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

Clinicopathological and molecular landscape in colorectal cancer associated with colorectal polyps and inflammatory bowel disease

Although inflammatory bowel disease (IBD) and colorectal polyps are considered as significant risk factors of colorectal cancer (CRC), the molecular mechanism associated with colorectal carcinogenesis is still explored. Unlike sporadic CRC, local persistent inflammation in IBD induces genetic and epigenetic alterations, leading to tumor development. Moreover, cumulative data indicate that colorectal polyps display a significant malignant potential. In this context, our study aimed to investigate the clinicopathological features of CRC associated with IBD and/or colorectal neoplastic polyps in a retrospective group of CRC cases. The clinical data and histopathological features of CRC cases have been collected from our files. Immunohistochemical examination of mismatch repair (MMR) proteins has been performed in a selected case. The study group comprised 40 patients, 72.5% men and 27.5% women, with a median age of 64.73±9.09 years. Out of the cases with double association, 62.5% of CRC cases displayed colorectal polyps, while 32.5% of patients were diagnosed with both CRC and IBD, which encompassed both ulcerative colitis (UC) and Crohn's disease (CD). Two patients included in our study group exhibited a triple association of IBD, colorectal polyps, and CRC, one of them showing defective MMR (dMMR) phenotype. Although our results provide significant data on the relationship between IBD, colorectal polyps, and colorectal carcinogenesis, future cohort studies are needed to improve our understanding on the complex mechanism of colorectal carcinogenesis, ultimately guiding improved prevention, diagnosis, and treatment strategies for these patients.

Risk factors for metachronous colorectal cancer or advanced lesions after endoscopic resection of serrated polyps: a systematic review and meta-analysis

BACKGROUND AND AIMS

Serrated polyps (SPs) are precursors to 15% to 20% of colorectal cancers (CRCs). However, there are uncertainties regarding which SPs require surveillance and at what intervals, with recommendations adapted from those for adenomas in the absence of solid evidence. Our aim was to assess which SP risk characteristics relate to a higher risk of metachronous CRC or advanced polyps.

METHODS

We systematically searched PubMed, Embase, and Cochrane for cohort studies, case-control studies, and clinical trials from inception to December 31, 2023, of CRC or advanced polyps (advanced adenoma [AA] or advanced SP) incidence at surveillance stratified by baseline SP size, dysplasia, location, and multiplicity. We defined advanced SPs as those ≥10 mm or with dysplasia. CRC and advanced polyp incidence per 1000 person-years were estimated. We performed a meta-analysis by calculating pooled relative risks (RRs) using a random-effects model.

RESULTS

A total of 5903 studies were reviewed, and 14 were included with 493,949 patients (mean age, 59.5 years; 55% men). The mean follow-up was 4.9 years. CRC incidence per 1000 person-years was 2.09 (95% confidence interval [CI], 1.29-2.90) for advanced SPs, 1.52 (95% CI, 0.78-2.25) for SPs of ≥10 mm, 5.86 (95% CI, 2.16-9.56) for SPs with dysplasia, 1.18 (95% CI, 0.77-1.60) for proximal SPs, 0.52 (95% CI, 0.08-1.12) for ≥3 SPs, 0.50 (95% CI, 0.35-0.66) for nonadvanced SPs, and 0.44 (95% CI, 0.41-0.46) for normal colonoscopy findings. Metachronous CRC risk was higher in advanced SPs versus nonadvanced SPs (RR, 1.84; 95% CI, 1.11-3.04) and versus normal colonoscopy findings (RR, 2.92; 95% CI, 2.26-3.77), in SPs of ≥10 mm versus <10 mm (RR, 2.61; 95% CI, 1.43-4.77) and versus normal colonoscopy findings (RR: 3.52; 95% CI, 2.17-5.69); and in SPs with dysplasia versus normal colonoscopy findings (RR: 2.71; 95% CI, 2.00-3.67). No increase in CRC or advanced polyp risk was found in patients with proximal versus distal SPs, nor in ≥3 SPs versus 1 or 2 SPs.

CONCLUSIONS

CRC risk is significantly higher in patients with baseline advanced SPs after 4.9 years of follow-up, with risk magnitudes similar to those described for AA, supporting the current recommendation for 3-year surveillance in patients with advanced SPs.

Characteristics of a cost-effective blood test for colorectal cancer screening

BACKGROUND

Blood-based biomarker tests can potentially change the landscape of colorectal cancer (CRC) screening. We characterize the conditions under which blood test screening would be as effective and cost-effective as annual fecal immunochemical testing or decennial colonoscopy.

