Recommendations for Follow-Up After Colonoscopy and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer

Oral Chinese herbal medicine in reducing the recurrence of colorectal adenoma after polypectomy: A protocol for the systematic review and meta-analysis

BACKGROUND

Colorectal adenoma (CRA) is a significant precancerous lesion of sporadic colorectal cancer (CRC). CRA is likely to recur after polypectomy, increasing the risk of CRC. Chinese herbal medicine (CHM) has been used to reduce CRA recurrence. This review aims to evaluate the effectiveness and safety of oral CHM in reducing CRA recurrence compared to other treatments (placebo, routine care, no treatment, and conventional medicine).

METHODS

We will search for randomised controlled trials (RCTs) from nine major biomedical databases in English and Chinese from their inception to July 2023. The RCTs that investigate the effects of oral CHM in reducing CRA recurrence compared to other treatments will be involved. We will exclude trials using CHM extract or external application of CHM, cohort study and cross-section study. The Cochrane Risk of Bias Tool version 2 will be used to assess the quality of included studies. Data will be analysed using Review Manager software 5.4 and STATA. The random effect model will be used. The heterogeneity of intervention effects will be tested by Chi2 (Cochrane Q) and I2 statistics. Funnel plots will assess publication bias if more than ten studies are included. Subgroup and sensitivity analysis will be conducted when possible.

DISCUSSION

This review will discuss the effectiveness and safety of oral CHM in reducing CRA recurrence. It will show the critical information for clinicians in the decision-making process and countries to develop clinical guidelines on CRA management. Systematic review registration PROSPERO CRD42023324197.

Quality of life after prophylactic surgery for colorectal adenomatous polyposis

PURPOSE

Colorectal adenomatous polyposis is characterized by the onset of tens to thousands of adenomas in the colorectal epithelium and, if not treated, leads to a lifetime increased risk of developing colorectal cancer compared to the general population. Thus, prophylactic surgery is recommended. This study aims to investigate the quality of life of colorectal adenomatous polyposis patients following prophylactic surgery and indirectly compares these findings with those of healthy adults of the normative sample.

METHODS

All patients who underwent prophylactic surgery for polyposis and were in follow-up at the hereditary digestive tract tumors outpatient department of our institute were eligible for the study. The Short Form-36 questionnaire and 21 ad hoc items were used at the time of clinical evaluation.

RESULTS

A total of 102 patients were enrolled. For the SF-36 domains, mean values ranged from 64.18 for vitality to 88.49 for physical functioning, with the highest variability for role-physical limitations; the minimum value of functioning was reached for role-physical limitations, role-emotional limitations, and social functioning. The maximum value of functioning was reached for role-emotional limitations (73.96%) and role-physical limitations (60.42%). In total, 48.96% and 90.63% of patients reported no fecal or urinary incontinence episodes, respectively; 69.79% of patients did not have problems in work/school resumption or the personal sexual sphere.

CONCLUSION

Quality of life following prophylactic surgery for these patients seems to be good when indirectly compared to HP-normative samples'. Young adult patients appear to quickly manage and adapt to changes in bowel functioning. A minority of patients may experience social and sexual issues.

Development and Validation of a Deep Learning-Based Histologic Diagnosis System for Diagnosing Colorectal Sessile Serrated Lesions

OBJECTIVES

The histopathologic diagnosis of colorectal sessile serrated lesions (SSLs) and hyperplastic polyps (HPs) is of low consistency among pathologists. This study aimed to develop and validate a deep learning (DL)-based logical anthropomorphic pathology diagnostic system (LA-SSLD) for the differential diagnosis of colorectal SSL and HP.

METHODS

The diagnosis framework of the LA-SSLD system was constructed according to the current guidelines and consisted of 4 DL models. Deep convolutional neural network (DCNN) 1 was the mucosal layer segmentation model, DCNN 2 was the muscularis mucosa segmentation model, DCNN 3 was the glandular lumen segmentation model, and DCNN 4 was the glandular lumen classification (aberrant or regular) model. A total of 175 HP and 127 SSL sections were collected from Renmin Hospital of Wuhan University during November 2016 to November 2022. The performance of the LA-SSLD system was compared to 11 pathologists with different qualifications through the human-machine contest.

RESULTS

The Dice scores of DCNNs 1, 2, and 3 were 93.66%, 58.38%, and 74.04%, respectively. The accuracy of DCNN 4 was 92.72%. In the human-machine contest, the accuracy, sensitivity, and specificity of the LA-SSLD system were 85.71%, 86.36%, and 85.00%, respectively. In comparison with experts (pathologist D: accuracy 83.33%, sensitivity 90.91%, specificity 75.00%; pathologist E: accuracy 85.71%, sensitivity 90.91%, specificity 80.00%), LA-SSLD achieved expert-level accuracy and outperformed all the senior and junior pathologists.

CONCLUSIONS

This study proposed a logical anthropomorphic diagnostic system for the differential diagnosis of colorectal SSL and HP. The diagnostic performance of the system is comparable to that of experts and has the potential to become a powerful diagnostic tool for SSL in the future. It is worth mentioning that a logical anthropomorphic system can achieve expert-level accuracy with fewer samples, providing potential ideas for the development of other artificial intelligence models.

Surveillance after colorectal polyp resection

Post-polypectomy surveillance has proven to reduce colorectal cancer (CRC) incidence in patients with high-risk polyps, but it implies a major burden on colonoscopy units. Therefore, it should be targeted to individuals with a higher risk. Different societies have published guidelines on surveillance after resection of polyps, with notable discrepancies among them, and many recommendations come from low-quality evidence based on surrogate measures, such as risk of advanced adenoma, and not CRC risk. In this review, we aimed to summarize the evidence supporting post-polypectomy surveillance, compare the recently updated major guidelines, and discuss the existing discrepancies on this topic. Briefly, patients with adenomas ≥10 mm or high-grade dysplasia and patients with serrated polyps ≥10 mm or dysplasia are generally considered to have an increased risk of metachronous CRC and require surveillance, whereas the indication of surveillance is not clearly established in patients without these high-risk features.

Harnessing language models for streamlined postcolonoscopy patient management: a novel approach

BACKGROUND AND AIMS

ChatGPT, an advanced language model, is increasingly used in diverse fields, including medicine. This study explores using ChatGPT to optimize postcolonoscopy management by providing guideline-based recommendations and addressing low compliance rates and timing issues.

METHODS

In this proof-of-concept study, 20 clinical scenarios were prepared as structured reports and free-text notes, and ChatGPT's responses were evaluated by 2 senior gastroenterologists. Compliance with guidelines and accuracy were assessed, and inter-rater agreement was calculated using Fleiss' kappa coefficient.

RESULTS

ChatGPT exhibited 90% compliance with guidelines and 85% accuracy, with a very good inter-rater agreement (Fleiss' kappa coefficient of .84, P < .01). ChatGPT handled multiple variations and descriptions and crafted concise patient letters.

CONCLUSIONS

Results suggest that ChatGPT could aid healthcare providers in making informed decisions and improve compliance with postcolonoscopy surveillance guidelines. Future research should investigate integrating ChatGPT into electronic health record systems and evaluating its effectiveness in different healthcare settings and populations.

New Model to Predict Recurrence After Endoscopic Mucosal Resection of Non-pedunculated Colonic Polyps ≥ 20 mm

BACKGROUND

Polyp recurrence is common after endoscopic mucosal resection (EMR) of non-pedunculated colonic polyps ≥ 20 mm. Two models haven been published for polyp recurrence prediction: Sydney EMR recurrence tool (SERT) and the size, morphology, colonic site, and access to target (SMSA) score. None of these models have been evaluated in a real-world United States (U.S.) cohort. We aimed to evaluate the external validity of these two models and develop a new model.

METHODS

Retrospective cohort study of patients with non-pedunculated polyps ≥ 20 mm that underwent EMR between 1/1/2012 and 6/30/2020. Univariate and multivariate analysis were performed to identify predictors of polyp recurrence to build a new model. Receiver Operating Characteristic (ROC) curves for the new model, SERT and a modified version of SMSA were derived and compared.

RESULTS

A total of 461 polyps from 461 unique patients were included for analysis. The average polyp size was 29.1 ± 12.4 mm. Recurrence rate at first or second surveillance colonoscopy was 29.0% at a 15.6 months median follow up (IQR 12.3-17.4). A model was created with 4 variables from index colonoscopy: size > 40 mm, tubulovillous adenoma histology, right colon location and piecemeal resection. ROC curves showed that the Area Under the ROC (AUC) for the new model was 0.618, for SERT 0.538 and for mSMSA 0.550.

CONCLUSION

SERT score and mSMSA have poor external validity to predict polyp recurrence after EMR of non-pedunculated polyps > 20 mm. Our new model is simpler and performs better in this multiethnic, non-referral cohort from the U.S.

Noninvasive Colorectal Cancer Prevention Options in Older Adults

Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide and its incidence increases with age. The proportion of older adults in the United States continues to rise, making CRC prevention a key health priority for our aging population. CRC is a largely preventable disease through screening and polyp surveillance, and noninvasive modalities represent an important option for older adults in whom the burdens and risks of invasive testing are higher compared with younger adults. This review highlights the evidence, risks, and benefits of noninvasive CRC screening and surveillance options in older adults and discusses the challenges of CRC prevention in this cohort.

