 19 due to insufficient bowel cleanliness). No significant difference was observed in PDR with LCI (44.4%; 95% CI 36.5% to 52.4%) compared with HD-WLE (36.0%; 95% CI 28.9% to 43.7%) (p=0.12). Of the secondary outcome parameters, more adenomas were found on a patient (adenoma detection rate 36.3%; vs 25.6%; p=0.04) and a colonoscopy basis (mean adenomas per colonoscopy 0.65 vs 0.42; p=0.04). The median withdrawal time was not statistically different between LCI and HD-WLE (12 vs 11 min; p=0.16). CONCLUSION: LCI did not improve the PDR compared with HD-WLE in patients with Lynch syndrome undergoing surveillance. The relevance of findings more adenomas by LCI has to be examined further. TRIAL REGISTRATION NUMBER: NCT03344289.

Designs of colonoscopic adenoma detection trials: more positive results with tandem than with parallel studies - an analysis of studies on imaging techniques and mechanical devices.

BACKGROUND AND AIMS: Adenoma detection rate (ADR) has been shown to correlate with interval cancers after screening colonoscopy and is commonly used as surrogate parameter for its outcome quality. ADR improvements by various techniques have been studied in randomised trials using either parallel or tandem methodololgy. METHODS: A systematic literature search was done on randomised trials (full papers, English language) on tandem or parallel studies using either adenoma miss rates (AMR) or ADR as main outcome to test different novel technologies on imaging (new endoscope generation, narrow band imaging, iScan, Fujinon intelligent chromoendoscopy/blue laser imaging and wide angle scopes) and mechanical devices (transparent caps, endocuff, endorings and balloons). Available meta analyses were also screened for randomised studies. RESULTS: Overall, 24 randomised tandem trials with AMR (variable definitions and methodology) and 42 parallel studies using ADR (homogeneous methodology) as primary outcome were included. Significant differences in favour of the new method were found in 66.7% of tandem studies (8222 patients) but in only 23.8% of parallel studies (28 059 patients), with higher rates of positive studies for mechanical devices than for imaging methods. In a random-effects model, small absolute risk differences were found, but these were double in magnitude for tandem as compared with parallel studies (imaging: tandem 0.04 (0.01, 0.07), parallel 0.02 (0.00, 0.04); mechanical devices: tandem 0.08 (0.00, 0.15), parallel 0.04 (0.01, 0.07)). Nevertheless, 94.2% of missed adenomas in the tandem studies were small (<1 cm) and/or non-advanced. CONCLUSIONS: A tandem study is more likely to yield positive results than a simple parallel trial; this may be due to the use of different parameters, variable definitions and methodology, and perhaps also a higher likelihood of bias. Therefore, we suggest to accept positive results of tandem studies only if accompanied by positive results from parallel trials.

Participation in Competing Strategies for Colorectal Cancer Screening: A Randomized Health Services Study (PICCOLINO Study).

BACKGROUND & AIMS: Primary colonoscopy and fecal immunochemical testing (FIT) are considered first-tier tests for colorectal cancer (CRC) screening. Although colonoscopy is considered the most efficacious test, FIT might achieve higher participation rates. It is uncertain what the best strategy is for offering population-wide CRC screening. METHODS: This was a multicenter randomized health services study performed within the framework of the Polish Colonoscopy Screening Program between January 2019 and March 2020 on screening-naïve individuals. Eligible candidates were randomly assigned in a 1:1:1 ratio to participate in 1 of 3 competing invitation strategies: control (invitation to screening colonoscopy only); sequential (invitation to primary colonoscopy and invitation for FIT for initial nonresponders); or choice (invitation offering a choice of colonoscopy or FIT). The primary outcome was participation in CRC screening within 18 weeks after enrollment into the study. The secondary outcome was diagnostic yield for advanced neoplasia. RESULTS: Overall, 12,485 individuals were randomized into the 3 study groups. The participation rate in the control group (17.5%) was significantly lower compared with the sequential (25.8%) and choice strategy (26.5%) groups (P < .001 for both comparisons). The colonoscopy rates for participants with positive FITs were 70.0% for the sequential group and 73.3% for the choice group, despite active call-recall efforts. In the intention-to-screen analysis, advanced neoplasia detection rates were comparable among the control (1.1%), sequential (1.0%), and choice groups (1.1%). CONCLUSIONS: Offering a combination of FIT and colonoscopy as a sequential or active choice strategy increases participation in CRC screening. Increased participation in strategies with FIT do not translate into higher detection of advanced neoplasia. ClinicalTrials.gov, Number NCT03790475.