METHODS

We used the 3 Cancer Information and Surveillance Modeling Network-Colon models to compare scenarios of no screening, annual fecal immunochemical testing, decennial colonoscopy, and a blood test meeting Centers for Medicare & Medicaid (CMS) coverage criteria (74% CRC sensitivity and 90% specificity). We varied the sensitivity to detect CRC (74%-92%), advanced adenomas (10%-50%), screening interval (1-3 years), and test cost ($25-$500). Primary outcomes included quality-adjusted life-years (QALY) gained from screening and costs for a US average-risk cohort of individuals aged 45 years.

RESULTS

Annual fecal immunochemical testing yielded 125-163 QALY gained per 1000 at a cost of $3811-$5384 per person, whereas colonoscopy yielded 132-177 QALY gained at a cost of $5375-$7031 per person. A blood test with 92% CRC sensitivity and 50% advanced adenoma sensitivity yielded 117-162 QALY gained if used every 3 years and 133-173 QALY gained if used every year but would not be cost-effective if priced above $125 per test. If used every 3 years, a $500 blood test only meeting CMS coverage criteria yielded 83-116 QALY gained at a cost of $8559-$9413 per person.

CONCLUSION

Blood tests that only meet CMS coverage requirements should not be recommended to patients who would otherwise undergo screening by colonoscopy or fecal immunochemical testing because of lower benefit. Blood tests need higher advanced adenoma sensitivity (above 40%) and lower costs (below $125) to be cost-effective.

Evaluation of long-term benefits and cost-effectiveness of nation-wide colorectal cancer screening strategies in China in 2020-2060: a modelling analysis

Background

Evidence on the long-term benefits and cost-effectiveness of colorectal cancer (CRC) screening strategies in China remains limited. This modelling study aims to address this issue for various CRC screening strategies in China between 2020 and 2060.

Methods

Using a previously developed microsimulation model (MIMIC-CRC) with Chinese epidemiological data, we evaluated four CRC screening strategies targeting population aged 45-74 years: no screening, colonoscopy every 10 years, biennial faecal immunochemical testing (FIT), and a roll-out FIT screening strategy. Screening coverage (invitation) rates from 5% to 100% were analysed. Single-cohort analysis of 100,000 individuals was conducted to estimate the relative cost-effectiveness of each strategy. A multiple-cohort analysis of 100,000 people aged 40+ over 2020-2060 was conducted to project nation-wide long-term benefits and cost-effectiveness.

Findings

In single-cohort analysis, all strategies yielded reductions in CRC incidence and mortality compared to no screening, with colonoscopy outperforming FIT-based strategies at the same invitation rates. In multiple-cohort analysis, among people over 40 years of age in China over 2020-2060, compared to no screening, at invitation rate of 5%, screening by colonoscopy, biennial FIT and roll-out FIT-based approach were estimated to avert 1.2, 0.4, and 0.3 million incident CRCs and 0.2, 0.1, and 0.1 million CRC-related deaths, respectively, compared to no screening (25.4 million incident CRCs and 4.4 million CRC-related deaths), and this preventive effect enlarged as the screening coverage rate increased. At full coverage, colonoscopy achieved the largest reductions (38.2% lower incidence and 43.2% lower mortality) but required the most resources. Biennial FIT and roll-out FIT-based approach screening was slightly less effective but had significant reduced colonoscopy needs (reduction of 83.8% and 85.2%, respectively) and overall cost (reduction of 23.4% and 37.8%, respectively) compared to colonoscopy screening.

Interpretation

Nation-wide implementation of screening would be effective in reducing the burden of CRC in China. Biennial FIT and roll-out FIT-based screening strategies could prevent incident CRC cases and CRC-related deaths with considerably fewer resources than colonoscopy screening. Efforts should be made to increase the screening coverage in China.

Funding

Chinese Academy of Medical Science Innovation Fund for Medical Science (2022-I2M-1-0031); National Natural Science Foundation of China (82173606; 82273726); Beijing Nova Program of Science and Technology (20230484397).

Risk of colorectal neoplasia after removal of conventional adenomas and serrated polyps: a comprehensive evaluation of risk factors and surveillance use

BACKGROUND

Surveillance colonoscopy after polyp removal is recommended to prevent subsequent colorectal cancer (CRC). It is known that advanced adenomas have a substantially higher risk than non-advanced ones, but optimal intervals for surveillance remain unclear.