9-Minute Withdrawal Time Improves Adenoma Detection Rate Compared With 6-Minute Withdrawal Time During Colonoscopy: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Adenoma detection rate (ADR) is a quality metric that has been emphasized by multiple societies as improved ADR leads to reduced interval colorectal cancer (CRC). It is postulated that increased withdrawal time (WT) can lead to higher ADR. Multiple randomized controlled trials (RCTs) were undertaken to evaluate this. We performed a systematic review and meta-analysis of RCTs to analyze the impact of higher WT on ADR during colonoscopy.

METHODS

The following databases were comprehensively searched through November 8, 2022: Embase, MEDLINE, Cochrane, Web of Science, and Google Scholar. Only RCTs were eligible for inclusion. We applied the random effects model using the DerSimonian Laird approach and calculated risk ratio (RR) for binary outcomes and mean difference (MD) for continuous outcomes. 95% CI and P values were generated.

RESULTS

A total of 3 RCTs with 2159 patients were included of which 1136 patients were included in the 9-minute withdrawal group (9WT) and 1023 patients in the 6-minute withdrawal group (6WT). The mean age range was 53.6 to 56.8 years and the male gender was 50.7%. The overall ADR was significantly higher for 9WT (RR=1.23; 95% CI, 1.09-1.40; P <0.001). The overall adenoma per colonoscopy (APC) was also higher for the 9WT group (MD: 0.14; 95% CI, 0.04-0.25; P =0.008).

CONCLUSION

The 9-minute withdrawal time improved ADR and APC compared with the 6-minute withdrawal. Given the high-quality evidence, we recommend that clinicians at least perform a 9-minute withdrawal to achieve higher quality metrics including ADR to reduce interval CRC.

Usefulness and Educational Benefit of a Virtual Scale Endoscope in Measuring Colorectal Polyp Size

INTRODUCTION

The virtual scale endoscope (VSE) is a newly introduced endoscope that helps endoscopists in measuring colorectal polyp size (CPS) during colonoscopy by displaying a virtual scale. This study aimed to determine the usefulness of the VSE for CPS measurement and the educational benefit of using VSE images to improve CPS estimation accuracy.

METHODS

This study included 42 colorectal polyps in 26 patients treated at Hiroshima University Hospital. In study 1, CPS measured using a VSE before endoscopic mucosal resection was compared with CPS measured on resected specimens, and the agreement between the two measurement methods was evaluated via Bland-Altman analysis. In study 2, 14 endoscopists (5 beginners, 5 intermediates, and 4 experts) took a pre-test to determine the size of 42 polyps. After the pre-test, a lecture on CPS measurement using VSE images was given. One month later, the endoscopists took a post-test to compare CPS accuracy before and after the lecture.

RESULTS

In study 1, Bland-Altman analysis revealed no fixed or proportional errors. The mean bias ±95% limits of agreement (±1.96 standard deviations) of the measurement error was -0.05 ± 0.21 mm, indicating that the agreement between two measurement methods was sufficient. In study 2, the accuracy of CPS measurement was significantly higher among beginners (59.5% vs. 26.7%, p < 0.01) and intermediates (65.2% vs. 44.3%, p < 0.05) in the post-test than in the pre-test.

CONCLUSION

The VSE accurately measures CPS before resection, and its images are useful teaching tools for beginner and intermediate endoscopists.

Colorectal polyp outcomes after participation in the seAFOod polyp prevention trial: Evidence of rebound elevated colorectal polyp risk after short-term aspirin use

BACKGROUND

The seAFOod polyp prevention trial was a randomised, placebo-controlled, 2 × 2 factorial trial of aspirin 300 mg and eicosapentaenoic acid (EPA) 2000 mg daily in individuals who had a screening colonoscopy in the English Bowel Cancer Screening Programme (BCSP). Aspirin treatment was associated with a 20% reduction in colorectal polyp number at BCSP surveillance colonoscopy 12 months later. It is unclear what happens to colorectal polyp risk after short-term aspirin use.

AIM

To investigate colorectal polyp risk according to the original trial treatment allocation, up to 6 years after trial participation.

METHODS

All seAFOod trial participants were scheduled for further BCSP surveillance and provided informed consent for the collection of colonoscopy outcomes. We linked BCSP colonoscopy data to trial outcomes data.

RESULTS

In total, 507 individuals underwent one or more colonoscopies after trial participation. Individuals grouped by treatment allocation were well matched for clinical characteristics, follow-up duration and number of surveillance colonoscopies. The polyp detection rate (PDR; the number of individuals who had ≥1 colorectal polyp detected) after randomization to placebo aspirin was 71.1%. The PDR was 80.1% for individuals who had received aspirin (odds ratio [OR] 1.13 [95% confidence interval 1.02, 1.24]; p = 0.02). There was no difference in colorectal polyp outcomes between individuals who had been allocated to EPA compared with its placebo (OR for PDR 1.00 [0.91, 1.10]; p = 0.92).

CONCLUSION

Individuals who received aspirin in the seAFOod trial demonstrated increased colorectal polyp risk during post-trial surveillance. Rebound elevated neoplastic risk after short-term aspirin use has important implications for aspirin cessation driven by age-related bleeding risk. ISRCTN05926847.

Large serrated polyps indicate a greater risk of advanced metachronous colorectal neoplasia than high-grade adenomas

Background and study aims The risk of developing total metachronous advanced neoplasia (TMAN) in patients with index serrated lesions (SL) or adenoma with high-grade dysplasia (HGD) is unknown. We evaluated this risk in patients with either HGD, SL < 10 mm or SL ≥ 10 mm at index colonoscopy, who underwent surveillance colonoscopies. Patients and methods This retrospective cohort study evaluated all consecutive patients (n = 2477) diagnosed between 2010 and 2019 with colorectal HGD, SLs < 10 mm or SLs ≥ 10 mm. We excluded patients aged < 45 or > 75 years or those who had inflammatory bowel disease, hereditary colorectal cancer (CRC) syndromes, previous or synchronous CRC, or no follow-up colonoscopy. Descriptive variables were compared using analysis of variance or Pearson chi-squared tests. Multivariate Cox regressions were used to compare the risk of TMAN between the HGD, SL < 10 mm and SL ≥ 10 mm groups. Results Overall, 585 patients (mean age 63 years; 55% male; mean follow-up 3.67 years) were included (226 with SLs < 10 mm, 204 with SLs ≥ 10 mm, 155 with HGD). Compared with SLs < 10 mm, patients with HGD did not have a significantly different rate of TMAN (HR=0.75 [0.39-1.44]) and patients with SLs ≥ 10 mm had a higher rate of TMAN (HR=2.08 [1.38-3.15]). Compared with HGD, patients with SLs ≥ 10 mm had a higher rate of TMAN (HR=1.87 [1.04-3.36]). Conclusions The risk for TMAN was higher for patients with SLs ≥ 10 mm than with HGD or SLs < 10 mm. This risk should be considered when planning surveillance intervals for patients diagnosed with large SLs.

Development and validation of a risk prediction model for post-polypectomy colorectal cancer in the USA: a prospective cohort study

Background

Effective risk stratification tools for post-polypectomy colorectal cancer (PPCRC) are lacking. We aimed to develop an effective risk stratification tool for the prediction of PPCRC in three large population-based cohorts and to validate the tool in a clinical cohort.

Methods

Leveraging the integrated endoscopic, histopathologic and epidemiologic data in three U.S population-based cohorts of health professional (the Nurses' Health Study (NHS) I, II and Health Professionals Follow-up Study (HPFS)), we developed a risk score to predict incident PPCRC among 26,741 patients with a polypectomy between 1986 and 2017. We validated the PPCRC score in the Mass General Brigham (MGB) Colonoscopy Cohort (Boston, Massachusetts, U.S) of 76,603 patients with a polypectomy between 2007 and 2018. In all four cohorts, we collected detailed data on patients' demographics, endoscopic history, polyp features, and lifestyle factors at polypectomy. The outcome, incidence of PPCRC, was assessed by biennial follow-up questionnaires in the NHS/HPFS cohorts, and through linkage to the Massachusetts Cancer Registry in the MGB cohort. In all four cohorts, individuals who were diagnosed with CRC or died before baseline or within six months after baseline were excluded. We used Cox regression to calculate the hazard ratio (HR), 95% confidence interval (CI) and assessed the discrimination using C-statistics and reclassification using the Net Reclassification Improvement (NRI).

Findings

During a median follow-up of 12.8 years (interquartile range (IQR): 9.3, 16.7) and 5.1 years (IQR: 2.7, 7.8) in the NHS/HPFS and MGB cohorts, we documented 220 and 241 PPCRC cases, respectively. We identified a PPCRC risk score based on 11 predictors. In the validation cohort, the PPCRC risk score showed a strong association with PPCRC risk (HR for high vs. low, 3.55, 95% CI, 2.59-4.88) and demonstrated a C-statistic (95% CI) of 0.75 (0.70-0.79), and was discriminatory even within the low- and high-risk polyp groups (C-statistic, 0.73 and 0.71, respectively) defined by the current colonoscopy surveillance recommendations, leading to a NRI of 45% (95% CI, 36-54%) for patients with PPCRC.

Interpretation

We developed and validated a risk stratification model for PPCRC that may be useful to guide tailored colonoscopy surveillance. Further work is needed to determine the optimal surveillance interval and test the added value of other predictors of PPCRC beyond those included in the current study, along with implementation studies.

