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

The Effect of Liposomal Diallyl Disulfide and Oxaliplatin on Proliferation of Colorectal Cancer Cells: In Vitro and In Silico Analysis

Diallyl disulfide (DADS) is one of the main bioactive organosulfur compounds of garlic, and its potential against various cancer models has been demonstrated. The poor solubility of DADS in aqueous solutions limits its uses in clinical application. The present study aimed to develop a novel formulation of DADS to increase its bioavailability and therapeutic potential and evaluate its role in combination with oxaliplatin (OXA) in the colorectal cancer system. We prepared and characterized PEGylated, DADS (DCPDD), and OXA (DCPDO) liposomes. The anticancer potential of these formulations was then evaluated in HCT116 and RKO colon cancer cells by different cellular assays. Further, a molecular docking-based computational analysis was conducted to determine the probable binding interactions of DADS and OXA. The results revealed the size of the DCPDD and DCPDO to be 114.46 nm (95% EE) and 149.45 nm (54% EE), respectively. They increased the sensitivity of the cells and reduced the IC₅₀ several folds, while the combinations of them showed a synergistic effect and induced apoptosis by 55% in the cells. The molecular docking data projected several possible targets of DADS and OXA that could be evaluated more precisely by these novel formulations in detail. This study will direct the usage of DCPDD to augment the therapeutic potential of DCPDO against colon cancer in clinical settings.

Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Comparing right colon adenoma detection rate during water exchange and air insufflation: a double-blind randomized controlled trial

BACKGROUND

Randomized controlled trials (RCTs) have reported that water exchange (WE) produced the highest adenoma detection rate (ADR) but did not evaluate right colon adenoma detection rate (rADR) as a primary outcome and only one of the trials employed blinded colonoscopists. The aim of our study was to determine whether, compared with air insufflation, WE significantly increases rADR and right colon serrated lesion detection rate (rSLDR) and decreases adenoma miss rate (rAMR).

METHODS

This prospective, double-blind RCT was conducted at a regional hospital in Taiwan between December 2015 and February 2020. Standard WE and air insufflation were performed. After cecal intubation, the second blinded endoscopist examined the right colon and obtained rADR (primary outcome) and rSLDR. Then, the primary colonoscopist reinserted the scope to the cecum with WE in both groups and performed a tandem examination of the right colon to obtain rAMR.

RESULTS

There were 284 patients (50.9% male, mean age 58.9 ± 9.4 years) who were randomized to WE (n = 144) or air insufflation (n = 140). The baseline characteristics were similar. The rADR (34.7% vs. 22.3%, p = 0.025), Boston Bowel Preparation Scale scores (mean, 2.6 ± 0.6vs. 2.2 ± 0.6, p < 0.001), rSLDR (18.1% vs. 7.1%, p = 0.007), and rAMR (31.5% vs. 45.2%, p = 0.038) were significantly different between WE and air insufflation.

CONCLUSIONS

The current study demonstrated a significantly higher rADR and rSLDR with the WE method performed by blinded colonoscopists. The impact of the significant findings in this report on the occurrence of interval cancers deserves to be studied.

Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Serrated Polyps and the Risk of Metachronous Colorectal Advanced Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Surveillance recommendations for serrated polyps (SPs) are based on insufficient evidence. We aimed to evaluate the risk of metachronous advanced colorectal neoplasia (ACRN) associated with SPs.

METHODS

We searched all relevant studies published through August 2020 that examined the risk of SPs for developing metachronous lesions. We performed meta-analyses of the risk of metachronous ACRN or colorectal cancer (CRC) between patients with SPs (or sessile serrated lesions [SSLs]) alone and those with conventional adenomas alone, and between patients with synchronous SPs (or SSLs) and conventional adenomas and those with conventional adenomas alone.

RESULTS

Eleven studies with 1,079,315 patients were included in the meta-analysis. No significant differences in the risks of metachronous ACRN and CRC were found between the SPs alone and conventional adenomas alone groups (odds ratio [OR] [95% confidence interval [CI]]: ACRN, 0.70 [0.27-1.82]; CRC, 0.74 [0.47-1.14]). The risks were similar between SSLs alone and conventional adenomas alone (OR [95% CI]: ACRN, 0.91 [0.23-3.63]; CRC, 1.11 [0.42-2.97]). Significant heterogeneity was identified in these comparisons. Synchronous SPs (or SSLs) and high-risk adenomas (HRAs) had a higher risk of metachronous ACRN than HRAs alone (OR [95% CI]: SPs+HRAs, 1.64 [1.21-2.24]; SSLs+HRAs, 3.10 [1.92-4.99]); however, there was no difference in the risk between synchronous SPs (or SSLs) and low-risk adenomas and low-risk adenomas alone.

CONCLUSIONS

The results of this meta-analysis support the current guidelines, which recommend similar surveillance intervals for SSLs and conventional adenomas. Patients with synchronous SPs (or SSLs) and HRAs appear to be at an increased risk of metachronous ACRN, and further studies are needed to determine whether they require more intensive surveillance.

Updates on age to start and stop colorectal cancer screening: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Colorectal Cancer Screening - Approach, Evidence, and Future Directions

Colorectal Cancer ScreeningScreening for colorectal cancer is widespread and successful but screening programs across the globe differ in their recommendations. In this article, Helsingen and Kalager review the evidence for different approaches to colorectal cancer screening and propose a framework for the evaluation of screening programs going forward.

Definition of competence standards for optical diagnosis of diminutive colorectal polyps: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

BACKGROUND : The European Society of Gastrointestinal Endoscopy (ESGE) has developed a core curriculum for high quality optical diagnosis training for practice across Europe. The development of easy-to-measure competence standards for optical diagnosis can optimize clinical decision-making in endoscopy. This manuscript represents an official Position Statement of the ESGE aiming to define simple, safe, and easy-to-measure competence standards for endoscopists and artificial intelligence systems performing optical diagnosis of diminutive colorectal polyps (1 - 5 mm). METHODS : A panel of European experts in optical diagnosis participated in a modified Delphi process to reach consensus on Simple Optical Diagnosis Accuracy (SODA) competence standards for implementation of the optical diagnosis strategy for diminutive colorectal polyps. In order to assess the clinical benefits and harms of implementing optical diagnosis with different competence standards, a systematic literature search was performed. This was complemented with the results from a recently performed simulation study that provides guidance for setting alternative competence standards for optical diagnosis. Proposed competence standards were based on literature search and simulation study results. Competence standards were accepted if at least 80 % agreement was reached after a maximum of three voting rounds. RECOMMENDATION 1:  In order to implement the leave-in-situ strategy for diminutive colorectal lesions (1-5 mm), it is clinically acceptable if, during real-time colonoscopy, at least 90 % sensitivity and 80 % specificity is achieved for high confidence endoscopic characterization of colorectal neoplasia of 1-5 mm in the rectosigmoid. Histopathology is used as the gold standard.Level of agreement 95 %. RECOMMENDATION 2:  In order to implement the resect-and-discard strategy for diminutive colorectal lesions (1-5 mm), it is clinically acceptable if, during real-time colonoscopy, at least 80 % sensitivity and 80 % specificity is achieved for high confidence endoscopic characterization of colorectal neoplasia of 1-5 mm. Histopathology is used as the gold standard.Level of agreement 100 %. CONCLUSION : The developed SODA competence standards define diagnostic performance thresholds in relation to clinical consequences, for training and for use when auditing the optical diagnosis of diminutive colorectal polyps.

The impact of cumulative colorectal cancer screening delays: A simulation study

OBJECTIVE

Annual fecal immunochemical tests can reduce colorectal cancer incidence and mortality. However, screening is a multi-step process and most patients do not perfectly adhere to guideline-recommended screening schedules. Our objective was to compare the reduction in colorectal cancer incidence and life-years gained based on US guideline-concordant fecal immunochemical test screening to scenarios with a range of delays.

METHOD

The Colorectal Cancer Simulated Population model for Incidence and Natural history (CRC-SPIN) microsimulation model was used to estimate the effect of systematic departures from fecal immunochemical test screening guidelines on lifetime screening benefit.