DESIGN

We prospectively followed 156 699 participants who had undergone a colonoscopy from 2007 to 2017 in a large integrated healthcare system. Using multivariable Cox proportional hazards regression we estimated the subsequent risk of CRC and high-risk polyps, respectively, according to index colonoscopy polyps, colonoscopy quality measures, patient characteristics and the use of surveillance colonoscopy.

RESULTS

After a median follow-up of 5.3 years, we documented 309 CRC and 3053 high-risk polyp cases. Compared with participants with no polyps at index colonoscopy, those with high-risk adenomas and high-risk serrated polyps had a consistently higher risk of CRC during follow-up, with the highest risk observed at 3 years after polypectomy (multivariable HR 5.44 (95% CI 3.56 to 8.29) and 8.35 (95% CI 4.20 to 16.59), respectively). Recurrence of high-risk polyps showed a similar risk distribution. The use of surveillance colonoscopy was associated with lower risk of CRC, with an HR of 0.61 (95% CI 0.39 to 0.98) among patients with high-risk polyps and 0.57 (95% CI 0.35 to 0.92) among low-risk polyps. Among 1548 patients who had high-risk polyps at both index and surveillance colonoscopies, 65% had their index polyps in the proximal colon and 30% had index and interval polyps in the same segments.

CONCLUSION

Patients with high-risk polyp findings were at higher risk of subsequent CRC and high-risk polyps and may benefit from early surveillance within 3 years. The subsite distribution of the index and recurrent high-risk polyps suggests the contribution of incomplete resection and missed lesions to the development of interval neoplasia.

Metachronous Colorectal Neoplasia in Young Adults With Advanced Neoplasia Undergoing Colonoscopy: A Comparison of Risk by Age <45 Years Versus 45 to 49 Years

BACKGROUND

The risk of metachronous advanced colorectal neoplasia (mACRN) in young adults with advanced lesions at baseline colonoscopy is not well defined.

AIMS

To examine the risk for (mACRN) in adults <50 years old who had advanced neoplasia (AN) at baseline colonoscopy and determine factors associated with mACRN in these patients.

METHOD

Patients 18 to 49 years of age with ≥1 AN [tubular adenoma (TA) ≥10 mm or with villous features or high-grade dysplasia (HGD), sessile serrated lesion (SSL) ≥10 mm or with dysplasia, traditional serrated adenoma (TSA)] on baseline colonoscopy between 2011 and 2021 who had surveillance colonoscopy >6 months after their baseline examination were included. Outcomes were assessed based on age at baseline colonoscopy, <45 years versus 45 to 49 years, and by follow-up colonoscopy findings: (1) normal, (2) nonadvanced neoplasia (NAN), and (3) AN.

RESULTS

Three hundred sixty-six patients with AN underwent ≥1 surveillance colonoscopy: 310 (84.7%) <45 years versus 56 (15.3%) 45 to 49 years. The mean follow-up time was longer for the <45-year-olds versus the 45 to 49-year-olds (43±26.4 vs. 28.4±12.8 mo respectively, P<0.001). The absolute risk of mACRN was 13.5% in the <45 age group versus 16.1% in the 45 to 49 age group, P=0.28. The 3-year cumulative incidence rates of mACRN were comparable for patients <45 and 45 to 49 years old: 10% (95% CI: 10% to 42%) versus 20% (95% CI: 7% to 15%), P=0.065. BMI was the only risk factor associated with mACRN OR 1.045 [95% CI (1.001 to 1.09)].

CONCLUSIONS

In our cohort of patients <50 years old with AN at baseline, mACRN occurred at a similar rate to that reported by guidelines in 50 years and older, suggesting that current recommended post polypectomy surveillance is appropriate for this age group. BMI was independently associated with mACRN. Future studies should examine how weight management in patients with high BMI mitigates the recurrence of advanced neoplasia.

Impact of the serrated pathway on the simulated comparative effectiveness of colorectal cancer screening tests

BACKGROUND

Colorectal cancers (CRCs) arise from adenomas, which can produce fecal occult blood and can be detected endoscopically, or sessile serrated lesions (SSLs), which rarely bleed and may be more challenging to detect. Models informing CRC screening policy should reflect both pathways, accounting for uncertainty.

METHODS

Novel decision-analytic model of the adenoma and serrated pathways for CRC (ANSER) to compare current and emerging screening strategies, accounting for differential test sensitivities for adenomas and SSLs, and uncertainty. Strategies included colonoscopy every 10 years, stool-DNA/FIT (sDNA-FIT) every 1-3 years, or fecal immunochemical testing (FIT) every year from age 45 to 75 years. Outcomes included CRC cases and deaths, cost-effectiveness (cost/quality-adjusted life-year [QALY] gained), and burden-benefit (colonoscopies/life-year gained), with 95% uncertainty intervals (UIs).