Recovery of endoscopy services in the era of COVID-19: recommendations from an international Delphi consensus.

The COVID-19 pandemic has had a profound impact on provision of endoscopy services globally as staff and real estate were repurposed. As we begin to recover from the pandemic, a cohesive international approach is needed, and guidance on how to resume endoscopy services safely to avoid unintended harm from diagnostic delays. The aim of these guidelines is to provide consensus recommendations that clinicians can use to facilitate the swift and safe resumption of endoscopy services. An evidence-based literature review was carried out on the various strategies used globally to manage endoscopy during the COVID-19 pandemic and control infection. A modified Delphi process involving international endoscopy experts was used to agree on the consensus statements. A threshold of 80% agreement was used to establish consensus for each statement. 27 of 30 statements achieved consensus after two rounds of voting by 34 experts. The statements were categorised as pre-endoscopy, during endoscopy and postendoscopy addressing relevant areas of practice, such as screening, personal protective equipment, appropriate environments for endoscopy and infection control precautions, particularly in areas of high disease prevalence. Recommendations for testing of patients and for healthcare workers, appropriate locations of donning and doffing areas and social distancing measures before endoscopy are unique and not dealt with by any other guidelines. This international consensus using a modified Delphi method to produce a series of best practice recommendations to aid the safe resumption of endoscopy services globally in the era of COVID-19.

Long-Term Colorectal Cancer Incidence and Mortality After a Single Negative Screening Colonoscopy.

BACKGROUND: Current guidelines recommend a 10-year interval between screening colonoscopies, but evidence is limited. OBJECTIVE: To assess the long-term risk for colorectal cancer (CRC) and death from CRC after a high- and low-quality single negative screening colonoscopy. DESIGN: Observational study. SETTING: Polish Colonoscopy Screening Program. PARTICIPANTS: Average-risk individuals aged 50 to 66 years who had a single negative colonoscopy (no neoplastic findings). MEASUREMENTS: Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) of CRC after high- and low-quality single negative screening colonoscopy. High-quality colonoscopy included a complete examination, with adequate bowel preparation, performed by endoscopists with an adenoma detection rate of 20% or greater. RESULTS: Among 165 887 individuals followed for up to 17.4 years, CRC incidence (0.28 [95% CI, 0.25 to 0.30]) and mortality (0.19 [CI, 0.16 to 0.21]) were 72% and 81% lower, respectively, than in the general population. High-quality examination resulted in 2-fold lower CRC incidence (SIR, 0.16 [CI, 0.13 to 0.20]) and mortality (SMR, 0.10 [CI, 0.06 to 0.14]) than low-quality examination (SIR, 0.32 [CI, 0.29 to 0.35]; SMR, 0.22 [CI, 0.18 to 0.25]). In multivariable analysis, the hazard ratios for CRC incidence after high-quality versus low-quality colonoscopy were 0.55 (CI, 0.35 to 0.86) for 0 to 5 years, 0.54 (CI, 0.38 to 0.77) for 5.1 to 10 years, and 0.46 (CI, 0.25 to 0.86) for 10 to 17.4 years. Only after high-quality colonoscopy did the SIR and SMR for 10.1 to 17.4 years of follow-up not differ compared with earlier observation periods. LIMITATION: The general population was used as the comparison group. CONCLUSION: A single negative screening colonoscopy was associated with reduced CRC incidence and mortality for up to 17.4 years. Only high-quality colonoscopy yielded profound and stable reductions in CRC incidence and mortality throughout the entire follow-up. PRIMARY FUNDING SOURCE: Polish Ministry of Health.