RESULTS

The combined effect of consistent modest delays in screening initiation (1 year), repeated fecal immunochemical test screening (3 months), and receipt of follow-up or surveillance colonoscopy (3 months) resulted in up to 1.3 additional colorectal cancer cases per 10,000, 0.4 additional late-stage colorectal cancer cases per 10,000 and 154.7 fewer life-years gained per 10,000. A 5-year delay in screening initiation had a larger impact on screening effectiveness than consistent small delays in repeated fecal immunochemical test screening or receipt of follow-up colonoscopy after an abnormal fecal immunochemical test. The combined effect of consistent large delays in screening initiation (5 years), repeated fecal immunochemical test screening (6 months), and receipt of follow-up or surveillance colonoscopy (6 months) resulted in up to 3.7 additional colorectal cancer cases per 10,000, 1.5 additional late-stage colorectal cancer cases per 10,000 and 612.3 fewer life-years gained per 10,000.

CONCLUSIONS

Systematic delays across the screening process can result in meaningful reductions in colorectal cancer screening effectiveness, especially for longer delays. Screening delays could drive differences in colorectal cancer incidence across patient groups with differential access to screening.

AGA Clinical Practice Update on Surveillance After Pathologically Curative Endoscopic Submucosal Dissection of Early Gastrointestinal Neoplasia in the United States: Commentary

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update was to review the available evidence and provide expert advice regarding surveillance using endoscopy and other relevant modalities after removal of dysplastic lesions and early gastrointestinal cancers with endoscopic submucosal dissection deemed to be pathologically curative. This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors, who are advanced endoscopists with high-level expertise in performing endoscopic submucosal dissection to treat dysplasia and early cancers in the luminal gastrointestinal tract.

Age-Specific Rates and Time-Courses of Gastrointestinal and Nongastrointestinal Complications Associated With Screening/Surveillance Colonoscopy

INTRODUCTION

The rates of serious cardiac, neurologic, and pulmonary events attributable to colonoscopy are poorly characterized, and background event rates are usually not accounted for.

METHODS

We performed a multistate population-based study using changepoint analysis to determine the rates and timing of serious gastrointestinal and nongastrointestinal adverse events associated with screening/surveillance colonoscopy, including analyses by age (45 to <55, 55 to <65, 65 to <75, and ≥75 years). Among 4.5 million persons in the Ambulatory Surgery and Services Databases of California, Florida, and New York who underwent screening/surveillance colonoscopy in 2005-2015, we ascertained serious postcolonoscopy events in excess of background rates in Emergency Department (SEDD) and Inpatient Databases (SID).

RESULTS

Most serious nongastrointestinal postcolonoscopy events were expected based on the background rate and not associated with colonoscopy itself. However, associated nongastrointestinal events predominated over gastrointestinal events at ages ≥65 years, including more myocardial infarctions plus ischemic strokes than perforations at ages ≥75 years (361 [95% confidence intervals {CI} 312-419] plus 1,279 [95% CI 1,182-1,384] vs 912 [95% CI 831-1,002] per million). At all ages, the observed-to-expected ratios for days 0-7, 0-30, and 0-60 after colonoscopy were substantially >1 for gastrointestinal bleeding and perforation, but minimally >1 for most nongastrointestinal complications. Risk periods ranged from 1 to 125 days depending on complication type and age. No excess postcolonoscopy in-hospital deaths were observed.

DISCUSSION

Although crude counts substantially overestimate nongastrointestinal events associated with colonoscopy, nongastrointestinal complications exceed bleeding and perforation risk in older persons. The inability to ascertain modifications to antiplatelet therapy was a study limitation. Our results can inform benefit-to-risk determinations for preventive colonoscopy.

Post-polypectomy colonoscopy surveillance: Can we improve the diagnostic yield?

Although adenomas and serrated polyps are the preneoplastic lesions of colorectal cancer, only few of them will eventually progress to cancer. This review provides a comprehensive overview of the present and future of post-polypectomy colonoscopy surveillance. Post-polypectomy surveillance guidelines have recently been updated and all share the aim towards more selective and less frequent surveillance. We have examined these current guidelines and compared the recommendations of each of them. To improve the diagnostic yield of post-polypectomy surveillance it is important to find predictors of metachronous polyps that better identify high-risk individuals of developing advanced neoplasia. For this reason, we have also conducted a literature review of the molecular biomarkers of metachronous advanced colorectal polyps. Finally, we have discussed future directions of post-polypectomy surveillance and identified possible strategies to improve the use of endoscopic resources with the COVID-19 pandemic.

Proliferation, apoptosis and their regulatory protein expression in colorectal adenomas and serrated lesions

BACKGROUND

Adenomas and serrated lesions represent heterogeneous sets of early precursors in the colorectum with varying malignant potential. They are often distinguished by their histopathologic differences, but little is known about potential differences in regulation of epithelial proliferation and apoptosis.

METHODS

We conducted a protein expression analysis using tissue microarrays of 625 colorectal adenomas and 142 serrated lesions to determine potential differences in regulation of epithelial proliferation and apoptosis. We quantitated proliferation with Ki-67; apoptosis with activated caspase-3 (CASP3); up- and down-regulators of proliferation with cyclin D1, p16INK2, and p21Cip1; and apoptosis regulators with BAX, BCL2, and survivin. Linear mixed effects models and circos diagrams were used to determine relationships among expression and lesion characteristics.

RESULTS

Adenomas had a significantly higher CASP-3 labeling index (LI) than serrated lesions, resulting in a lower net growth ratio (Ki-67 LI/activated CASP-3 LI, p-value<0.0001). Cyclin D1 LI, p16 LI and p21 LI were lower in adenomas compared to serrated lesions, while expression of both BCL2 and BAX were higher (p <0.001). Among adenomas, cyclin D1 LI and p16 LI levels increased with greater villous component, and the highest BAX expression was detected in adenomas larger than 2 cm (both p<0.0001). Right-sided adenomas had higher CASP3 LI than left colorectal adenomas (p = 0.008). Significant differences in cyclin D1 LI, p21 LI and survivin LI were also observed across histopathologic subtypes of serrated lesions.

CONCLUSIONS

Our findings demonstrate different patterns of regulatory protein expression in adenomas than serrated lesions, especially involving apoptosis. ClinicalTrials.gov Identifier: NCT00272324.

Evaluation of an Artificial Intelligence-Augmented Digital System for Histologic Classification of Colorectal Polyps

Importance

Colorectal polyps are common, and their histopathologic classification is used in the planning of follow-up surveillance. Substantial variation has been observed in pathologists' classification of colorectal polyps, and improved assessment by pathologists may be associated with reduced subsequent underuse and overuse of colonoscopy.

Objective

To compare standard microscopic assessment with an artificial intelligence (AI)-augmented digital system that annotates regions of interest within digitized polyp tissue and predicts polyp type using a deep learning model to assist pathologists in colorectal polyp classification.

Design, Setting, and Participants

In this diagnostic study conducted at a tertiary academic medical center and a community hospital in New Hampshire, 100 slides with colorectal polyp samples were read by 15 pathologists using a microscope and an AI-augmented digital system, with a washout period of at least 12 weeks between use of each modality. The study was conducted from February 10 to July 10, 2020.

Main Outcomes and Measures

Accuracy and time of evaluation were used to compare pathologists' performance when a microscope was used with their performance when the AI-augmented digital system was used. Outcomes were compared using paired t tests and mixed-effects models.

Results

In assessments of 100 slides with colorectal polyp specimens, use of the AI-augmented digital system significantly improved pathologists' classification accuracy compared with microscopic assessment from 73.9% (95% CI, 71.7%-76.2%) to 80.8% (95% CI, 78.8%-82.8%) (P < .001). The overall difference in the evaluation time per slide between the digital system (mean, 21.7 seconds; 95% CI, 20.8-22.7 seconds) and microscopic examination (mean, 13.0 seconds; 95% CI, 12.4-13.5 seconds) was -8.8 seconds (95% CI, -9.8 to -7.7 seconds), but this difference decreased as pathologists became more familiar and experienced with the digital system; the difference between the time of evaluation on the last set of 20 slides for all pathologists when using the microscope and the digital system was 4.8 seconds (95% CI, 3.0-6.5 seconds).

Conclusions and Relevance

In this diagnostic study, an AI-augmented digital system significantly improved the accuracy of pathologic interpretation of colorectal polyps compared with microscopic assessment. If applied broadly to clinical practice, this tool may be associated with decreases in subsequent overuse and underuse of colonoscopy and thus with improved patient outcomes and reduced health care costs.