RESULTS

ANSER predicted 62.5 (95% UI = 58.8-66.3) lifetime CRC cases and 24.1 (95% UI = 22.5-25.7) CRC deaths/1000 45-year-olds without screening, and 78%-87% CRC mortality reductions with screening. The tests' outcome distributions overlapped for QALYs gained but separated for required colonoscopies and costs. All strategies cost less than $100 000/QALY gained vs no screening. Colonoscopy was the most effective and cost-effective, costing $9300/life-year gained (95% UI = $500-$21 900) vs FIT. sDNA-FIT cost more than $500 000/QALY gained vs FIT. As more CRCs arose from SSLs, colonoscopy remained preferred based on clinical benefit and cost-effectiveness, but cost-effectiveness improved for a next-generation sDNA-FIT.

CONCLUSION

When the serrated pathway is considered, modeling suggests that colonoscopy is cost-effective vs FIT. In contrast, modeling suggests that sDNA-FIT is not cost-effective vs FIT despite its greater sensitivity for SSLs, even if a substantial minority of CRCs arise from SSLs.

Dual Channel Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR) is the recommended technique for colon polypectomy for nonpedunculated lesions that are >20 mm in size not requiring excision. Dual-channel EMR (DC-EMR) uses an endoscope with two working channels to facilitate easier submucosal injection, snare resection, and clip closure of polypectomy defects. There is also promising early literature indicating that this endoscopic modality can reduce the overall learning curve present for single-channel colonoscopy EMR. This chapter will describe the steps and techniques required to perform DC-EMR, potential complications, recommended postprocedure surveillance, and future directions.

Hyperspectral imaging facilitating resect-and-discard strategy through artificial intelligence-assisted diagnosis of colorectal polyps: A pilot study

BACKGROUND AND AIMS

The resect-and-discard strategy for colorectal polyps based on accurate optical diagnosis remains challenges. Our aim was to investigate the feasibility of hyperspectral imaging (HSI) for identifying colorectal polyp properties and diagnosis of colorectal cancer in fresh tissues during colonoscopy.

METHODS

144,900 two dimensional images generated from 161 hyperspectral images of colorectal polyp tissues were prospectively obtained from patients undergoing colonoscopy. A residual neural network model was trained with transfer learning to automatically differentiate colorectal polyps, validated by histopathologic diagnosis. The diagnostic performances of the HSI-AI model and endoscopists were calculated respectively, and the auxiliary efficiency of the model was evaluated after a 2-week interval.

RESULTS

Quantitative HSI revealed histological differences in colorectal polyps. The HSI-AI model showed considerable efficacy in differentiating nonneoplastic polyps, non-advanced adenomas, and advanced neoplasia in vitro, with sensitivities of 96.0%, 94.0%, and 99.0% and specificities of 99.0%, 99.0%, and 96.5%, respectively. With the assistance of the model, the median negative predictive value of neoplastic polyps increased from 50.0% to 88.2% (p = 0.013) in novices.

CONCLUSION

This study demonstrated the feasibility of using HSI as a diagnostic tool to differentiate neoplastic colorectal polyps in vitro and the potential of AI-assisted diagnosis synchronized with colonoscopy. The tool may improve the diagnostic performance of novices and facilitate the application of resect-and-discard strategy to decrease the cost.

Provider Adherence to the 2020 US Multi-Society Task Force Guidelines for Surveillance After Colonoscopy With Polypectomy

Background and Aims

The 2020 United States Multi-Society Task Force on Colorectal Cancer guidelines for surveillance after colonoscopy with polypectomy introduced significant changes in surveillance intervals. We sought to identify rates of adherence to these new guidelines at an academic medical center.

Methods

Average-risk screening colonoscopies where 1 to 4 polyps <10 mm were removed between January 1, 2020, and June 30, 2021 were included. To determine predictors of nonadherence, a multivariable logistic regression analysis was conducted and included patient and procedure-related variables. Bayesian changepoint analysis was applied to identify timing of change in adherence. Multinomial logistic regression was used to identify predictors of variability within the guidelines.