Funding

US National Institutes of Health, the American Cancer Society, the South-Eastern Norway Regional Health Authority, the Deutsche Forschungsgemeinschaft.

Risk of total metachronous advanced neoplasia at surveillance colonoscopy after detection of serrated lesions: a matched case-cohort study

BACKGROUND : Serrated lesions are potential colorectal cancer precursors. This study evaluated the presence of total metachronous advanced neoplasia (T-MAN) at follow-up in patients with index serrated lesions compared with a matched cohort without serrated lesions. METHODS : Patients aged 45-74 years with serrated lesions were matched 2:1 by sex, age, synchronous polyps, and timing of index colonoscopy, to patients without serrated lesions. The primary outcome was T-MAN (advanced adenoma or high-risk serrated lesion) at follow-up. Secondary outcomes included presence of T-MAN stratified by synchronous polyps and serrated lesion characteristics. RESULTS : 1425 patients were included (475 patients, 642 serrated lesions; 950 controls; median follow-up 2.9 versus 3.6 years). Patients with serrated lesions had greater risk of T-MAN than those without (hazard ratio [HR] 6.1, 95 %CI 3.9-9.6). Patients with serrated lesions and high-risk adenoma (HRA) had higher risk of T-MAN than those with HRA alone (HR 2.6, 95 %CI 1.4-4.7); similarly, patients with serrated lesions plus low-risk adenoma (LRA) had higher risk than those with LRA alone (HR 7.0, 95 %CI 2.8-18.4), as did patients with serrated lesions without adenoma compared with no adenoma (HR 14.9, 95 %CI 6.5-34.0). Presence of proximal sessile serrated lesion (SSL; HR 9.3, 95 %CI 5.4-15.9), large SSL (HR 17.8, 95 %CI 7.4-43.3), and proximal large SSL (HR 25.0, 95 %CI 8.8-71.3), but not distal SSL, were associated with greater risk for T-MAN. CONCLUSION : Patients with serrated lesions had higher risk for T-MAN regardless of synchronous adenomas. Patients with serrated lesions and HRA, and those with large or proximal SSLs, were at greatest risk.

A Comparison of Risk Classification Systems of Colorectal Adenomas: A Case-Cohort Study

BACKGROUND & AIMS

Because post-polypectomy surveillance uses a growing proportion of colonoscopy capacity, more targeted surveillance is warranted. We therefore compared surveillance burden and cancer detection using 3 different adenoma classification systems.

METHODS

In a case-cohort study among individuals who had adenomas removed between 1993 and 2007, we included 675 individuals with colorectal cancer (cases) diagnosed a median of 5.6 years after adenoma removal and 906 randomly selected individuals (subcohort). We compared colorectal cancer incidence among high- and low-risk individuals defined according to the traditional (high-risk: diameter ≥10 mm, high-grade dysplasia, villous growth pattern, or 3 or more adenomas), European Society of Gastrointestinal Endoscopy (ESGE) 2020 (high-risk: diameter ≥10 mm, high-grade dysplasia, or 5 or more adenomas), and novel (high-risk: diameter ≥20 mm or high-grade dysplasia) classification systems. For the different classification systems, we calculated the number of individuals recommended frequent surveillance colonoscopy and estimated number of delayed cancer diagnoses.

RESULTS

Four hundred and thirty individuals with adenomas (52.7%) were high risk based on the traditional classification, 369 (45.2%) were high risk based on the ESGE 2020 classification, and 220 (27.0%) were high risk based on the novel classification. Using the traditional, ESGE 2020, and novel classifications, the colorectal cancer incidences per 100,000 person-years were 479, 552, and 690 among high-risk individuals, and 123, 124, and 179 among low-risk individuals, respectively. Compared with the traditional classification, the number of individuals who needed frequent surveillance was reduced by 13.9% and 44.2%, respectively, and 1 (3.4%) and 7 (24.1%) cancer diagnoses were delayed using the ESGE 2020 and novel classifications.

CONCLUSIONS

Using the ESGE 2020 and novel risk classifications will substantially reduce resources needed for colonoscopy surveillance after adenoma removal.

Rates of synchronous advanced neoplasia and colorectal cancer in patients with colonic serrated lesions

BACKGROUND AND AIMS

Serrated lesions (SL) have been associated with significant risks of developing colorectal cancer (CRC). Data on synchronous findings after SL detection during colonoscopy is limited. Study aim was to evaluate the rate of synchronous advanced neoplasia (S-AN) and synchronous CRC (S-CRC) in colonoscopies where SLs were detected.

METHODS

We conducted a retrospective study of screening aged patients 45-74year with colorectal SL (sessile serrated polyp [SSP] or traditional serrated adenoma [TSA]) detected during an elective colonoscopy. Primary outcome was risk of S-AN in patients with SL. Secondary outcomes included risk of S-AN or S-CRC stratified by SL characteristics.

RESULTS

The study included 1262 patients with 1649 SLs (1214 with SSPs and 48 with TSAs). 47.2% were female and 22.9% of exams were screening colonoscopies, 48.2% surveillance, 28.9% diagnostic. The overall rates of S-AN and S-CRC were 15.1% and 1.3%, respectively. Presence of SSPs ≥ 10 mm was associated with higher rates of S-AN, (18.1 vs. 12.2%, Odds-Ratio [OR] = 1.61 [95% Confidence Interval [CI] 1.17-2.23], p = 0.004). SSP dysplasia was predictive of S-AN, (30.3 vs 14.1%, OR = 2.68 [95%CI 1.24-5.78], p = 0.012) but not S-CRC. SSP number (≥ 3) and location (proximal) were not predictors of S-AN or S-CRC.

CONCLUSION

Patients with SLs are at high-risk of S-AN and S-CRC. Findings of SSPs ≥ 10 mm and SSP dysplasia are associated with high-risk of S-AN. Endoscopists should exercise heightened vigilance for synchronous findings when SLs are detected, especially SSPs ≥ 10 mm or when bowel preparation is suboptimal. Studies contrasting synchronous risk of other polyp types are needed to confirm these results.

Polyp characterization using deep learning and a publicly accessible polyp video database

OBJECTIVES

Convolutional neural networks (CNN) for computer-aided diagnosis of polyps are often trained using high-quality still images in a single chromoendoscopy imaging modality with sessile serrated lesions (SSLs) often excluded. This study developed a CNN from videos to classify polyps as adenomatous or nonadenomatous using standard narrow-band imaging (NBI) and NBI-near focus (NBI-NF) and created a publicly accessible polyp video database.

METHODS

We trained a CNN with 16,832 high and moderate quality frames from 229 polyp videos (56 SSLs). It was evaluated with 222 polyp videos (36 SSLs) across two test-sets. Test-set I consists of 14,320 frames (157 polyps, 111 diminutive). Test-set II, which is publicly accessible, 3317 video frames (65 polyps, 41 diminutive), which was benchmarked with three expert and three nonexpert endoscopists.

RESULTS

Sensitivity for adenoma characterization was 91.6% in test-set I and 89.7% in test-set II. Specificity was 91.9% and 88.5%. Sensitivity for diminutive polyps was 89.9% and 87.5%; specificity 90.5% and 88.2%. In NBI-NF, sensitivity was 89.4% and 89.5%, with a specificity of 94.7% and 83.3%. In NBI, sensitivity was 85.3% and 91.7%, with a specificity of 87.5% and 90.0%, respectively. The CNN achieved preservation and incorporation of valuable endoscopic innovations (PIVI)-1 and PIVI-2 thresholds for each test-set. In the benchmarking of test-set II, the CNN was significantly more accurate than nonexperts (13.8% difference [95% confidence interval 3.2-23.6], P = 0.01) with no significant difference with experts.

CONCLUSIONS

A single CNN can differentiate adenomas from SSLs and hyperplastic polyps in both NBI and NBI-NF. A publicly accessible NBI polyp video database was created and benchmarked.

Comparing size measurements of simulated colorectal polyp size and morphology groups when using a virtual scale endoscope or visual size estimation: Blinded randomized controlled trial

OBJECTIVES

The virtual scale endoscope (VSE) allows projection of a virtual scale onto colorectal polyps allowing real-time size measurements. We studied the relative accuracy of VSE compared to visual assessment (VA) for the measuring simulated polyps of different size and morphology groups.

METHODS

We conducted a blinded randomized controlled trial using simulated polyps within a colon model. Sixty simulated polyps were evenly distributed across four size groups (1-5, >5-9.9, 10-19.9, and ≥20 mm) and three Paris morphology groups (flat, sessile, and pedunculated). Six endoscopists performed polyp size measurements using random allocation of either VA or VSE.

RESULTS

A total of 359 measurements were completed. The relative accuracy of VSE was significantly higher when compared to VA for all size groups >5 mm (P = 0.004, P < 0.001, P < 0.001). For polyps ≤5 mm, the relative accuracy of VSE compared to VA was not significantly higher (P = 0.186). The relative accuracy of VSE was significantly higher when compared to VA for all morphology groups. VSE misclassified a lower percentage of >5 mm polyps as ≤5 mm (2.9%), ≥10 mm polyps as <10 mm (5.5%), and ≥20 mm polyps as <20 mm (21.7%) compared to VA (11.2%, 24.7%, and 52.3% respectively; P = 0.008, P < 0.001, and P = 0.003).

CONCLUSION

Virtual scale endoscope had significantly higher relative accuracies for every polyp size group or morphology type aside from diminutive. VSE enables the endoscopist to better classify polyps into correct size categories at clinically relevant size thresholds of 5, 10, and 20 mm.