Comparison of Right Colon Adenoma Miss Rates Between Water Exchange and Carbon Dioxide Insufflation: A Prospective Randomized Controlled Trial

GOALS

To test the hypothesis that water exchange (WE), when compared with carbon dioxide (CO2) insufflation, significantly reduces the right colon adenoma miss rate (rAMR) in a blinded randomized controlled trial with cap-assisted colonoscopy.

BACKGROUND

The unblinded consecutive group observational data showed that WE significantly decreased rAMR. The unblinded data are limited by potential bias.

STUDY

Consecutive patients aged 45 years or more were randomized to undergo insertion with WE or CO2. Withdrawal and polypectomy were performed with CO2 in both groups to the hepatic flexure. The colonoscope was reinserted to the cecum. A second colonoscopist re-examined the right colon. The second colonoscopist was unaware, but made a guess, of the initial insertion method. The number of additional adenomas divided by the total number detected in both examinations equaled rAMR.

RESULTS

Among 262 patients (131/group), demographic variables were similar. The body mass index was significantly higher in the WE group. Compared with CO2, WE significantly decreased rAMR [18.0% (33/183) vs. 34.6% (62/179), P=0.0025] and right colon serrated polyp miss rate [17.4% (27/155) vs. 39.3% (33/84), P=0.002]. Multivariate logistic regression analysis showed that WE was an independent predictor of rAMR (odds ratio, 0.42; 95% confidence interval, 0.21-0.86), and so was ≥2 adenomas in the right colon (odds ratio, 2.35; 95% confidence interval, 1.17-4.76). Whether the second colonoscopist guessed the insertion method correctly or not, and demographic and procedure variables were not associated with rAMR.

CONCLUSIONS

The randomized controlled trial validated unblinded observational data showing that WE significantly decreased rAMR and right colon serrated polyp miss rate (clinical trial registration number: NCT03845933).

Systematic review with meta-analysis: the prevalence of post-colonoscopy colorectal cancers using the World Endoscopy Organization nomenclature

INTRODUCTION

Post-colonoscopy colorectal cancers (PCCRCs) have been proposed as a performance metric for colonoscopy quality assurance programs. Previously, there was no standardised terminology or reporting methods. In 2018, the World Endoscopy Organization (WEO) advised standardised definitions and prevalence calculation methodology.

AIMS

To assess PCCRC burden using WEO standardised methods, to explore causes of heterogeneity, and to review changes in prevalence over time METHODS: We updated a prior systematic review by searching Ovid MEDLINE and EMBASE databases from 1 January 2013 to 31 January 2021 to identify population-based studies (or multicentre studies representative of the local population) reporting PCCRC prevalence (PROSPERO [CRD42020183796]). Two authors independently determined study eligibility, assessed quality, and extracted data. We estimated the PCCRC 3-year prevalence using WEO-recommended methodologies and investigated between-study sources of heterogeneity. We examined changes in prevalence over time.

RESULTS

Fifteen studies reporting on 25 872 PCCRC cases met eligibility criteria. Pooled PCCRC 3 year prevalence was 8.2% (95% CI = 6.9%-9.4%, I²  = 98.2%) across four European studies using WEO precise methodology. Proximal PCCRC prevalence was greater than distal (9.7% [95% CI = 7.0%-12.4%] vs 5.4% [95% CI = 2.9%-7.8%], I²  = 99.2%). Seven studies reporting PCCRC rates over time showed no consistent trend: four showed a decrease, one an increase and two were unchanged. Between-study heterogeneity was high.

CONCLUSIONS

Pooled 3-year PCCRC prevalence was 8.2% (95% CI = 6.9%-9.4%). Despite WEO standardised methodology to define and calculate PCCRC rates, there was significant heterogeneity among studies. Comparing rates between populations remains challenging and additional studies are needed to better understand the global PCCRC burden to inform quality assurance programs.

Linked color imaging, mucosal exposure device, their combination, and standard colonoscopy for adenoma detection: a randomized trial

BACKGROUND AND AIMS

By different mechanisms, image-enhancement techniques (linked color imaging [LCI]) and mucosal exposure devices (Endocuff-assisted colonoscopy [EAC]) can improve the adenoma detection rate (ADR) during screening colonoscopy. The impact of the combination of the 2 techniques has never been studied. This study aimed to compare the ADR between the combination of LCI and EAC (LCI+EAC), LCI alone, EAC alone, and standard high-definition (HD) colonoscopy.

METHODS

This prospective randomized controlled trial included participants who underwent screening colonoscopy. Participants were randomized to LCI+EAC, LCI, EAC, and standard HD colonoscopy. All colonoscopies were performed by endoscopists with a recorded ADR ≥35%. The primary outcome was the ADR. Secondary outcomes were proximal ADR (pADR) and the mean number of adenomas per colonoscopy (APC).

RESULTS

One thousand participants were included in the study. The LCI+EAC group provided the highest ADR and pADR. The ADRs in the LCI+EAC, LCI, EAC, and standard HD colonoscopy groups were 57.2%, 52.8%, 51.6%, and 47.6%, respectively, with pADRs of 38.4%, 34.8%, 33.6%, and 28.0%, respectively. The mean numbers of APC were 1.28, 1.20, 1.16, and .89, respectively. After a multiple comparison adjustment, a significant difference in pADR was only observed between the LCI+EAC and standard HD colonoscopy groups (difference, 10.3 percentage points; 95% confidence interval, .02%-17.4%; P = .05). The incidence rate ratios of the adenoma numbers were significantly higher in the LCI+EAC (1.43), LCI (1.34), and EAC (1.30) groups relative to the standard HD colonoscopy group (.89) (P < .009 for all comparisons).

CONCLUSIONS

The combination of LCI and EAC can significantly improve the detection of pADR and APC but not ADR by high-ADR performers. (Clinical trial registration number: TCTR20190319001.).

Risk Factors for High-Risk Adenoma on the First Lifetime Colonoscopy Using Decision Tree Method: A Cross-Sectional Study in 6,047 Asymptomatic Koreans

Background/Aims: As risk of colorectal neoplasm is varied even in persons with “average-risk,” risk evaluation and tailored screening are needed. This study aimed to evaluate the risk factors of high-risk adenoma (HRA) in healthy individuals and determine the characteristics of advanced neoplasia (AN) among individual polyps.

Methods: Asymptomatic adults who underwent the first lifetime screening colonoscopy at the Seoul National University Hospital Healthcare System Gangnam Center (SNUH GC) were recruited from 2004 to 2007 as SNUH GC Cohort and were followed for 10 years. Demographic and clinical characteristics were compared between the subjects with and without AN (≥10 mm in size, villous component, and/or high-grade dysplasia and/or cancer) or HRA (AN and/or 3 or more adenomas). For individual polyps, correlations between clinical or endoscopic features and histologic grades were evaluated using a decision tree method.

Results: A total of 6,047 subjects were included and 5,621 polyps were found in 2,604 (43%) subjects. Advanced age, male sex, and current smoking status were statistically significant with regards to AN and HRA. A lower incidence of AN was observed in subjects taking aspirin. In the decision tree model, the location, shape, and size of the polyp, and sex of the subject were key predictors of the pathologic type. A weak but significant association was observed between the prediction of the final tree and the histological grouping (Kendall's tau-c = 0.142, p < 0001).

Conclusions: Advanced neoplasia and HRA can be predicted using several individual characteristics and decision tree models.

A Surveillance Endoscopy Strategy Based on Local Recurrence Rates after Colorectal Endoscopic Submucosal Dissection

Backgrounds: It is not clear when and how frequently surveillance endoscopy should be performed after colorectal endoscopic submucosal dissection (ESD). We aimed to suggest a surveillance endoscopy strategy by investigating the cumulative local recurrence rates and identifying risk factors for local recurrence after colorectal ESD. Methods: We reviewed the medical records of 770 patients who underwent colorectal ESD for 778 lesions at our institution from 2005 to 2016. We investigated the cumulative local recurrence rates and risk factors for local recurrence. Results: Local recurrence developed in 12 (1.5%) of 778 lesions during the follow-up period of 37.4 ± 31.7 months. The one-, three-, and five-year cumulative local recurrence rates were 0.4%, 1.7%, and 2.2%, respectively. The risk factors for local recurrence were piecemeal resection (odds ratio (OR) 3.948, 95% confidence interval (CI) 1.164–13.385; p = 0.028) and histological incomplete resection (OR 8.713, 95% CI 2.588–29.334; p < 0.001). Local recurrence tended to develop frequently after ESD of early cancers. Conclusions: Short-term surveillance endoscopy should be recommended after piecemeal ESD, histological incomplete resection, and ESD of early colorectal cancers. Surveillance endoscopy with longer intervals can be suggested after en bloc ESD with the histological complete resection of benign colorectal tumors.