Results

One thousand twenty-six procedures were analyzed. Adherence to the guidelines was 85%. In procedures with 1 to 2 polyps, increasing size (odds ratio [OR] 0.84 per mm; 95% confidence interval [CI]: 0.75-0.93) and a mixture of tubular adenomas (TA) and hyperplastic polyps (OR 0.35; 95% CI: 0.21-0.59) were associated with nonadherence. Among procedures with 1 to 2 TAs, age (OR 0.86 per 5-year increase; 95% CI: 0.75-0.99), increasing size (OR 0.86 per mm; 95% CI: 0.75-0.99) and polyp number (OR 0.54; 95% CI: 0.33-0.90) were associated with nonadherence. Changepoint analysis identified a potential changepoint on September 2, 2020 (95% credible interval April 2, 2020-February 22, 2020). Larger TAs were less likely to receive a 10-year recommendation (OR 0.61, 95% CI 0.5-0.75).

Conclusion

Adherence rates to the 2020 surveillance guidelines were high with a potential changepoint identified on 2/9/20. Deviation from guidelines was associated with patient and procedure related variables.

Gastrointestinal Cancer Precursor Conditions and Their Detection

Gastrointestinal cancers are a leading cause of cancer morbidity and mortality. Many gastrointestinal cancers develop from cancer precursor lesions, which are commonly found in individuals with hereditary cancer syndromes. Hereditary cancer syndromes have advanced our understanding of cancer development and progression and have facilitated the evaluation of cancer prevention and interception efforts. Common gastrointestinal hereditary cancer syndromes, including their organ-specific cancer risk and surveillance recommendations, are reviewed in this article. The management of common gastroesophageal, pancreatic, and colonic precursor lesions is also discussed, regardless of their genetic background. Further research is needed to advance chemoprevention and immunoprevention strategies.

Predicting Risk of Colorectal Cancer After Adenoma Removal in a Large Community-Based Setting

INTRODUCTION

Colonoscopy surveillance guidelines categorize individuals as high or low risk for future colorectal cancer (CRC) based primarily on their prior polyp characteristics, but this approach is imprecise, and consideration of other risk factors may improve postpolypectomy risk stratification.

METHODS

Among patients who underwent a baseline colonoscopy with removal of a conventional adenoma in 2004-2016, we compared the performance for postpolypectomy CRC risk prediction (through 2020) of a comprehensive model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and prior polyp findings (i.e., adenoma with advanced histology, polyp size ≥10 mm, and sessile serrated adenoma or traditional serrated adenoma) with a polyp model featuring only polyp findings. Models were developed using Cox regression. Performance was assessed using area under the receiver operating characteristic curve (AUC) and calibration by the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

Among 95,001 patients randomly divided 70:30 into model development (n = 66,500) and internal validation cohorts (n = 28,501), 495 CRC were subsequently diagnosed; 354 in the development cohort and 141 in the validation cohort. Models demonstrated adequate calibration, and the comprehensive model demonstrated superior predictive performance to the polyp model in the development cohort (AUC 0.71, 95% confidence interval [CI] 0.68-0.74 vs AUC 0.61, 95% CI 0.58-0.64, respectively) and validation cohort (AUC 0.70, 95% CI 0.65-0.75 vs AUC 0.62, 95% CI 0.57-0.67, respectively).

DISCUSSION

A comprehensive CRC risk prediction model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and polyp findings was more accurate at predicting postpolypectomy CRC diagnosis than a model based on polyp findings alone.

Measuring Size of Colorectal Polyps Using a Virtual Scale Endoscope or Visual Assessment: A Randomized Controlled Trial

INTRODUCTION

This study aimed to compare the accuracy of polyp size measurements using a virtual scale endoscope (VSE) with an integrated laser-based adaptive scale function and visual assessment (VA) during colonoscopies.

METHODS

We conducted a single-blinded, prospective randomized controlled trial. Eligible patients (aged 45-80 years) undergoing screening, surveillance, or diagnostic colonoscopies were randomly assigned (1:1) into 2 groups. In the intervention group, all detected polyps were measured for size using VSE; in the control group, all polyps were measured using VA. Size measurements were compared with a reference standard of digital caliper measurement immediately post polypectomy. The primary outcome was the relative accuracy of real-time VSE measurement compared with VA. Secondary outcomes included the mean differences and the correlations between VSE or VA sizes and the reference standard of measurement.

RESULTS

Overall, 230 patients were enrolled and randomized. The relative size measurement accuracy of VSE was 84% in 118 polyps, which was significantly higher than that of VA (105 polyps; 68.4%, P < 0.001). VSE resulted in a significantly higher percentage of size measurements within 25% of true size compared with VA (81.4% vs 41%, P < 0.001). VSE had a significantly lower percentage for >5-mm polyps incorrectly sized as 1-5 mm compared with VA (13.5% vs 57.1%; P < 0.001) and a significantly lower percentage for >3-mm polyps incorrectly sized as 1-3 mm compared with VA (11.3% vs 56.5%; P < 0.001).