Linked-Color Imaging Detects More Colorectal Adenoma and Serrated Lesions: An International Randomized Controlled Trial

BACKGROUND & AIMS

Effects of linked-color imaging (LCI) on colorectal lesion detection and colonoscopy quality remain controversial. This study compared the detection rates of adenoma and other precursor lesions using LCI vs white-light imaging (WLI) during screening, diagnostic, and surveillance colonoscopies.

METHODS

This randomized controlled trial was performed at 11 institutions in 4 Asian countries/regions. Patients with abdominal symptoms, a primary screening colonoscopy, positive fecal immunochemical test results, or undergoing postpolypectomy surveillance were recruited and randomly assigned in a 1:1 ratio to either the LCI or high-definition WLI group. The primary outcome was adenoma detection rate (ADR). Secondary outcomes were polyp detection rate, advanced ADR, sessile serrated lesion (SSL) detection rate, and the mean number of adenomas per colonoscopy. The recommended surveillance schedule distribution after trial colonoscopy was analyzed.

RESULTS

Between November 2020 and January 2022, there were 3050 participants (LCI, n = 1527; WLI, n = 1523) recruited. The LCI group ADR was significantly higher than the WLI group ADR using intention-to-treat (58.7% vs 46.7%; P < .01) and per-protocol analyses (59.6% vs 46.4%; P < .01). The LCI group polyp detection rates (68.6% vs 59.5%; P < .01), SSL detection rates (4.8% vs 2.8%; P < .01), and adenomas per colonoscopy (1.48 vs 1.02; P < .01) also were significantly higher. However, the advanced ADR was not significantly different (13.2% vs 11.0%; P = .06). Significantly more patients in the LCI group had shorter recommended surveillance schedules than the WLI group (P < .01).

CONCLUSIONS

Compared with WLI, LCI improved adenoma and other polyp detection rates, including SSLs, resulting in alteration of the recommended surveillance schedule after screening, diagnostic, and postpolypectomy surveillance colonoscopies.

TRIAL REGISTRATION NUMBER

UMIN000042432 (https://www.umin.ac.jp/ctr/index.htm).

The impact of surgical weight loss procedures on the risk of metachronous colorectal neoplasia: the differential effect of surgery type, sex, and anatomic location

Patients with prior colorectal polyps are at high risk for metachronous colorectal neoplasia, especially in the presence of obesity. We assessed the impact of 2 common bariatric surgeries, vertical sleeve gastrectomy and roux-n-Y gastric bypass, on the risk of colorectal neoplasia recurrence. This nationally representative analysis included 1183 postbariatric adults and 3193 propensity score-matched controls, who all had prior colonoscopy with polyps and polypectomy. Colorectal polyps reoccurred in 63.8% of bariatric surgery patients and 71.7% of controls at a mean follow-up of 53.1 months from prior colonoscopy. There was a reduced odds of colorectal polyp recurrence after bariatric surgery compared with controls (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.58 to 0.83). This effect was most pronounced in men (OR = 0.58, 95% CI = 0.42 to 0.79), and post roux-n-Y gastric bypass (OR = 0.57, 95% CI = 0.41 to 0.79). However, the risk of rectal polyps or colorectal cancer remained consistent between groups. This study is the first to our knowledge to show a reduction in risk of polyp recurrence following bariatric surgery.

Use of surveillance colonoscopy among individuals with removal of high-risk polyps according to the US Multi-Society Task Force recommendations

BACKGROUND

Individuals with colorectal polypectomy are recommended to undergo surveillance colonoscopies at certain intervals to prevent subsequent colorectal cancer. Use of postpolypectomy surveillance according to the 2006 US Multi-Society Task Force (USMSTF) recommendations in an integrated health care system was investigated.

METHODS

Use of surveillance colonoscopies was prospectively assessed among 3691 patients with removal of high-risk polyps at a screening colonoscopy during 2007-2012 in the Mass General Brigham Colonoscopy Cohort. With the follow-up up to 2017, the compliance with, overuse, and underuse of postpolypectomy surveillance according to the 2006 USMSTF recommendations was assessed. Surveillance use according to demographic factors was also investigated.

RESULTS

During a median follow-up of 4.4 years (5th percentile, 95th percentile, 1.0, 9.9) 2360 (64%) patients had undergone a surveillance colonoscopy, among whom 758 (21%) were considered compliant with the USMSTF recommendations. A substantial underuse of surveillance colonoscopies of 62% was observed. Older age and lower income were associated with a higher incidence of underuse, whereas having a family history of colorectal cancer were associated with lower incidence of underuse. Overuse of surveillance colonoscopies was present in 17% of patients but showed no significant associations with demographic factors.

CONCLUSION

Substantial underuse of surveillance in patients with high-risk polyps was observed, particularly those with low income and older age. Efforts are needed to improve delivery and use of surveillance colonoscopy.

PLAIN LANGUAGE SUMMARY

The US Multi-Society Task Force recommends follow-up surveillance colonoscopy after polyp removal in the bowel, with intervals depending on the most severe findings. Adherence to surveillance recommendations in a large study with up to 10 years of follow-up among patients with high-risk polyps was investigated. Only 21% of patients adhered to the surveillance recommendations, whereas 62% showed delayed or no use of surveillance. Findings highlight the need for improved use of surveillance colonoscopy among patients at high risk of colorectal cancer.

Association of Life Expectancy With Surveillance Colonoscopy Findings and Follow-up Recommendations in Older Adults

Importance

Surveillance after prior colon polyps is the most frequent indication for colonoscopy in older adults. However, to our knowledge, the current use of surveillance colonoscopy, clinical outcomes, and follow-up recommendations in association with life expectancy, factoring in both age and comorbidities, have not been studied.

Objective

To evaluate the association of estimated life expectancy with surveillance colonoscopy findings and follow-up recommendations among older adults.

Design, Setting, and Participants

This registry-based cohort study used data from the New Hampshire Colonoscopy Registry (NHCR) linked with Medicare claims data and included adults in the NHCR who were older than 65 years, underwent colonoscopy for surveillance after prior polyps between April 1, 2009, and December 31, 2018, and had full Medicare Parts A and B coverage and no Medicare managed care plan enrollment in the year prior to colonoscopy. Data were analyzed from December 2019 to March 2021.

Exposures

Life expectancy (<5 years, 5 to <10 years, or ≥10 years), estimated using a validated prediction model.

Main Outcomes and Measures

The main outcomes were clinical findings of colon polyps or colorectal cancer (CRC) and recommendations for future colonoscopy.

Results

Among 9831 adults included in the study, the mean (SD) age was 73.2 (5.0) years and 5285 (53.8%) were male. A total of 5649 patients (57.5%) had an estimated life expectancy of 10 or more years, 3443 (35.0%) of 5 to less than 10 years, and 739 (7.5%) of less than 5 years. Overall, 791 patients (8.0%) had advanced polyps (768 [7.8%]) or CRC (23 [0.2%]). Among the 5281 patients with available recommendations (53.7%), 4588 (86.9%) were recommended to return for future colonoscopy. Those with longer life expectancy or more advanced clinical findings were more likely to be told to return. For example, among patients with no polyps or only small hyperplastic polyps, 132 of 227 (58.1%) with life expectancy of less than 5 years were told to return for future surveillance colonoscopy vs 940 of 1257 (74.8%) with life expectancy of 5 to less than 10 years and 2163 of 2272 (95.2%) with life expectancy of 10 years or more (P < .001).

Conclusions and Relevance

In this cohort study, the likelihood of finding advanced polyps and CRC on surveillance colonoscopy was low regardless of life expectancy. Despite this observation, 58.1% of older adults with less than 5 years' life expectancy were recommended to return for future surveillance colonoscopy. These data may help refine decision-making about pursuing or stopping surveillance colonoscopy in older adults with a history of polyps.

Risk of Metachronous Neoplasia with High-Risk Adenoma and Synchronous Sessile Serrated Adenoma: A Systematic Review and Meta-Analysis

Background: Sessile serrated adenomas are important precursors to colorectal cancers and account for 30% of colorectal cancers. The United States Multi-Society Task Force recommends that patients with sessile serrated adenomas undergo surveillance similar to tubular adenomas. However, the risk of metachronous neoplasia when the high-risk adenoma co-exists with sessile serrated adenomas is poorly defined. Objective: To examine the risk of metachronous neoplasia in the presence of high-risk adenoma and synchronous sessile serrated adenomas compared with isolated high-risk adenoma. Data sources: PubMed, Embase, Scopus, Cochrane Library. Study selection: A literature search for studies evaluating the risk of metachronous neoplasia in patients with high-risk adenoma alone and those with synchronous high-risk adenoma and sessile serrated adenomas during surveillance colonoscopy was conducted on online databases. Main outcome measures: The primary outcome of interest was the presence of metachronous neoplasia. Results: Of the 1164 records reviewed, six (four retrospective and two prospective) studies met inclusion criteria with 2490 patients (1607 males, mean age 59.98 ± 3.23 years). Average follow-up was 47.5 ± 12.5 months. There were 2068 patients with high-risk adenoma on index colonoscopy and 422 patients with high-risk adenoma and synchronous sessile serrated adenomas. Pooled estimates showed a significantly elevated risk for metachronous neoplasia in patients with high-risk adenoma and synchronous sessile serrated adenomas (pooled odds ratio 2.21; 95% confidence intervals 1.65-2.96; p < 0.01). There was low heterogeneity (I2 = 11%) among the studies. Sensitivity analysis of the prospective studies alone also showed elevated risk of metachronous neoplasm (pooled odds ratio 2.56; 95%, confidence intervals 1.05-6.23; p = 0.04). Limitations: Inclusion of a small number of retrospective studies. Conclusions: The presence of high-risk adenomas and synchronous sessile serrated adenomas is associated with an increased risk of metachronous neoplasia. Therefore, shorter surveillance intervals may be considered in patients with high-risk adenoma and synchronous sessile serrated adenomas compared to those with high-risk adenoma alone.