The impact of low- versus standard-volume bowel preparation on participation in primary screening colonoscopy: a randomized health services study.

BACKGROUND: The aim of this study was to evaluate the impact of low-volume vs. standard-volume bowel preparation on participation in screening colonoscopy, bowel preparation quality, and lesion detection rates. METHODS: This was a multicenter, randomized, health services study within the population-based primary colonoscopy screening program in Poland. Individuals aged 55 - 62 years were randomized in a 1:1 ratio to bowel preparation with a low-volume (0.3 L sodium picosulfate with magnesium citrate) or standard-volume (4 L polyethylene glycol) regimen and then invited to participate in screening colonoscopy. The primary outcome measure was the rate of participation in screening colonoscopy. Compliance with the assigned bowel preparation, bowel preparation quality, and lesion detection rates were also evaluated. RESULTS: A total of 13 621 individuals were randomized and 13 497 were analyzed (6752 in the low-volume group and 6745 in the standard-volume group). The participation rate (16.6 % vs. 15.5 %; P = 0.08) and compliance rate (93.3 % vs. 94.1 %; P = 0.39) did not differ significantly between the groups. In the low-volume group, fewer participants had adequate bowel preparation compared with the standard-volume group (whole colon 79.0 % vs. 86.4 %, P < 0.001; proximal colon 80.1 % vs. 87.3 %, P < 0.001). Detection rates of advanced adenoma (AADR) and advanced serrated polyps (ASPDR) were lower in the low-volume group than in the standard-volume group (AADR in the proximal colon 2.6 % vs. 4.3 %, P = 0.02; ASPDR in the whole colon 2.0 % vs. 3.3 %, P = 0.04; ASPDR in the proximal colon 1.0 % vs. 1.9 %, P = 0.048). CONCLUSION: When compared with a standard-volume bowel preparation with polyethylene glycol, low-volume bowel preparation with sodium picosulfate/magnesium citrate did not improve participation rate or lesion detection rates, and negatively affected bowel preparation quality.

Modifiable factors associated with patient-reported pain during and after screening colonoscopy.

OBJECTIVE: Pain associated with colonoscopy is a major burden for patients. We investigated modifiable factors associated with patient-reported pain during and after colonoscopy. DESIGN: This cross-sectional analysis included database records from 23 centres participating in a population-based colonoscopy screening programme in Poland. Colonoscopies were performed under three sedation modalities: none, benzodiazepine-opioid sedation or propofol sedation. We used Gastronet (a validated tool) to assess patients' pain during and after colonoscopy; pain was scored on a four-point scale (no, little, moderate or severe pain), with moderate to severe defined as painful. We used multivariate logistic regression models to estimate ORs for painful colonoscopy and calculated risk-adjusted ratios of painful colonoscopies per endoscopist and compared it to the mean rate. RESULTS: Of 35 216 screening colonoscopies in 2014 and 2015 included in our study, 22 725 (64.5%) patients returned valid Gastronet questionnaires. The proportion of examinations described as causing pain during (after) the procedure was 22.5% (14.2%) for unsedated, 19.9% (13.5%) for benzodiazepine-opioid sedation and 2.5% (7.5%) for propofol sedation. Propofol sedation, higher case volume of endoscopists, newest endoscope generation and adequate bowel preparation were significantly associated with lower odds of painful colonoscopy. Pain scores after colonoscopy showed similar associations. Adjusted pain rates during and after colonoscopy varied 11 and over 23-fold, respectively, between endoscopists. CONCLUSION: We identified several independent, modifiable factors associated with pain during and after colonoscopy, of which individual endoscopist was the most important. Dedicated training should be considered to decrease variability among endoscopists.