DISCUSSION

VSE significantly improves the size measurement accuracy of colorectal polyps during colonoscopies compared with VA and results in fewer misclassifications at relevant decision-making size thresholds.

Serrated Polyps in Inflammatory Bowel Disease Indicate a Similar Risk of Metachronous Colorectal Neoplasia as in the General Population

BACKGROUND

The risk of metachronous advanced neoplasia after diagnosing serrated polyps in patients with IBD is poorly understood.

METHODS

A retrospective multicenter cohort study was conducted between 2010 and 2019 at three tertiary centers in Montreal, Canada. From pathology databases, we identified 1587 consecutive patients with serrated polyps (sessile serrated lesion, traditional serrated adenoma, or serrated epithelial change). We included patients aged 45-74 and excluded patients with polyposis, colorectal cancer, or no follow-up. The primary outcome was the risk of metachronous advanced neoplasia (advanced adenoma, advanced serrated lesion, or colorectal cancer) after index serrated polyp, comparing patients with and without IBD.

RESULTS

477 patients with serrated polyps were eligible (mean age 61 years): 37 with IBD, totaling 45 serrated polyps and 440 without IBD, totaling 586 serrated polyps. The median follow-up was 3.4 years. There was no difference in metachronous advanced neoplasia (HR 0.77, 95% CI 0.32-1.84), metachronous advanced adenoma (HR 0.54, 95% CI 0.11-2.67), and metachronous advanced serrated lesion (HR 0.76, 95% CI 0.26-2.18) risk. When comparing serrated polyps in mucosa involved or uninvolved with IBD, both groups had similar intervals from IBD to serrated polyp diagnosis (p > 0.05), maximal therapies (p > 0.05), mucosal inflammation, inflammatory markers, and fecal calprotectin (p > 0.05).

CONCLUSION

The risk of metachronous advanced neoplasia after serrated polyp detection was similar in patients with and without IBD. Serrated polyps in IBD occurred independently of inflammation. This helps inform surveillance intervals for patients with IBD diagnosed with serrated polyps.

Risk of advanced neoplasia after removal of colorectal adenomas with high-grade dysplasia

BACKGROUND

Many studies reported the presence of adenomas with high-grade dysplasia (HGD) at index colonoscopy increased the incidence of advanced neoplasia (AN) and colorectal cancer (CRC) following. However, the conclusion remains obscure due to lack of studies on the specific population of adenomas with HGD. This study aimed to assess the long-term risk of AN and CRC after removal of adenomas with HGD.

METHODS

A total of 814 patients who underwent adenomas with HGD removal between 2010 and 2019 were retrospectively analyzed. The outcomes were the incidences of AN and CRC during surveillance colonoscopy. Cox proportional hazards models were utilized to identify risk factors associated with AN and CRC.

RESULTS

During more than 2000 person-years of follow-up, we found that AN and CRC incidence densities were 44.3 and 4.4 per 1000 person-years, respectively. The 10-year cumulative incidence of AN and CRC were 39.1% and 5.5%, respectively. In the multivariate model, synchronous low-risk polyps (HR 1.80, 95% CI 1.10-2.93) and synchronous high-risk polyps (HR 3.99, 95% CI 2.37-6.72) were risk factors for AN, whereas participation in surveillance colonoscopy visits (HR 0.56, 95% CI 0.36-0.88 for 1 visit; HR 0.10, 95% CI 0.06-0.19 for ≥ 2 visits) were associated with decreased AN incidence. Additionally, elevated baseline carcinoembryonic antigen (CEA) level (HR 10.19, 95% CI 1.77-58.59) was a risk factor for CRC, while participation in ≥ 2 surveillance colonoscopy visits (HR 0.11, 95% CI 0.02-0.56) were associated with decreased CRC incidence. Interestingly, for 11 patients who developed CRC after removal of adenomas with HGD, immunohistochemistry revealed that 8 cases (73%) were deficient mismatch repair CRCs.

CONCLUSIONS

Patients who have undergone adenoma with HGD removal are at higher risk of developing AN and CRC, while surveillance colonoscopy can reduce the risk. Patients with synchronous polyps, or with elevated baseline CEA level are considered high-risk populations and require more frequent surveillance.