Current progress on the endoscopic features of colorectal sessile serrated lesions

Along with the discovery and refinement of serrated pathways, the World Health Organization amended the classification of digestive system tumors in 2019, recommending the renaming of sessile serrated adenomas/polyps to sessile serrated lesions (SSLs). Given the particularity of the endoscopic appearance of SSLs, it could easily be overlooked and missed in colonoscopy screening, which is crucial for the occurrence of interval colorectal cancer. Existing literature has found that adequate bowel preparation, reasonable withdrawal time, and awareness of colorectal SSLs have improved the quality and accuracy of detection. More particularly, with the continuous advancement and development of endoscopy technology, equipment, and accessories, a potent auxiliary tool is provided for accurate observation and immediate diagnosis of SSLs. High-definition white light endoscopy, chromoendoscopy, and magnifying endoscopy have distinct roles in the detection of colorectal SSLs and are valuable in identifying the size, shape, character, risk degree, and potential malignant tendency. This article delves into the relevant factors influencing the detection rate of colorectal SSLs, reviews its characteristics under various endoscopic techniques, and expects to attract the attention of colonoscopists.

UTP18-mediated p21 mRNA instability drives adenoma-carcinoma progression in colorectal cancer

Colorectal cancer (CRC) often develops slowly from adenoma, but the underlying mechanism remains unclear, hampering the prevention or treatment of colorectal adenoma-carcinoma progression. In this study, we use in-depth quantitative proteomics combined with survival analysis, revealing that the ribosome protein U3 small nucleolar RNA-associated protein 18 homolog (UTP18) is consistently upregulated in the progression of colorectal adenoma to carcinoma and is associated with adenoma recurrence, effective serodiagnosis, and poor prognosis of CRC. Furthermore, deSUMOylation induces the nucleocytoplasmic transport of UTP18, driving cell-cycle progression and tumorigenesis via mediation of the instability of p21 mRNA. In addition, the growth and ribosome biogenesis of adenoma organoids is found to be promoted by overexpression of UTP18. Thus, UTP18 contributes to multiple roles in adenogenesis and malignancy of CRC, suggesting that it could be a potential biomarker and drug target for colorectal adenoma and cancer.

Impact of Artificial Intelligence on Colonoscopy Surveillance After Polyp Removal: A Pooled Analysis of Randomized Trials

BACKGROUND AND AIMS

Artificial intelligence (AI) tools aimed at improving polyp detection have been shown to increase the adenoma detection rate during colonoscopy. However, it is unknown how increased polyp detection rates by AI affect the burden of patient surveillance after polyp removal.

METHODS

We conducted a pooled analysis of 9 randomized controlled trials (5 in China, 2 in Italy, 1 in Japan, and 1 in the United States) comparing colonoscopy with or without AI detection aids. The primary outcome was the proportion of patients recommended to undergo intensive surveillance (ie, 3-year interval). We analyzed intervals for AI and non-AI colonoscopies for the U.S. and European recommendations separately. We estimated proportions by calculating relative risks using the Mantel-Haenszel method.

RESULTS

A total of 5796 patients (51% male, mean 53 years of age) were included; 2894 underwent AI-assisted colonoscopy and 2902 non-AI colonoscopy. When following U.S. guidelines, the proportion of patients recommended intensive surveillance increased from 8.4% (95% CI, 7.4%-9.5%) in the non-AI group to 11.3% (95% CI, 10.2%-12.6%) in the AI group (absolute difference, 2.9% [95% CI, 1.4%-4.4%]; risk ratio, 1.35 [95% CI, 1.16-1.57]). When following European guidelines, it increased from 6.1% (95% CI, 5.3%-7.0%) to 7.4% (95% CI, 6.5%-8.4%) (absolute difference, 1.3% [95% CI, 0.01%-2.6%]; risk ratio, 1.22 [95% CI, 1.01-1.47]).

CONCLUSIONS

The use of AI during colonoscopy increased the proportion of patients requiring intensive colonoscopy surveillance by approximately 35% in the United States and 20% in Europe (absolute increases of 2.9% and 1.3%, respectively). While this may contribute to improved cancer prevention, it significantly adds patient burden and healthcare costs.

Through the Looking Glass: Surveillance Following Colonoscopic Polypectomy of Malignant Polyps

Introduction Colonoscopic polypectomy is a well-established screening and surveillance modality for malignant colorectal polyps. Following the detection of a malignant polyp, patients are either put on endoscopic surveillance or planned for a surgical procedure. We studied the outcome of colonoscopic excision of malignant polyps and their recurrence rates. Methods We performed a retrospective analysis over a period of five years (2015-2019) of patients who underwent colonoscopy and resection of malignant polyps. Size of polyp, follow-up with tumour markers, CT scan, and biopsy were considered individually for pedunculate and sessile polyps. We analysed the percentage of patients who underwent surgical resection, the percentage of patients who were managed conservatively, and the percentage of recurrence post-excision of malignant polyps. Results A total of 44 patients were included in the study. Of the 44 malignant polyps, most were present in the sigmoid colon at 43% (n=19), with the rectum containing 41% (n=18). The ascending colon accounted for 4.5% (n=2), transverse colonic polyps were 7% (n=3), and the descending colon polyps were 4.5% (n=2). Pedunculated polyps made up 55% (n=24). These were Level 1-3 based on Haggits classification; 14 were Haggits Level 1, eight were Haggits Level 2, and two were Haggits Level 3. The rest were sessile polyps making up 45% (n=20). Based on the Kikuchi classification, these were predominantly SM1 (n=12) and SM2 (n=8). Out of 44 cases, 11% (n=5) underwent surgical resection on follow-up in the form of bowel resection. This included three right hemicolectomies, one sigmoid colectomy, and one low anterior resection. Seven per cent (n=3) underwent endoscopic resection as trans-anal endoscopic mucosal resection (TEMS) and 82% (n=36) of the remaining cases were managed with regular follow-up and surveillance. Conclusions Colonoscopic polypectomy offers excellent benefits in detecting colorectal cancer and treating pre-malignant polyps. Colonoscopic polypectomy provides excellent benefits in colorectal cancer (CRC) detection and treatment of malignant polyps. However, it remains to be seen if post-polypectomy surveillance for low-risk polyp cancers would require a change in surveillance.

The usefulness of fecal hemoglobin and calprotectin tests in diagnosing significant bowel diseases: a prospective study

OBJECTIVES

Although colonoscopy remains the gold standard for determining bowel diseases, it's invasive and expensive. New non-invasive diagnostic methods are urgently needed as an initial screening modality. We aimed to investigate the value of fecal calprotectin (FC) and fecal immunochemical test (FIT) in differentiation of significant and non- significant bowel diseases.

METHODS

In this prospective study, consecutive individuals were included if they underwent colonoscopy for symptoms of lower gastrointestinal (GI) tract, positive fecal occult blood test, surveillance for IBD or colorectal cancer (CRC) screening. Diagnostic value of FC and FIT in discriminating significant bowel diseases (advanced neoplasia, active inflammatory bowel diseases or bowel inflammation due to other causes) and non-significant bowel diseases (normal, asymptomatic diverticulum, non-adenomatous polyp, or non-advanced neoplasia) were evaluated.

RESULTS

Among 201 individuals included, 107 patients had significant bowel diseases. FC and FIT had an area under the curve (AUC) of 0.722 (95% confidence interval [CI] 0.653-0.792) and 0.797 (95%CI 0.734-0.860), respectively, for determining significant bowel diseases. Combination of FC and FIT predicted significant bowel diseases with an AUC, sensitivity, specificity, and accuracy of 0.832 (95% CI 0.775-0.890), 77.6%, 74.5%, and 76.1%, respectively. Moreover, combination of FC and FIT was more sensitive among patients with lower GI symptoms than asymptomatic individuals (80.8% vs. 74.1%) to identify significant bowel diseases.

CONCLUSIONS

A single measurement of FC or FIT is not sufficiently accurate to identify patients with significant bowel disease. However, combination of FC and FIT can help increase the sensitivity, especially in patients with lower GI symptoms.