Long-term risk of colorectal cancer after removal of adenomas during screening colonoscopies in a large community-based population in China

Patients with conventional adenoma removal are recommended to undergo colonoscopy surveillance to prevent colorectal cancer (CRC). However, evidence supporting the guidelines of colonoscopy surveillance is limited, especially among the Chinese population. We investigated the association between colonoscopy adenoma findings and CRC risk among individuals aged 40 to 74 years who underwent baseline colonoscopy from 2007 to 2016 in Jiashan and Haining, Zhejiang, China; 34 382 participants were categorized into advanced adenoma, nonadvanced adenoma and no adenoma based on adenoma findings. A multivariable Cox regression model was used to estimate the hazard ratio (HR) of CRC incidence with adjustment for potential confounding factors. After a median follow-up time of 7.7 years, 113 incident cases of CRC were identified (18 occurred in 1632 participants with advanced adenoma, 16 in 3973 participants with nonadvanced adenoma and 79 in 28 777 participants with no adenoma). Compared to no adenoma group, the adjusted HR for CRC in advanced adenoma group was 4.01 (95% CI, 2.37-6.77). For nonadvanced adenomas, individuals with ≥3 adenomas showed an increased risk of CRC (HR, 3.65; 95% CI, 1.43-9.31), but no significantly increased risk of CRC was found for 1 to 2 nonadvanced adenomas, compared to those with no adenoma. Our study suggested that the risk of subsequent CRC increased in individuals with high-risk adenoma (at least one advanced adenoma or ≥3 nonadvanced adenomas), but not in those with 1 to 2 nonadvanced adenomas. These results provide the first evidence from the Chinese population for the current surveillance guidelines.

Guidance for setting easy-to-adopt competence criteria for optical diagnosis of diminutive colorectal polyps: a simulation approach

BACKGROUND AND AIMS

One reason the optical diagnosis strategy for diminutive colorectal polyps has not yet been implemented is that the current competence criteria (Preservation and Incorporation of Valuable Endoscopic Innovation [PIVI] initiative) are difficult to use in daily practice. To provide guidance for setting alternative easy-to-adopt competence criteria, we determined the lowest proportion of diminutive polyps that should have a correct optical diagnosis to meet the PIVI.

METHODS

For this simulation study, we used datasets from 2 prospectively collected cohorts of patients who underwent colonoscopy in either a primary colonoscopy or fecal immunochemical test (FIT) screening setting. In the simulation approach, virtual endoscopists or computer-aided diagnosis systems performed optical diagnosis of diminutive polyps with a fixed diagnostic performance level (strategy) on all individuals in the cohort who had ≥1 diminutive polyp. Strategies were defined by systematically varying the proportion of correct optical diagnoses for each polyp subtype (ie, adenomas, hyperplastic polyps, sessile serrated lesions). For each strategy, we determined whether PIVI-1 (≥90% agreement with U.S. or European Society for Gastrointestinal Endoscopy [ESGE] surveillance guidelines) and PIVI-2 (≥90% negative predictive value [NPV] for neoplastic lesions in the rectosigmoid) were met using Monte Carlo sampling with 1000 repetitions, with histology as reference.

RESULTS

The level of overall diagnostic accuracy to achieve the PIVI differed significantly depending on the clinical setting and guidelines used. In the colonoscopy screening setting, all diagnostic strategies in which 92% of all diminutive polyps (regardless of histology) were diagnosed correctly led to 90% or more agreement with U.S. surveillance intervals (ie, PIVI-1). For all diagnostic strategies in which ≥89% of all diminutive polyps were correctly diagnosed, at least 90% NPV was achieved (ie, PIVI-2). For the FIT screening setting, values were respectively ≥77% and ≥94%. When using ESGE guidelines, PIVI-1 was in both settings already met when 40% of all diminutive polyps were diagnosed correctly.

CONCLUSIONS

In contrast to the fixed PIVI criteria, our simulation study shows that different thresholds for the proportion of correctly diagnosed diminutive polyps lead to different clinical consequences depending on guidelines and clinical setting. However, this target proportion of diminutive colorectal polyps correctly diagnosed with optical diagnosis represents easier-to-adopt competence criteria.

Artificial intelligence-assisted colonoscopy: A prospective, multicenter, randomized controlled trial of polyp detection

BACKGROUND

Artificial intelligence (AI) assistance has been considered as a promising way to improve colonoscopic polyp detection, but there are limited prospective studies on real-time use of AI systems.

METHODS

We conducted a prospective, multicenter, randomized controlled trial of patients undergoing colonoscopy at six centers. Eligible patients were randomly assigned to conventional colonoscopy (control group) or AI-assisted colonoscopy (AI group). AI assistance was our newly developed AI system for real-time colonoscopic polyp detection. Primary outcome is polyp detection rate (PDR). Secondary outcomes include polyps per positive patient (PPP), polyps per colonoscopy (PPC), and non-first polyps per colonoscopy (PPC-Plus).

RESULTS

A total of 2352 patients were included in the final analysis. Compared with the control, AI group did not show significant increment in PDR (38.8% vs. 36.2%, p = 0.183), but its PPC-Plus was significantly higher (0.5 vs. 0.4, p < 0.05). In addition, AI group detected more diminutive polyps (76.0% vs. 68.8%, p < 0.01) and flat polyps (5.9% vs. 3.3%, p < 0.05). The effects varied somewhat between centers. In further logistic regression analysis, AI assistance independently contributed to the increment of PDR, and the impact was more pronounced for male endoscopists, shorter insertion time but longer withdrawal time, and elderly patients with larger waist circumference.

CONCLUSION

The intervention of AI plays a limited role in overall polyp detection, but increases detection of easily missed polyps; ChiCTR.org.cn number, ChiCTR1800015607.

Fecal Fusobacterium nucleatum as a predictor for metachronous colorectal adenoma after endoscopic polypectomy

BACKGROUND AND AIM

Fusobacterium nucleatum is increasingly being recognized as an important risk factor in colorectal cancer and colorectal adenoma. Endoscopic polypectomy is associated with a decreased incidence of colorectal cancer; however, patients still suffer from a risk of metachronous adenoma. Currently, there are few effective non-invasive factors that may predict metachronous colorectal adenoma. Here, we evaluated the performance of F. nucleatum in predicting metachronous adenoma.

METHODS

Fecal samples and clinical information of patients before endoscopic polypectomy were collected from 367 patients in a retrospective cohort, and 238 patients in a prospective cohort. The abundance of fecal F. nucleatum was measured via quantitative polymerase chain reaction. Surveillance colonoscopies were conducted between 1 and 3 years after polypectomy (average follow-up 27.07 months for the retrospective cohort & 22.57 months for the prospective cohort) to identify metachronous adenoma. Candidate predictive factors and cut-off value of F. nucleatum abundance were identified from the retrospective cohort and then validated in the prospective cohort.

RESULTS

A high abundance of fecal F. nucleatum was found to be an independent risk factor for metachronous adenomas (odds ratio, 6.38; P < 0.001) in the retrospective cohort and was validated in the prospective cohort with a specificity of 65.00%, and a sensitivity of 73.04%, and an overall performance with the area under the curve of 0.73.

CONCLUSION

Fecal abundance of F. nucleatum may be a reliable predictor for metachronous adenoma after endoscopic polypectomy.

Recurrence of Colorectal Neoplastic Polyps After Incomplete Resection

BACKGROUND

Incomplete resection of neoplastic polyps is considered an important reason for the development of colorectal cancer. However, there are no data on the natural history of polyps that were incompletely removed.

OBJECTIVE

To examine the risk for metachronous neoplasia during surveillance colonoscopy after documented incomplete polyp resection.

DESIGN

Observational cohort study of patients who participated in the CARE (Complete Adenoma REsection) study (2009 to 2012).

SETTING

2 academic medical centers.

PATIENTS

Patients who had resection of a 5- to 20-mm neoplastic polyp, had a documented complete or incomplete resection, and had a surveillance examination.