Autonomous Artificial Intelligence vs Artificial Intelligence-Assisted Human Optical Diagnosis of Colorectal Polyps: A Randomized Controlled Trial

BACKGROUND & AIMS

Artificial intelligence (AI)-based optical diagnosis systems (CADx) have been developed to allow pathology prediction of colorectal polyps during colonoscopies. However, CADx systems have not yet been validated for autonomous performance. Therefore, we conducted a trial comparing autonomous AI to AI-assisted human (AI-H) optical diagnosis.

METHODS

We performed a randomized noninferiority trial of patients undergoing elective colonoscopies at 1 academic institution. Patients were randomized into (1) autonomous AI-based CADx optical diagnosis of diminutive polyps without human input or (2) diagnosis by endoscopists who performed optical diagnosis of diminutive polyps after seeing the real-time CADx diagnosis. The primary outcome was accuracy in optical diagnosis in both arms using pathology as the gold standard. Secondary outcomes included agreement with pathology for surveillance intervals.

RESULTS

A total of 467 patients were randomized (238 patients/158 polyps in the autonomous AI group and 229 patients/179 polyps in the AI-H group). Accuracy for optical diagnosis was 77.2% (95% confidence interval [CI], 69.7-84.7) in the autonomous AI group and 72.1% (95% CI, 65.5-78.6) in the AI-H group (P = .86). For high-confidence diagnoses, accuracy for optical diagnosis was 77.2% (95% CI, 69.7-84.7) in the autonomous AI group and 75.5% (95% CI, 67.9-82.0) in the AI-H group. Autonomous AI had statistically significantly higher agreement with pathology-based surveillance intervals compared to AI-H (91.5% [95% CI, 86.9-96.1] vs 82.1% [95% CI, 76.5-87.7]; P = .016).

CONCLUSIONS

Autonomous AI-based optical diagnosis exhibits noninferior accuracy to endoscopist-based diagnosis. Both autonomous AI and AI-H exhibited relatively low accuracy for optical diagnosis; however, autonomous AI achieved higher agreement with pathology-based surveillance intervals. (ClinicalTrials.gov, Number NCT05236790).

Randomized Trial of Patient Outreach Approaches to De-implement Outdated Colonoscopy Surveillance Intervals

BACKGROUND AND AIMS

Guidelines now recommend patients with low-risk adenomas receive colonoscopy surveillance in 7-10 years and those with the previously recommended 5-year interval be re-evaluated. We tested 3 outreach approaches for transitioning patients to the 10-year interval recommendation.

METHODS

This was a 3-arm pragmatic randomized trial comparing telephone, secure messaging, and mailed letter outreach. The setting was Kaiser Permanente Northern California, a large integrated healthcare system. Participants were patients 54-70 years of age with 1-2 small (<10 mm) tubular adenomas at baseline colonoscopy, due for 5-year surveillance in 2022, without high-risk conditions, and with access to all 3 outreach modalities. Patients were randomly assigned to the outreach arm (telephone [n = 200], secure message [n = 203], and mailed letter [n = 201]) stratified by age, sex, and race/ethnicity. Outreach in each arm was performed by trained medical assistants (unblinded) communicating in English with 1 reminder attempt at 2-4 weeks. Participants could change their assigned interval to 10 years or continue their planned 5-year interval.

RESULTS

Sixty-day response rates were higher for telephone (64.5%) and secure messaging outreach (51.7%) vs mailed letter (31.3%). Also, more patients adopted the 10-year surveillance interval in the telephone (37.0%) and secure messaging arms (32.0%) compared with mailed letter (18.9%) and rate differences were significant for telephone (18.1%; 97.5% confidence interval: 8.3%-27.9%) and secure message outreach (13.1%; 97.5% confidence interval: 3.5%-22.7%) vs mailed letter outreach.

CONCLUSIONS

Telephone and secure messaging were more effective than mailed letter outreach for de-implementing outdated colonoscopy surveillance recommendations among individuals with a history of low-risk adenomas in an integrated healthcare setting. (ClinicalTrials.gov, Number: NCT05389397).

Evaluation and Management of Malignant Colorectal Polyps

The detection rate of dysplastic colorectal polyps has significantly increased with improved screening programs. Treatment of dysplastic polyps attempt to limit morbidity of a procedure while also considering the risk of occult lymph node metastasis. Therefore, a variety of methods have been developed to predict the rate of lymph node metastasis to help identify the optimal treatment of patients. These include both the endoscopic and pathologic assessment of the lesion. In order to reduce the morbidity of surgery for patients with low-risk lesions, multiple endoscopic therapies have been developed, including endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic intermuscular dissection, and transanal endoscopic surgery.