Epidemiology of overall and early-onset serrated polyps versus conventional adenomas in a colonoscopy screening cohort

Serrated polyps (SPs) are precursors to one-third of colorectal cancers (CRCs), with histological subtypes: hyperplastic polyps (HPs), sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs). The incidence of early-onset CRC before the age of 50 is increasing, with limited understanding of SPs in younger cohorts. Using a large colonoscopy-based cohort, we characterized epidemiologic profiles of SP subtypes, compared to conventional adenomas, with secondary analysis on early-onset polyps. Ninety-four thousand four hundred and twenty-seven patients underwent screening colonoscopies between 2010 and 2018. Demographic, endoscopic and histopathologic characteristics of each polyp subtype were described. High-risk polyps included SSLs ≥10 mm/with dysplasia and conventional adenomas ≥10 mm/with tubulovillous/villous histology/high-grade dysplasia. We examined polyp prevalence with age and compared early- (age < 50) and late-onset polyps (age ≥ 50). Eighteen thousand one hundred and twenty-five patients had SPs (4357 SSLs, 15 415 HPs, 120 TSAs) and 26 699 had conventional adenomas. High-risk SSLs were enriched in the ascending colon (44.1% vs 2.6-35.8% for other locations; P < .003). Early- and late-onset SPs had similar subsite distribution. Early-onset conventional adenomas were more enriched in the distal colon/rectum (51.8% vs 43.4%, P < .001). Multiple conventional adenomas were more represented in late-onset groups (40.8% vs 33.8%, P < .001), with no difference in SSLs. The prevalence of conventional adenomas/high-risk conventional adenomas increased continuously with age, whereas the prevalence of SSLs/high-risk SSLs was stable from age 40 years onwards. A higher proportion of women were diagnosed with early-onset than late-onset SSLs (62.9% vs 57.6%, P = .03). Conventional adenomas, SSLs, early- and late-onset polyps have distinct epidemiology. The findings have implications for improved colonoscopy screening and surveillance and understanding the etiologic heterogeneity of CRC.

Melanosis coli: a contrast effect or an oncogenic effect? A large-scale retrospective cohort study

BACKGROUND

Melanosis coli is characterized by brown mucosa with pigmentation. Studies have showed an increased adenoma detection rate in melanosis patients, whether it is caused by a contrast effect or an oncogenic effect is still controversial. The detection of serrated polys in melanosis patients remains unknown.

AIMS

The study aimed to clarify the correlation of adenoma detection rate with melanosis coli and discuss outcomes in less-experienced endoscopists. Serrated polyp detection rate was also been investigated.

METHODS

A total of 2150 patients and 39,630 controls were enrolled. A propensity score matching method was used to balance covariates between the two groups. The detection of polyps, adenomas, serrated polyps, and their features was analyzed.

RESULTS

The polyp detection rate (44.65% vs 41.01%, P = 0.005) and adenoma detection rate (30.34% vs 23.92%, P < 0.001) were significantly higher, and the serrated polyp detection rate (0.93% vs 1.58%, P = 0.033) was significantly lower in melanosis coli. The percentage of low-risk adenomas (44.60% vs 39.16%, P < 0.001) and polyps with 6 to 10 mm in size (20.16% vs 16.21%, P < 0.001) were higher in melanosis coli. The detection of large serrated polyps was lower (0.11% vs 0.41%, P = 0.026) in melanosis coli.

CONCLUSION

Melanosis coli correlates with an increased adenoma detection rate. The detection of large serrated polyps was lower in melanosis patients. Melanosis coli may not be considered a precancerous lesion.

Risk Factors for Metachronous Colorectal Cancer or Advanced Adenomas After Endoscopic Resection of High-risk Adenomas

BACKGROUND & AIMS

Among the characteristics of high-risk adenomas (HRAs), some may predict a higher risk of metachronous advanced lesions. Our aim was to assess which HRA characteristics are associated with high risk of metachronous colorectal cancer (CRC) or advanced adenomas (AAs).

METHODS

We systematically searched Pubmed, EMBASE, and Cochrane for cohort studies and clinical trials of CRC or AA incidence at surveillance stratified by baseline lesion size, histology, and multiplicity. We calculated pooled relative risks (RRs) using a random-effects model. Heterogeneity was assessed with the I² statistic.

RESULTS

Fifty-five studies were included, with 936,540 patients with mean follow-up 5.4 ± 2.9 years. CRC incidence per 1000 person-years was 2.6 (2.1-3.0) for adenomas ≥20 mm, 2.7 (2.2-3.2) for high-grade dysplasia (HGD), 2.0 (1.8-2.3) for villous component, 0.8 (0.1-1.4) for ≥5 adenomas, 1.0 (0.7-1.2) for ≥3 adenomas. Metachronous CRC risk was higher in adenomas ≥20 mm vs 10 to 19 mm (RR, 2.08; 95% confidence interval [CI], 1.20-3.61), HGD vs low-grade dysplasia (RR, 2.89; 95% CI, 1.88-4.44), villous vs tubular (RR, 1.75; 95% CI, 1.33-2.31). No significant differences in CRC risk were found in ≥3 adenomas vs 1 to 2 (RR, 1.24; 95% CI, 0.84-1.83), nor in ≥5 adenomas vs 3 to 4 (RR, 0.79; 95% CI, 0.30-2.11). Compared with normal colonoscopy, RR for CRC risk was 2.61 (95% CI, 2.06-3.32) for ≥10mm, 6.62 (95% CI, 4.60-9.52) for HGD, 3.58 (95% CI, 2.24-5.73) for villous component, and 2.03 (95% CI, 1.40-2.94) for ≥3 adenomas. Similar trends were seen for metachronous AAs.

CONCLUSION

Metachronous CRC risk is highest in patients with baseline adenomas with ≥20 mm or HGD. Multiplicity does not seem to be associated with substantially higher CRC risk in the near term.

A 5-year evaluation of early-and late-onset sporadic colorectal cancer screening in central Saudi Arabia

Background

The Al-Kharj colorectal cancer (CRC) screening program was implemented for five years (2017-2022) in a central urban area of Riyadh Province, Saudi Arabia, to assess the participation and impact of the program in average-risk individuals.

Methods

The high sensitivity-guaiac based-fecal occult blood test (HSgFOBT) was used as a first-line investigation to identify asymptomatic patients, aged 45-75 years, requiring CRC screening using colonoscopy. The program was run in three tertiary hospitals in the area.

Results

The five-year participation rate was 73% (35,640/48,897). The average age was 53 years (range 45-75), 49% were female (17,464/35,640), all were asymptomatic, and 77% had adequate bowel preparation. The HSgFOBT (+) rate was 6.3% (n = 2245), and 76% (n = 1701) of these underwent colonoscopy. The prevalence of findings were as follows: CRC, 4.8% (81/1701); advanced adenoma, 9.5% (162/1701); adenoma, 15.9% (270/1701); non-adenomatous polyps, 7.9% (135/1701); and no polyps or tumors, 25.4% (432/1701). Among participants aged 45-50 years, early onset-CRC had female predominance, while those ≥50 years with late onset-CRC were predominantly male. CRC was more prevalent in the left colon (P < 0.005).

Conclusions

Approximately one-third of the participants diagnosed with CRC had early-onset CRC. Screening participation was desirable for the defined target population. Public education is necessary along with expanded colonoscopy resources to continue further citizen participation.

Physician Decision-Making About Surveillance in Older Adults With Prior Adenomas: Results From a National Survey

INTRODUCTION

There is no clear guidance on when surveillance colonoscopies should stop in older adults with prior adenomas. We aimed to examine physicians' decision-making regarding surveillance colonoscopies in older adults.

METHODS

In a national mailed survey of 1,800 primary care physicians (PCP) and 600 gastroenterologists, we asked whether physicians would recommend surveillance colonoscopy in vignettes where we varied patient age (75 and 85 years), health (good, medium, and poor), and prior adenoma risk (low and high). We examined the association between surveillance recommendations and patient and physician characteristics using logistic regression. We also assessed decisional uncertainty, need for decision support, and decision-making roles.

RESULTS

Of 1,040 respondents (response rate 54.8%), 874 were eligible and included. Recommendation for surveillance colonoscopies was lower if patient was older (adjusted proportions 20.6% vs 49.8% if younger), in poor health (adjusted proportions 7.1% vs 28.8% moderate health, 67.7% good health), and prior adenoma was of low risk (adjusted proportions 29.7% vs 41.6% if high risk). Family medicine physicians were most likely and gastroenterologists were least likely to recommend surveillance (adjusted proportions 40.0% vs 30.9%). Approximately 52.3% of PCP and 35.4% of gastroenterologists reported uncertainty regarding the benefit/harm balance of surveillance in older adults. Most (85.9% PCP and 77.0% gastroenterologists) would find a decision support tool helpful. Approximately 32.8% of PCP vs 71.5% of gastroenterologists perceived it as the gastroenterologist's role to decide about surveillance colonoscopies.

DISCUSSION

Studies to better evaluate the benefits/harms of surveillance colonoscopy in older adults and decisional support tools that help physicians and patients incorporate such data are needed.

Characteristics of synchronous and metachronous duodenal tumors and association with colorectal cancer: a supplementary analysis

BACKGROUND

We previously reported outcomes of endoscopic resection for duodenal tumors in a large cohort. This study investigated the frequency and characteristics of synchronous and metachronous lesions, and their association with colorectal advanced adenoma (CAA) and colorectal cancer (CRC).

METHODS

Patients underwent duodenal endoscopic resection during January 2008 to December 2018. Background and characteristics, incidence of synchronous and metachronous lesions, and incidence of CAA and CRC were investigated. Patients without synchronous lesions were classified as the single group, and those with synchronous lesions as the synchronous group. Patients were also classified as the metachronous and non-metachronous groups. The characteristics among the groups were compared.