MEASUREMENTS

Segment metachronous neoplasia, defined as the proportion of colon segments with at least 1 neoplastic polyp at first surveillance examination, was measured. Segment metachronous neoplasia was compared between segments with a prior incomplete polyp resection (incomplete segments) and those with a prior complete resection (complete segments), accounting for clustering of segments within patients.

RESULTS

Of 233 participants in the original study, 166 (71%) had at least 1 surveillance examination. Median time to surveillance was shorter after incomplete versus complete resection (median, 17 vs. 45 months). The risk for any metachronous neoplasia was greater in segments with incomplete versus complete resection (52% vs. 23%; risk difference [RD], 28% [95% CI, 9% to 47%]; P = 0.004). Incomplete segments also had a greater number of neoplastic polyps (mean, 0.8 vs. 0.3; RD, 0.50 [CI, 0.1 to 0.9]; P = 0.008) and greater risk for advanced neoplasia (18% vs. 3%; RD, 15% [CI, 1% to 29%]; P = 0.034). Incomplete resection was the strongest independent factor associated with metachronous neoplasia (odds ratio, 3.0 [CI, 1.12 to 8.17]).

LIMITATION

Potential patient selection bias due to incomplete follow-up.

CONCLUSION

This natural history study found a statistically significantly greater risk for future neoplasia and advanced neoplasia in colon segments after incomplete resection compared with segments with complete resection.

PRIMARY FUNDING SOURCE

None.

Early-Age Onset Colorectal Neoplasia in Average-Risk Individuals Undergoing Screening Colonoscopy: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Incidence and mortality associated with early-age onset colorectal cancer (EAO-CRC) is increasing, prompting professional society recommendations to lower the screening age in average-risk individuals. The yield of screening individuals younger than 50 years is not known.

METHODS

A systematic review of 3 databases from inception through July 2020 was performed in all languages that reported colonoscopy findings in average-risk individuals younger than 50 years. The primary outcomes were EAO colorectal neoplasia (CRN) and advanced colorectal neoplasia (aCRN) prevalence. Subgroup analyses were performed based on sex, geographic location, time period, and age, including comparison with those aged 50-59 years. Generalized linear mixed model with random intercept logistic regression and fixed subgroup effects were performed.

RESULTS

Of 10,123 unique articles, 17 studies published between 2002 and 2020, including 51,811 average-risk individuals from 4 continents, were included. The pooled rate of EAO-CRN was 13.7% (95% confidence interval [CI], 0.112%-0.168%) and EAO-aCRN was 2.2% (95% CI, 0.016%-0.031%). Prevalence of CRC was 0.05% (95% CI, 0.00029%-0.0008%). Rates of EAO-CRN were higher in men compared with women (relative risk, 1.71%; 95% CI, 1.49%-1.98%), and highest in the United States (15.6%; 95% CI, 12.2%-19.7%) compared with Europe (14.9%; 95% CI, 6.9%-29.3%), East Asia (13.4%; 95% CI, 10.3%-17.2%), and the Middle East (9.8%; 95% CI, 7.8%-12.2%) (P = .04) The rate of EAO-CRN in age groups 45-49 years and 50-59 years was 17.8% (95% CI, 14.5%-21.6%) and 24.8% (95% CI, 19.5%-30.8%), respectively (P = .04). The rate of EAO-aCRN in age group 45-49 years was 3.6% (95% CI, 1.9%-6.7%) and 4.2% (95% CI, 3.2%-5.7%), respectively (P = .69).

CONCLUSIONS

The rate of aCRN in individuals aged 45-49 years was similar to the rate observed in individual aged 50-59 years, suggesting that expanding screening to this population could yield a similar impact on colorectal cancer risk reduction.

Clinical practice standards for colonoscopy

Colonoscopy is considered as the most effective tool for preventing, screening, and diagnosing colorectal lesions. Effectiveness of colonoscopy was identified as a major priority, and it strictly depends on quality measures. Therefore, international guidelines were formulated on quality indicators for colonoscopy, aiming to reduce the rate of interval cancers related to missed lesions during colonoscopy. Quality indicators are divided into 3 time periods: preprocedure, intraprocedure, and postprocedure.  The main pre-procedural indicators are the assessment of the appropriateness of indication of colonoscopy and the prescription of adequate bowel preparation during a consultation prior to colonoscopy. Per-procedural criteria include all technical aspects of the procedure, which are "endoscopist-dependent" factors, particularly cecal intubation, detection of adenomas and withdrawal time. The main post-procedure indicators are the rate of complications, patient experience and optimal surveillance intervals following removal of colorectal polyps. The implementation of key performance measures in endoscopy practice is increasingly important as it can help improving our care of patients and optimize outcomes. In this review, the "Club d'endoscopie digestive" (CED) presented a summary of the main colonoscopy quality indicators, and suggested recommendations that took into account the particularities of our local conditions.

Nomograms to predict cancer-specific mortality in colon adenocarcinoma with different types of villous architecture

PURPOSE

The role of villous architecture in the prognosis of colon adenocarcinoma remains unclear. This study aimed to investigate the prognostic factors of colon adenocarcinoma with different types of villous architecture and to establish nomograms for predicting cancer-specific mortality.

METHODS

This retrospective study included 10,427 patients with colon adenocarcinoma arising in adenomas with villous architectures. The patients were stratified into the tubulovillous adenocarcinoma cohort and villous adenocarcinoma cohort. The prognostic risk factors, which were incorporated into nomograms for survival prediction, were determined by the log-rank test and Cox hazard models. The Harrell's Concordance Index (C-index) and calibration curve were utilized to evaluate the prediction accuracy.

RESULTS

The pathological type of villous architecture was independently associated with the mortality of the entire population. Age, race, tumor size, T/N/M stage, and chemotherapy were independent risk factors of mortality in both cohorts. Interestingly, tumor differentiation was a prognostic factor for tubulovillous adenocarcinoma rather than villous adenocarcinoma, while the retrieved lymph node number was a prognostic factor for villous adenocarcinoma rather than tubulovillous adenocarcinoma. Survival analysis showed that the mortality rate of villous adenocarcinoma was higher than that of tubulovillous adenocarcinoma (HR 1.361, P < 0.001). We then established nomograms to predict the mortality of both cohorts and found excellent discrimination and predictive accuracy (C-index 0.842 and 0.821).

CONCLUSION

Villous architecture is a determinant of colon adenocarcinoma outcomes, which might prompt reports of villous architecture in colon adenocarcinoma specimens by pathologists. Our population-based nomograms could be useful for predicting the survival of patients with colon adenocarcinoma and guiding individualized treatments.

Incorporating image enhanced endoscopy in your everyday practice

PURPOSE OF REVIEW

The purpose of this review is to analyze newly available image enhanced endoscopic techniques and to evaluate how these techniques can be integrated into daily routine.

RECENT FINDINGS

Recent guidelines have clearly stated how competency can be achieved. Endoscopist should have achieved general competence in endoscopy (more than 300 examinations) before commencing training in optical diagnosis.

SUMMARY

A validated optical diagnosis training course should be attended and meeting competence thresholds by assessing a minimum number of lesions prospectively during real-time endoscopy should be performed.These guidelines will help to standardize training and to achieve high efficiency in enhanced imaging.

Bowel preparation with 1L polyethylene glycol and ascorbate NER1006 doubles the chance to detect three or more adenomas in overweight or obese males

Background and study aims  Men have more colon cleansing failures, colorectal adenomas, and colorectal cancers than women. We analyzed whether 1-liter (1 L) polyethylene glycol (PEG) NER1006 improves high-quality (HQ) colon cleansing and adenoma detection in males versus two mid-volume alternatives. Patients and methods  The analysis of 1028 adult patients in two randomized clinical trials was performed. Adenoma detection and HQ cleansing were compared for overnight split dosing regimens with NER1006 (n = 513) versus combined oral sulfate solution or 2 L PEG + ascorbate (OSS/2 L PEG) (n = 515). Analyses included males versus females, overweight or obese (OO) males versus lean males, and NER1006 versus OSS/2 L PEG. In male patients, the adenoma detection rate of at least 3 (ADR3 +) was predicted with multiple logistic regression and statistical comparisons used the two-sided t-test. Results  ADR3 + was greater in males versus females (10.7 % [56/524] versus 5.8 % [29/504]; P = 0.004) despite comparable adequate cleansing success rates (93.2 % [479/514] versus 93.0 % [466/501]; P = 0.912) and more HQ-scores in females (41.6 % [1069/2570] versus 45.3 % [1134/2505]; P = 0.008). ADR was almost twice as high in OO versus lean males (43.4 % [184/424] versus 23.1 % [21/91]; P < 0.001). Multivariate logistic regression predicted ADR3 + detection to be twice as likely in OO males using NER1006 versus OSS/2 L PEG (odds ratio (95 % confidence interval [CI]) = 2.049 (1.082-3.973); P = 0.030) and 90 % more likely in all males (1.902 (1.045-3.526); P = 0.037). In males, including OO males, NER1006 attained more HQ-scores per trial than OSS or 2 L PEG (P ≤ 0.017 for all comparisons). Conclusions  NER1006 predicted the detection of more males for frequent surveillance than OSS/2 L PEG.