RESULTS

We included 2658 patients with 2881 duodenal tumors: 2472 (93.0%) patients had single, 186 (7.0%) had synchronous, and 54 (2.0%) had metachronous lesions. The 5-year cumulative incidence of metachronous lesions was 4.1%. In total, 208 (7.8%) had CAA and 127 (4.8%) patients had CRC, and colonoscopy was performed in 936 (35.2%) patients. The incidence of CAA in the synchronous groups tended to be higher compared with that in the single groups (11.8% vs 7.5%, adjusted risk ratio 1.56), and the incidence of CRC in the metachronous groups tended to be higher compared with that in the non-metachronous groups (13.0% vs 4.6%, adjusted risk ratio 2.75), but there was no difference after adjusting for colonoscopy.

CONCLUSIONS

This study showed the incidence of synchronous and metachronous duodenal lesions. There was no significant difference in incidence of CAA and CRC among each group, but further studies are warranted.

[Relationship of demographic and dietary hygiene factors with the pathology found in outpatient colonoscopies performed in a Castilla y León Health Service center]

Introduction

Background: colorectal cancer (CRC) is one of the most frequent tumors in terms of incidence and mortality. Several elements, both inherited and environmental, have been related with its pathogenesis. Aims: to analyze the influence of age, gender and nutritional factors on the diagnosis of colonic polyps and CRC. Methods: a prospective, descriptive study over outpatients from the Health Area of León who took a colonoscopy between 09/09/2012 and 06/30/2013. Patients were asked to fill a semiquantitative food frecuency questionnaire with data such a sociodemographic, toxic and dietetic facts. Differences in diagnosis according to sociodemographic and hygiene-dietetic data were analyzed with a multivariate analysis by forward stepwise logistic regression. Results: data were collected from 1390 patients. Mean age was 57.88 (15.17) years and 47.8 % were male. CRC was diagnosed in 5 % of colonoscopies, and polyps in 20.4 %, with 9.4 % of them being HRA. Risk of polyps and HRA was higher in males (26.9 % vs 14.5 %) and (12.6 % vs 6.3 %), respectively (p < 0.001). Mean age was significantly higher in patients who presented polyps (56.51 (15.45) vs 63.22 (12.69) years; p < 0.001). Among the group who reported intake of smoked and salted food, the risk of polyps doubled (2.9 % vs 6.7 %, p = 0.002). In relation to alcohol intake we found that subjects with daily alcohol consumption showed a higher incidence of polyps whe compared to occasional drinkers and teetotallers (32 % vs 20 % vs 18.6 %, p = 0.002) Conclusions: age correlated with higher risk of polyps, HRA and CRC. Moreover, male gender also was associated with a high risk of polyps and HRA. Alcohol and red and processed meat intake increased polyp risk.

Clinical outcomes of colonoscopic polypectomy with strategic surveillance colonoscopies in patients with 10 or more polyps

The clinical usefulness of repeat colonoscopic polypectomy in patients with numerous polyps has not been sufficiently determined. We aimed to analyze the clinical outcomes of colonoscopic polypectomy with surveillance colonoscopies in patients with ≥ 10 polyps. We reviewed the medical records of 152 patients who underwent polypectomy of ≥ 10 polyps at the baseline colonoscopy. We investigated polyp number, polyp size, polypectomy method, procedure time, and adverse events of the baseline colonoscopy. We also investigated the frequency and interval of surveillance colonoscopies and their findings. The mean number of polyps detected at the baseline colonoscopy was 20.0, of which 16.0 polyps were endoscopically resected. The mean size of the largest polyp was 13.4 mm. The mean procedure time was 54.9 min. Post-polypectomy bleeding occurred in 6 (3.9%) patients, all of whom were treated conservatively. No patients developed perforation. With an increasing number of surveillance colonoscopies, the number of detected polyps and the procedure time decreased. Surveillance colonoscopies identified colorectal cancer only in three patients (2.0%), all of which were mucosal cancers that could be curatively treated by polypectomy. Colonoscopic polypectomy with repeat surveillance colonoscopies is a clinically effective, efficient, and safe management option in patients with ≥ 10 polyps.

An Evaluation of Critical Factors for the Cost-Effectiveness of Real-Time Computer-Aided Detection: Sensitivity and Threshold Analyses Using a Microsimulation Model

BACKGROUND

The use of computer-aided detection (CAD) increases the adenoma detection rates (ADRs) during colorectal cancer (CRC) screening/surveillance. This study aimed to evaluate the requirements for CAD to be cost-effective and the impact of CAD on adenoma detection by endoscopists with different ADRs.

METHODS

We developed a semi-Markov microsimulation model to compare the effectiveness of traditional colonoscopy (mean ADR, 26%) to colonoscopy with CAD (mean ADR, 37%). CAD was modeled as having a $75 per-procedure cost. Extensive 1-way sensitivity and threshold analysis were performed to vary cost and ADR of CAD. Multiple scenarios evaluated the potential effect of CAD on endoscopists' ADRs. Outcome measures were reported in incremental cost-effectiveness ratios, with a willingness-to-pay threshold of $100,000/quality-adjusted life year.

RESULTS

When modeling CAD improved ADR for all endoscopists, the CAD cohort had 79 and 34 fewer lifetime CRC cases and deaths, respectively, per 10,000 persons. This scenario was dominant with a cost savings of $143 and incremental effectiveness of 0.01 quality-adjusted life years. Threshold analysis demonstrated that CAD would be cost-effective up to an additional cost of $579 per colonoscopy, or if it increases ADR from 26% to at least 30%. CAD reduced CRC incidence and mortality when limited to improving ADRs for low-ADR endoscopists (ADR <25%), with 67 fewer CRC cases and 28 CRC deaths per 10,000 persons compared with traditional colonoscopy.

CONCLUSIONS

As CAD is implemented clinically, it needs to improve mean ADR from 26% to at least 30% or cost less than $579 per colonoscopy to be cost-effective when compared with traditional colonoscopy. Further studies are needed to understand the impact of CAD on community practice.

Comparing size measurement of colorectal polyps using a novel virtual scale endoscope, endoscopic ruler or forceps: A preclinical randomized trial

Background and study aims  Accurate polyp size measurement is important for guideline conforming choice of polypectomy techniques and subsequent surveillance interval assignments. Some endoscopic tools (biopsy forceps [BF] or endoscopic rulers [ER]) exist to help with visual size estimation. A virtual scale endoscope (VSE) has been developed that allows superimposing a virtual measurement scale during live endoscopies. Our aim was to evaluate the performance of VSE when compared to ER and BF-based measurement. Methods  We conducted a preclinical randomized trial to evaluate the relative accuracy of size measurement of simulated colorectal polyps when using: VSE, ER, and BF. Six endoscopists performed 60 measurements randomized at a 1:1:1 ratio using each method. Primary outcome was relative accuracy in polyp size measurement. Secondary outcomes included misclassification of sizes at the 5-, 10-, and 20-mm thresholds. Results  A total of 360 measurements were performed. The relative accuracy of BF, ER, and VSE was 78.9 % (95 %CI = 76.2-81.5), 78.4 % (95 %CI = 76.0-80.8), and 82.7 % (95 %CI = 80.8-84.8). VSE had significantly higher accuracy compared to BF ( P  = 0.02) and ER ( P  = 0.006). VSE misclassified a lower percentage of polyps > 5 mm as ≤ 5 mm (9.4 %) compared to BF (15.7 %) and ER (20.9 %). VSE misclassified a lower percentage of ≥ 20 mm polyps as < 20 mm (8.3 %) compared with BF (66.7 %) and ER (75.0 %). Of polyps ≥10mm, 25.6 %, 25.5 %, and 22.5 % were misclassified as <10 mm with ER, BF, and VSE, respectively. Conclusions  VSE had significantly higher relative accuracy in measuring polyps compared to ER or BF assisted measurement. VSE improves correct classification of polyps at clinically important size thresholds.

At What Age Should We Stop Colorectal Cancer Screening? When Is Enough, Enough?

There is strong evidence that colorectal cancer screening can reduce both colorectal cancer incidence and mortality. Guidelines recommend screening for individuals age 45 to 75 years, but are less certain about the benefits after age 75 years. Dalmat and colleagues provide evidence that individuals with a prior negative colonoscopy 10 years or more prior to reaching age 76 to 85 years, had a low risk of colorectal cancer, and would be less likely to benefit from further screening. It is important to note that this study population did not include individuals with a family history of colon cancer or a personal history of having high-risk adenomas. These data suggest that a negative colonoscopy can be an effective risk-stratification tool when discussing further screening with elderly patients. See related article by Dalmat et al., p. 37.

Adenoma Detection Rate in Average-Risk Population: An Observational Consecutive Retrospective Study

BACKGROUND

Although colonoscopy is considered the most effective tool for reducing colorectal cancer-related morbidity, the age at which average-risk individuals begin colonoscopic screening is undetermined. This study aimed to compare the adenoma and advanced adenoma detection rates according to age and sex in a large average-risk population in the rural areas of Eastern China.

METHODS

This observational, single-center, retrospective study included patients with average colorectal cancer risk and examined the adenoma and advanced adenoma detection rates using age intervals of 5 years. We also compared the size and age of patients with and without advanced adenoma.

RESULTS

We included 18 928 patients with a median age of 54 years (range 15-90 years), including 10 143 men and 8785 women. The adenoma and advanced adenoma detection rates were 17.08% and 5.24%, respectively, and increased with age in the whole population. The adenoma detection rates increased from 8.97% (aged 40-44) to 14.98% (aged 45-49) and 6.24% (aged 45-49) to 11.00% (aged 50-54) in men and women (both P < .001), respectively. The advanced adenoma detection rates increased from 2.19% (aged 40-44) to 4.76% (aged 45-49) and 1.89% (aged 45-49) to 3.13% (aged 50-54) in men (P = .002) and women (P = .056), respectively. Patients with advanced adenomas were significantly older than those with non-advanced adenomas (P < .001). The tumors in the advanced adenoma group were significantly larger than those in the non-advanced adenoma group (P < .001).

CONCLUSION

The adenoma and advanced adenoma detection rates increased significantly in average-risk population aged 45 years and older, especially in men.

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 revised edition

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: adenoma ≥10 mm in size; 3 to 5 (or more) adenomas; tubulovillous or villous adenoma; adenoma containing high-grade dysplasia; traditional serrated adenoma; sessile serrated lesion containing any grade of dysplasia; serrated polyp of at least 10 mm in size; and 3 to 5 (or more) sessile serrated lesions. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

The Risk of Metachronous Advanced Neoplasia After Colonoscopy in Patients Aged 40-49 Years Compared With That in Patients Aged 50-59 Years

INTRODUCTION

This study investigated the risk of metachronous advanced neoplasia (AN) after colonoscopy in individuals aged 40-49 years compared with that in individuals aged 50-59 years.

METHODS

A retrospective cohort study was performed among Kaiser Permanente Northern California members aged 40-59 years who had their first (index) colonoscopy in 2010-2013. Participants were followed up until death, disenrollment, AN on surveillance colonoscopy, or December 31, 2018. The risk for the development of AN was estimated using the Cox regression, adjusted for confounders.

RESULTS

The study included 11,374 patients (2,396 aged 40-49 years and 8,978 aged 50-59 years). When comparing the 40-49 years group with the 50-59 years group, AN was detected in 2.2% vs 4.4% ( P = 0.0003) on surveillance colonoscopy after index colonoscopy finding of no adenoma, in 4.6% vs 7.0% ( P = 0.03) after a finding of nonadvanced adenoma (NAA), and in 7.9% vs 11.7% ( P = 0.06) after a finding of advanced adenoma (AA), respectively. Compared with the 50-59 years group, the 40-49 years group had a lower risk of metachronous AN when no adenoma was detected on index colonoscopy (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.39-0.83) and no difference when NAA (HR 0.84; 95% CI 0.54-1.24) or AA (HR 0.83; 95% CI 0.51-1.31) was detected.

DISCUSSION

Compared with patients aged 50-59 years, patients aged 40-49 years may have a lower risk of developing metachronous AN when no adenoma is detected on index colonoscopy and a similar risk when NAA or AA is detected. These data suggest current surveillance colonoscopy guidelines may be applicable to patients aged 40-49 years who undergo colonoscopy.

Risk of Metachronous Advanced Colorectal Neoplasia After Removal of Diminutive Versus Small Nonadvanced Adenomas: A Multicenter Study

BACKGROUND

Current postpolypectomy guidelines treat 1-9 mm nonadvanced adenomas (NAAs) as carrying the same level of risk for metachronous advanced colorectal neoplasia (ACRN).

AIMS

To evaluate whether small (6-9 mm) NAAs are associated with a greater risk of metachronous ACRN than diminutive (1-5 mm) NAAs.

METHODS

We retrospectively evaluated 10,060 index colonoscopies performed from July 2011 to June 2019. A total of 1369 patients aged ≥ 40 years with index NAAs and having follow-up examinations were categorized into 5 groups based on size and number of index findings: Group 1, ≤ 2 diminutive NAAs (n = 655); Group 2, ≤ 2 small NAAs (n = 529); Group 3, 3-4 diminutive NAAs (n = 78); Group 4, 3-4 small NAAs (n = 65); and Group 5, 5-10 NAAs (n = 42). Size was classified based on the largest NAA. ACRN was defined as finding an advanced adenoma or colorectal cancer at follow-up.

RESULTS

The absolute risk of metachronous ACRN increased from 7.2% in patients with all diminutive NAAs to 12.2% in patients with at least 1 small NAA (P = 0.002). Patients in Group 2 (adjusted odds ratio [AOR] 1.89; 95% confidence interval [CI], 1.21-2.95), Group 3 (AOR 2.40; 95% CI 1.78-4.90), Group 4 (AOR 2.77; 95% CI 1.35-5.66), and Group 5 (AOR 3.71; 95% CI 1.65-8.37) were associated with an increased risk of metachronous ACRN compared with Group 1.

CONCLUSIONS

Patients with small NAAs have an increased risk of metachronous ACRN. Postpolypectomy guidelines should consider including risk stratification between small and diminutive adenomas.

Creating a Safety Net Process to Improve Colon Cancer Diagnosis in Patients With Rectal Bleeding

Background Failure to follow up on patients with rectal bleeding is common and may result in a delay in diagnosis of colorectal cancer or in missing high-risk adenomas. The authors' purpose was to create an electronic patient safety net for those diagnosed with rectal bleeding but who did not have colonoscopy to ensure proper detection of colonic abnormalities, including colon cancer. Methods In an integrated health delivery system serving < 4.6 million patients in Southern California, from 2014 to 2019, the authors electronically identified patients with rectal bleeding aged 45 to 80 years but with no recently documented colonoscopy. These cases were reviewed by a gastroenterologist to determine if colonoscopy was appropriate. The physician looked for known documentation as to the cause of rectal bleeding and verified no contraindications to the procedure; if indicated, testing was offered. Results Using the authors' safety net program, 1430 patients with rectal bleeding who needed and completed a colonoscopy were identified. Of those patients, 7.5% had an advanced adenoma or cancer, with a total of 20 cancers, and 34% had findings that warranted more frequent colonoscopy. Conclusions The authors designed a safety net system that was able to capture information on patients with rectal bleeding who had not had a colonoscopy and detected in 34% colonic pathology that would have otherwise gone undetected. The program did not require many resources to implement and had the ability to potentially prevent harm from reaching patients whose rectal bleeding did not get prompt workup. Other health systems and practices should consider implementing a similar system.

What size cutoff level should be used to implement optical polyp diagnosis?

BACKGROUND : The risk of advanced pathology increases with polyp size, as does the potential for mismanagement when optical diagnosis is used. This study aimed to evaluate the proportion of patients who would be assigned inadequate surveillance intervals when different size cutoffs are adopted for use of optical diagnosis. METHODS : In a post hoc analysis of three prospective studies, the use of optical diagnosis was evaluated for three polyp size groups: 1-3, 1-5, and 1-10 mm. The primary outcome was the proportion of patients in whom advanced adenomas were found and optical diagnosis resulted in delayed surveillance. Secondary outcomes included agreements between surveillance intervals based on high confidence optical diagnosis and pathology outcomes, reduction in histopathological examinations, and proportion of patients who could receive an immediate surveillance recommendation. RESULTS : We included 3374 patients (7291 polyps ≤ 10 mm) undergoing complete colonoscopies (median age 66.0 years, 75.2 % male, 29.6 % for screening). The percentage of patients with advanced adenomas and either 2- or 7-year delayed surveillance intervals (n = 79) was 3.8 %, 15.2 %, and 25.3 % for size cutoffs of 1-3, 1-5, and 1-10 mm polyps, respectively (P < 0.001). Surveillance interval agreements between pathology and optical diagnosis for the three groups were 97.2 %, 95.5 %, and 94.2 %, respectively. Total reductions in pathology examinations for the three groups were 33.5 %, 62.3 %, and 78.2 %, respectively. CONCLUSION : A 3-mm cutoff for clinical implementation of optical diagnosis resulted in a very low risk of delayed management of advanced neoplasia while showing high surveillance interval agreement with pathology and a one-third reduction in overall requirement for pathology examinations.

Automated Detection of Bowel Preparation Scoring and Adequacy With Deep Convolutional Neural Networks

INTRODUCTION

Adequate bowel preparation is integral to effective colonoscopy. Inadequate bowel preparation has been associated with reduced adenoma detection rate and increased post-colonoscopy colorectal cancer (PCCRC). As a result, the USMSTF recommends early interval reevaluation for colonoscopies with inadequate bowel preparation. However, bowel preparation documentation is highly variable with subjective interpretation. In this study, we developed deep convolutional neural networks (DCNN) to objectively ascertain bowel preparation.

METHODS

Bowel preparation scores were assigned using the Boston Bowel Preparation Scale (BBPS). Bowel preparation adequacy and inadequacy were defined as BBPS ≥2 and BBPS <2, respectively. A total of 38523 images were extracted from 28 colonoscopy videos and split into 26966 images for training, 7704 for validation, and 3853 for testing. Two DCNNs were created using a Densenet-169 backbone in PyTorch library evaluating BBPS score and bowel preparation adequacy. We used Adam optimiser with an initial learning rate of 3 × 10-4 and a scheduler to decay the learning rate of each parameter group by 0.1 every 7 epochs along with focal loss as our criterion for both classifiers.

RESULTS

The overall accuracy for BBPS subclassification and determination of adequacy was 91% and 98%, respectively. The accuracy for BBPS 0, BBPS 1, BBPS 2, and BBPS 3 was 84%, 91%, 85%, and 96%, respectively.

CONCLUSION

We developed DCCNs capable of assessing bowel preparation adequacy and scoring with a high degree of accuracy. However, this algorithm will require further research to assess its efficacy in real-time colonoscopy.