Risk stratification for colorectal cancer in individuals with subtypes of serrated polyps

OBJECTIVE

The longitudinal risk of colorectal cancer (CRC) associated with subtypes of serrated polyps (SPs) remains incompletely understood.

DESIGN

This community-based, case-control study included 317 178 Kaiser Permanente Northern California members who underwent their first colonoscopy during 2006-2016. Nested within this population, we identified 695 cases of CRC and 3475 CRC-free controls (matched 5:1 to cases for age, sex and year of colonoscopy). Two expert pathologists reviewed the tissue slides of all SPs identified on the first colonoscopy and reclassified them to sessile serrated lesions (SSLs), hyperplastic polyps (HPs) and traditional serrated adenomas. SPs with borderline characteristics of SSLs but insufficient to make a definitive diagnosis were categorised as unspecified SPs. The association with development of CRC was assessed using multivariable logistic regression.

RESULTS

Compared with individuals with no polyp, the adjusted ORs (aORs) for SSL alone or with synchronous adenoma were 2.9 (95% CI: 1.8 to 4.8) and 4.4 (95% CI: 2.7 to 7.2), respectively. The aORs for SSL with dysplasia, large proximal SSL,and small proximal SSL were 10.3 (95% CI: 2.1 to 50.3), 12.8 (95% CI: 3.5 to 46.9) and 1.9 (95% CI: 0.8 to 4.7), respectively. Proximal unspecified SP also conferred an increased risk (aOR: 5.8, 95% CI: 2.2 to 15.2). Women with SSL were associated with higher risk (aOR: 4.4; 95% CI: 2.3 to 8.2) than men (aOR: 1.7; 95% CI: 0.8 to 3.8).

CONCLUSION

Increased risk of CRC was observed in individuals with SSLs, particularly large proximal ones or with dysplasia, supporting close endoscopic surveillance. Proximal unspecified SPs were also associated with increased risk of CRC and should be managed as SSLs.

AGA Clinical Practice Update on Strategies to Improve Quality of Screening and Surveillance Colonoscopy: Expert Review

The purpose of this American Gastroenterological Association Institute Clinical Practice Update was to review the available evidence and provide best practice advice regarding strategies to improve the quality of screening and surveillance colonoscopy. This review is framed around 15 best practice advice statements regarding colonoscopy quality that were agreed upon by the authors, based on a review of the available evidence and published guidelines. This is not a formal systematic review and thus no formal rating of the quality of evidence or strength of recommendation has been carried out.

Colorectal Cancer Screening and Postpolypectomy Surveillance

CASE SUMMARY

A healthy 52-year-old woman without any family history presents for a health maintenance appointment and opts for a fecal immunochemical test for colorectal cancer screening after reviewing her options. After a positive result, she is referred for colonoscopy. She is found to have 3 small (<10 mm) polyps that are completely resected via snare polypectomy and return as tubular adenomas on histologic examination. It is recommended that she return for repeat colonoscopy in 3 years, at which point she has a normal examination with excellent preparation by an experienced endoscopist and is given the option to return to her average-risk screening interval.

Risk of metachronous neoplastic lesions during post-polypectomy surveillance in individuals with advanced colorectal neoplasia at initial screening colonoscopy

BACKGROUND AND AIM

The evidence of associations between some types of advanced colorectal neoplasia (ACN) at baseline and the risk of metachronous neoplasia is inconsistent. This study aimed to elucidate the incidence of metachronous neoplasia during post-polypectomy surveillance in individuals with ACN at baseline and examine the risk factors for its high incidence.

METHODS

Data from individuals who underwent endoscopic resection for ACN and received surveillance colonoscopy were analyzed. Data from individuals with no neoplastic lesions at baseline were used as reference. The incidence of metachronous ACN and clinically significant neoplasia (ACN and nonadvanced adenomas sized ≥ 5 mm) were evaluated. Risk factors for the higher incidence of these lesions were examined in individuals with ACN at baseline.

RESULTS

During the median follow-up period of 61.8 months, metachronous ACN and nonadvanced adenomas sized ≥ 5 mm were detected in 9.6% and 32.4% of individuals with ACN at baseline (n = 136), respectively. The cumulative incidence of metachronous ACN and clinically significant neoplasia in individuals with ACN at baseline (3-year incidence: 5.5% and 16.9%, respectively) was higher than that in individuals with no neoplastic lesions at baseline (P < 0.01 for both). The presence of advanced histology at baseline, ≥ 5 neoplastic lesions at baseline, and family history of colorectal cancer were identified as risk factors for the higher incidence of clinically significant neoplasia.

CONCLUSIONS

The relatively high incidence of metachronous neoplasia in individuals with ACN at baseline was confirmed; careful surveillance is required for these individuals, particularly in those with the risk factors.

Incidental Polyp on Colectomy Specimen is Linked with Higher Odds of Polyp on Interval Colonoscopy

BACKGROUND

Incidentally found polyps on surgical pathology after colectomy is an underreported phenomenon, and management guidelines are lacking. Elucidation of the significance of incidental polyps is needed to determine if post-operative endoscopic surveillance modification is warranted. We sought to determine the relationship between incidental polyp on colectomy specimen and findings on post-operative colonoscopy.

MATERIALS AND METHODS

A multi-institutional retrospective review was performed on patients that underwent colorectal resection from 2018-2019. Surgical pathology was reviewed for polyps and assigned as expected or incidental based on pre-operative colonoscopy. If performed, post-operative colonoscopy was reviewed for new lesion identification. The odds of detecting new lesion on post-operative colonoscopy was compared between cases with incidental polyp on surgical specimen and patients without incidental findings.

RESULTS

In 243 colorectal resections, incidental polyps were identified in 55 cases(22.6%). Post-operative colonoscopy was completed in 65 cases(26.7%) with new polyp detected in 24 cases(9.88%). Of those, 10 had an incidental polyp previously identified on surgical specimen while 14 did not. The presence of incidental surgical specimen polyp was associated with a greater than two-fold higher odds of detecting new polyp on post-operative colonoscopy(odds-ratio 2.76, 95% confidence interval 1.15-6.63;P = 0.023).

CONCLUSION

This analysis revealed a high frequency of incidental polyps on surgical specimens with an increased rate of newly found lesions on post-operative colonoscopy. Incidental polyps may be a risk factor for other missed lesions still within the patient. Therefore, providers should consider surveillance interval modification on an individual basis in the setting of incidental surgical specimen polyps.

Incidence of Colorectal Adenomas After Bariatric Surgery: Pre-operative Super Morbid Obesity Is Independently Associated with Increased Risk

PURPOSE

The impact of pre-bariatric surgery BMI on the incidence of colorectal adenomas in the post-operative period is unknown. Here we aim to evaluate the incidence of colorectal adenomas after bariatric surgery and to assess super morbid obesity (SMO) as a risk factor for post-operative colorectal adenomas.

MATERIALS AND METHODS

An inception cohort of 1639 patients that underwent bariatric surgery between 2011 and 2019 in a referral center was retrospectively analyzed. SMO was defined as BMI > 50.0 kg/m². Cox regression analysis was performed to assess the influence of pre-operative BMI on the primary outcome.

RESULTS

A total 381 patients (23.2% of the cohort) underwent colonoscopy and included in the analysis. Mean age was 51.1 years (± 10.6) with mean BMI of 42.2 kg/m² (± 6.2), and 49 patients (12.9%) had SMO. Median time to colonoscopy was 3.5 years. One hundred nine patients (28.6%) had colorectal polyps, and 38/109 (34.8%) had advanced adenoma. Two patients had colorectal cancer (CRC). Pre-procedural SMO was associated with diagnosis of colorectal polyp (HR 2.4, 95% CI 1.5-3.9, p < 0.001) and advanced adenomas (HR 4.2, 95% CI 2.0-8.9, p < 0.001) upon adjustment to previously reported risk factors of CRC.

CONCLUSION

Pre-procedural SMO is associated with increased risk of colorectal adenomas after bariatric surgery compared to obese and morbidly obese individuals. Pre-operative BMI should be incorporated into post-operative screening plan in this population.

Colorectal Cancer Screening with Computed Tomography Colonography: Single Region Experience in Kazakhstan

Background/Aims

The aim of our study was to determine the efficacy of computed tomography colonography (CTC) in screening for colorectal cancer (CRC).

Methods

A total of 612 females and 588 males aged 45 to 75 years were enrolled in CTC screening. CTC was performed following standard bowel preparation and colonic insufflation with carbon dioxide. The main outcomes were the detection rate of CRC and advanced adenoma (AA), prevalence of colorectal lesions in relation to socio-demographic and health factors, and overall diagnostic performance of CTC.

Results

Overall, 56.5% of the 1,200 invited subjects underwent CTC screening. The sensitivity for CRC and AA was 0.89 and 0.97, respectively, while the specificity was 0.71 and 0.99, respectively. The prevalence of CRC and AA was 3.0% (18/593) and 7.1% (42/593), respectively, with the highest CRC prevalence in the 66-75 age group (≥12 times; odds ratio [OR], 12.11; 95% confidence interval [CI], 4.45-32.92). CRC and AA prevalence were inversely correlated with Asian descent, physical activity, and negative fecal immunochemical test results (OR=0.43; 95% CI, 0.22-0.83; OR=0.16; 95% CI, 0.04-0.68; OR=0.5; 95% CI, 0.07-3.85, respectively).

Conclusions

Our study revealed high accuracy of CTC in diagnosing colonic neoplasms, good compliance with CTC screening, and high detection rate of CRC.

Update in Outpatient General Internal Medicine: Practice-Changing Evidence Published in 2020

In a time of rapidly shifting evidence-based medicine, it is challenging to stay informed of research that modifies clinical practice. To enhance knowledge of practice-changing literature, a group of 7 internists reviewed titles and abstracts in 7 internal medicine journals with the highest impact factors and relevance to outpatient general internal medicine. Coronavirus disease-19 research was purposely excluded to highlight practice changes beyond the pandemic. New England Journal of Medicine (NEJM), The Lancet, Annals of Internal Medicine, Journal of the American Medical Association (JAMA), JAMA Internal Medicine, British Medical Journal (BMJ), and Public Library of Science (PLoS) Medicine were reviewed. The following collections of article synopses and databases were also reviewed: American College of Physicians Journal Club, NEJM Journal Watch, BMJ Evidence-Based Medicine, McMaster/DynaMed Evidence Alerts, and Cochrane Reviews. A modified Delphi method was used to gain consensus based on relevance to outpatient internal medicine, impact on practice, and strength of evidence. Clusters of articles pertaining to the same topic were considered together. In total, 7 practice-changing articles were included.

Simple Sugar and Sugar-Sweetened Beverage Intake During Adolescence and Risk of Colorectal Cancer Precursors

BACKGROUND & AIMS

Recent increasing trends in early-onset colorectal cancer (CRC) strongly supports that early-life diet is involved in CRC development. However, data are lacking on the relationship with high sugar intake during early life.

METHODS

We prospectively investigated the association of adolescent simple sugar (fructose, glucose, added sugar, total sugar) and sugar-sweetened beverage (SSB) intake with CRC precursor risk in 33,106 participants of the Nurses' Health Study II who provided adolescent dietary information in 1998 and subsequently underwent lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for clustered data.

RESULTS

During follow-up, 2909 conventional adenomas (758 high-risk) and 2355 serrated lesions were identified (mean age at diagnoses, 52.2 ± 4.3 years). High sugar and SSB intake during adolescence was positively associated with risk of adenoma, but not serrated lesions. Per each increment of 5% of calories from total fructose intake, multivariable ORs were 1.17 (95% CI, 1.05-1.31) for total and 1.30 (95% CI, 1.06-1.60) for high-risk adenoma. By subsite, ORs were 1.12 (95% CI, 0.96-1.30) for proximal, 1.24 (95% CI, 1.05-1.47) for distal, and 1.43 (95% CI, 1.10-1.86) for rectal adenoma. Per 1 serving/day increment in SSB intake, ORs were 1.11 (95% CI, 1.02-1.20) for total and 1.30 (95% CI, 1.08-1.55) for rectal adenoma. Contrary to adolescent intake, sugar and SSB intake during adulthood was not associated with adenoma risk.

CONCLUSIONS

High intake of simple sugars and SSBs during adolescence was associated with increased risk of conventional adenoma, especially rectal adenoma.

Age, male sex, smoking and metabolic syndrome as risk factors of advanced colorectal neoplasia for fecal immunochemical test negative patients

BACKGROUND

Fecal immunochemical test (FIT) is worldwide strategy for colorectal cancer screening. The subjects with negative FIT still have the risk of an advanced colorectal neoplasia (AN), including adenoma with villous histology, high grade dysplasia or larger than 1 cm in size, or adenocarcinoma. The study determined the risk factors associated with AN in FIT-negative subjects.

METHODS

The study included asymptomatic subjects who received health checkup colonoscopy and have provided FIT study within 6 months prior to colonoscopy. The risk factors to have AN in cases with negative FIT were analyzed. The numbers of colonoscopies needed to detect one AN were calculated for the subjects with different risk factors.

RESULTS

There were 1411 cases, 85 with positive FIT and 1326 with negative FIT within 6 months before colonoscopy. In FIT positive and FIT negative cases, 45.9% and 34.6% were found to have colorectal adenoma, while 20.2% and 4.6% had AN, respectively. The univariate and multivariate logistic regression analyses showed that age more than 50 years old, male sex, smoking history and metabolic syndrome were the significant risk factors to have AN in the FIT negative cases. For cases with negative FIT to have these risk factors, the number of colonoscopies needed to detect one AN was 3.7, lower than 4.5 of the cases with positive FIT.

CONCLUSION

For the cases with negative FIT, colonoscopy screening should be considered for those male patients over 50 years old, with a history of smoking and metabolic syndrome to detect AN.

Post-polypectomy surveillance colonoscopy: Comparison of the updated guidelines

Background

Recently, three updated guidelines for post‐polypectomy colonoscopy surveillance (PPCS) have been published. These guidelines are based on a comprehensive summary of the literature, while some recommendations are similar, different surveillance intervals are recommended after detection of specific types of polyps.

Aim

In this review, we aimed to compare and contrast these recommendations.

Methods

The updated guidelines for PPCS were reviewed and the recommendations were compared.

Results

For patients with 1–4 adenomas <10 mm with low‐grade dysplasia, irrespective of villous components, or 1–4 serrated polyps <10 mm without dysplasia, the European Society of Gastrointestinal Endoscopy (ESGE) and British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE) (BSG/ACPGBI/PHE) guidelines do not recommend colonoscopic surveillance and instead recommend that the participate in routine CRC screening program (typically based on the fecal immunochemical test), while the USMSTF recommends surveillance colonoscopies 7–10 years after diagnosis of 1–2 tubular adenomas <10 mm and 3–5 years for 3–4 tubular adenomas of the same size. The USMSTF define adenomas with tubulovillous or villous histology as high‐risk adenomas; thus, surveillance colonoscopy is recommended after 3 years. However, the ESGE and BSG do not consider such histology as a criterion for repeating colonoscopy at this short interval. For patients with 1–2 sessile serrated polyps (SSPs) <10 mm and those with 3–4 SSPs <10 mm, the USMSTF recommends surveillance colonosocopy after 5–10 and 3–5 years, respectively.

Clinical validation of the SIMPLE classification for optical diagnosis of colorectal polyps

Background and study aims  A novel endoscopic optical diagnosis classification system (SIMPLE) has recently been developed. This study aimed to evaluate the SIMPLE classification in a clinical cohort. Patients and methods  All diminutive and small colorectal polyps found in a cohort of individuals undergoing screening, diagnostic, or surveillance colonoscopies underwent optical diagnosis using image-enhanced endoscopy (IEE) and the SIMPLE classification. The primary outcome was the agreement of surveillance intervals determined by optical diagnosis compared with pathology-based results for diminutive polyps. Secondary outcomes included the negative predictive value (NPV) for rectosigmoid adenomas, the percentage of pathology exams avoided, and the percentage of immediate surveillance interval recommendations. Analysis of optical diagnosis for polyps ≤ 10 mm was also performed. Results  399 patients (median age 62.6 years; 55.6 % female) were enrolled. For patients with at least one polyp ≤ 5 mm undergoing optical diagnosis, agreement with pathology-based surveillance intervals was 93.5 % (95 % confidence interval [CI] 91.4-95.6). The NPV for rectosigmoid adenomas was 86.7 % (95 %CI 77.5-93.2). When using optical diagnosis, pathology analysis could be avoided in 61.5 % (95 %CI 56.9-66.2) of diminutive polyps, and post-colonoscopy surveillance intervals could be given immediately to 70.9 % (95 %CI 66.5-75.4) of patients. For patients with at least one ≤ 10 mm polyp, agreement with pathology-based surveillance intervals was 92.7 % (95 %CI 89.7-95.1). NPV for rectosigmoid adenomas ≤ 10 mm was 85.1 % (95 %CI CI 76.3-91.6). Conclusions  IEE with the SIMPLE classification achieved the quality benchmark for the resect and discard strategy; however, the NPV for rectosigmoid polyps requires improvement.

Risk of Colorectal Cancer and Cancer Related Mortality After Detection of Low-risk or High-risk Adenomas, Compared With No Adenoma, at Index Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The risk of metachronous colorectal cancer (CRC) among patients with no adenomas, low-risk adenomas (LRAs), or high-risk adenomas (HRAs), detected at index colonoscopy, is unclear. We performed a systematic review and meta-analysis to compare incidence rates of metachronous CRC and CRC-related mortality after a baseline colonoscopy for each group.

METHODS

We searched the PubMed, Embase, Google Scholar, and Cochrane databases for studies that reported the incidence of CRC and adenoma characteristics after colonoscopy. The primary outcome was odds of metachronous CRC and CRC-related mortality per 10,000 person-years of follow-up after baseline colonoscopy for all the groups.

RESULTS

Our final analysis included 12 studies with 510,019 patients (mean age, 59.2 ± 2.6 years; 55% male; mean duration of follow up, 8.5 ± 3.3 years). The incidence of CRC per 10,000 person-years was marginally higher for patients with LRAs compared to those with no adenomas (4.5 vs 3.4; odds ratio [OR], 1.26; 95% CI, 1.06-1.51; I²=0), but significantly higher for patients with HRAs compared to those with no adenoma ( 13.8 vs 3.4; odds ratio [OR], 2.92; 95% CI, 2.31-3.69; I²=0 ) and patients with HRAs compared to LRAs (13.81 vs 4.5; OR, 2.35; 95% CI, 1.72-3.20; I²=55%). However, the CRC-related mortality per 10,000 person-years did not differ significantly for patients with LRAs compared to no adenomas (OR, 1.15; 95% CI, 0.76-1.74; I²=0) but was significantly higher in persons with HRAs compared with LRAs (OR, 2.48; 95% CI, 1.30-4.75; I²=38%) and no adenomas (OR, 2.69; 95% CI, 1.87-3.87; I²=0).

CONCLUSIONS

The results of this systematic review and meta-analysis demonstrate that the risk of metachronous CRC and mortality is significantly higher for patients with HRAs, but this risk is very low in patients with LRAs, comparable to patients with no adenomas. Follow-up of patients with LRAs detected at index colonoscopy should be the same as for persons with no adenomas.

Field carcinogenesis for risk stratification of colorectal cancer

Colorectal cancer (CRC) is characterized by genetic-environmental interplay leading to diffuse changes in the entire colonic mucosa (field carcinogenesis or field of injury) and to a pro-neoplastic genetic/epigenetic/physiological milieu. The clinical consequences are increased risk of synchronous and metachronous neoplasia. Factors such as genetics, race, ethnicity, age, and socioeconomic status are thought to influence neoplasia development. Here, we explore the potential improvement to CRC screening through exploiting field carcinogenesis, with particular focus on racial disparities and chemoprevention strategies. Also, we discuss future directions for field carcinogenesis/risk stratification using molecular and novel biophotonic techniques for personalized CRC screening.

CircRNA circ_0124554 blocked the ubiquitination of AKT promoting the skip lymphovascular invasion on hepatic metastasis in colorectal cancer

Colorectal cancer (CRC) is the fourth most common cancer in men and the third most common cancer in women worldwide. The incidence and mortality of CRC was increasing rapidly in China. Lymph node-negative colorectal cancer patients with synchronous liver metastasis (LNLM1) was defined as "skip" lymph vascular invasion on hepatic metastasis, who presenting poor prognosis. We aiming to investigate the potential mechanism for the "skip" lymph vascular invasion on hepatic metastasis in colorectal cancer. The microarray was applied for screening the transcription landscape of circRNA in lymph node negative CRC patients with synchronous liver metastasis (LNLM1) or without liver metastasis (LNLM0). We identified the aberrant increased circRNA circ_0124554 (also entitled as circ-LNLM) in tumor tissues of LNLM1 patients comparing with either the tumor tissues of LNLM0 or adjacent tissues of LNLM1. Circ-LNLM1 expression was highly correlated with liver metastasis and vascular invasion. Ectopic expression of cytoplasmic located circ-LNLM could promote invasion of CRC cells and induced the liver metastasis in animal models through the direct binding with AKT. The phosphorylation of AKT (T308/S473) was activated due to the blocked ubiquitination site of Lys in 0-52aa peptide of circ-LNLM. Endogenous plasma expression of circ-LNLM induced poor prognosis of LNLM1 and could distinguish LNLM1 patients from LNLM0. In conclusion, the circ-LNLM blocked the ubiquitination of AKT could promote the early metastasis especially for the lymph node-negative colorectal cancer patients with synchronous liver metastasis. The circ-LNLM might be prognosis and diagnosis biomarker for LNLM1 patients.

Optical diagnosis of colorectal polyps: a randomized controlled trial comparing endoscopic image-enhancing modalities

BACKGROUND AND AIMS

Optical polyp diagnosis using image-enhanced endoscopy (IEE) allows for real-time histology prediction of colorectal polyps. The aim of this study was to evaluate a recently introduced IEE modality (Optivista [OV]; Pentax Medical, Tokyo, Japan) in a randomized controlled trial.

METHODS

In a prospective cohort of subjects (ages 45-80 years) undergoing elective screening, surveillance, or diagnostic colonoscopy, all colorectal polyps between 1 and 5 mm underwent IEE assessment. Study subjects were randomized before their colonoscopy procedure to undergo optical polyp diagnosis using either OV IEE or iScan (IS) IEE. A validated IEE scale (NBI International Colorectal Endoscopic classification) was used for optical polyp diagnosis. The primary outcome was the agreement of surveillance intervals determined when using OV IEE compared with IS IEE in reference with pathology-based surveillance intervals. Secondary outcomes were the percentage of surveillance intervals that could be given on the same day as the procedure, percentage of pathology tests avoided, diagnostic performance, and negative predictive value (NPV) of optical diagnosis for rectosigmoid adenomas.

RESULTS

Four hundred ten patients were enrolled in the trial. The polyp detection rate was 58.6%, and the adenoma detection rate was 38.8%. The proportion of correct surveillance interval assignment when using OV or IS IEE was 96.5% versus 96.0% (P = .75). A total of 65.1% of patients could be given same-day surveillance intervals when using OV IEE versus 73.1% for IS IEE (P = .07). The NPV for rectosigmoid adenomas (including sessile serrated adenomas) was 97.5% when using OV IEE and 88.2% when using IS IEE. Using high-confidence optical diagnosis instead of pathology would have resulted in a 44.3% elimination of required pathology examinations for OV IEE versus 52.8% for IS IEE (P = .34).

CONCLUSIONS

Optical diagnosis using OV and IS IEE both surpassed the 90% benchmark of surveillance interval assignment, and no significant difference with regard to correct surveillance interval assignment was found. OV IEE surpassed the ≥90% NPV for rectosigmoid adenomas, whereas IS IEE did not. (Clinical trial registration number: NCT03515343.).