Integrating Clinical Guidelines With ChatGPT-4 Enhances Its' Skills

Navigating clinical guidelines can be complex for real-time health care decision making. Our study evaluates the chat generative prerained transformer (ChatGPT)-4 in improving responses to clinical questions by integrating guidelines on Clostridioides difficile infection and colon polyp surveillance. We assessed ChatGPT-4's responses to questions before and after guideline integration, noting a clear improvement in accuracy. ChatGPT-4 provided guideline-aligned answers consistently. Further analysis showed its ability to summarize information from conflicting guidelines, highlighting its utility in complex clinical scenarios. The findings suggest that large language models such as ChatGPT-4 can enhance clinical decision making and patient education by providing quick, conversational, and accurate responses. This approach opens a path for using artificial intelligence to deliver reliable responses in health care, supporting clinicians in real-time decision making and improving patient care.

Effect of an online educational module incorporating real-time feedback on accuracy of polyp sizing in trainees: a randomized controlled trial

BACKGROUND

Although polyp size dictates surveillance intervals, endoscopists often estimate polyp size inaccurately. We hypothesized that an intervention providing didactic instruction and real-time feedback could significantly improve polyp size classification.

METHODS

We conducted a multicenter randomized controlled trial to evaluate the impact of different components of an online educational module on polyp sizing. Participants were randomized to control (no video, no feedback), video only, feedback only, or video + feedback. The primary outcome was accuracy of polyp size classification into clinically relevant categories (diminutive [1-5mm], small [6-9mm], large [≥10mm]). Secondary outcomes included accuracy of exact polyp size (inmm), learning curves, and directionality of inaccuracy (over- vs. underestimation).

RESULTS

36 trainees from five training programs provided 1360 polyp size assessments. The feedback only (80.1%, P=0.01) and video + feedback (78.9%, P=0.02) groups had higher accuracy of polyp size classification compared with controls (71.6%). There was no significant difference in accuracy between the video only group (74.4%) and controls (P=0.42). Groups receiving feedback had higher accuracy of exact polyp size (inmm) and higher peak learning curves. Polyps were more likely to be overestimated than underestimated, and 29.3% of size inaccuracies impacted recommended surveillance intervals.

CONCLUSIONS

Our online educational module significantly improved polyp size classification. Real-time feedback appeared to be a critical component in improving accuracy. This scalable and no-cost educational module could significantly decrease under- and overutilization of colonoscopy, improving patient outcomes while increasing colonoscopy access.

Molecular Signatures for Microbe-Associated Colorectal Cancers

Background

Genetic factors and microbial imbalances play crucial roles in colorectal cancers (CRCs), yet the impact of infections on cancer initiation remains poorly understood. While bioinformatic approaches offer valuable insights, the rising incidence of CRCs creates a pressing need to precisely identify early CRC events. We constructed a network model to identify continuum states during CRC initiation spanning normal colonic tissue to pre-cancer lesions (adenomatous polyps) and examined the influence of microbes and host genetics.

Methods

A Boolean network was built using a publicly available transcriptomic dataset from healthy and adenoma affected patients to identify an invariant Microbe-Associated Colorectal Cancer Signature (MACS). We focused on Fusobacterium nucleatum ( Fn ), a CRC-associated microbe, as a model bacterium. MACS-associated genes and proteins were validated by RT-qPCR, RNA seq, ELISA, IF and IHCs in tissues and colon-derived organoids from genetically predisposed mice ( CPC-APC Min+/- ) and patients (FAP, Lynch Syndrome, PJS, and JPS).

Results

The MACS that is upregulated in adenomas consists of four core genes/proteins: CLDN2/Claudin-2 (leakiness), LGR5/leucine-rich repeat-containing receptor (stemness), CEMIP/cell migration-inducing and hyaluronan-binding protein (epithelial-mesenchymal transition) and IL8/Interleukin-8 (inflammation). MACS was induced upon Fn infection, but not in response to infection with other enteric bacteria or probiotics. MACS induction upon Fn infection was higher in CPC-APC Min+/- organoids compared to WT controls. The degree of MACS expression in the patient-derived organoids (PDOs) generally corresponded with the known lifetime risk of CRCs.

Conclusions

Computational prediction followed by validation in the organoid-based disease model identified the early events in CRC initiation. MACS reveals that the CRC-associated microbes induce a greater risk in the genetically predisposed hosts, suggesting its potential use for risk prediction and targeted cancer prevention.

Maximizing scarce colonoscopy resources: the crucial role of stool-based tests

During the COVID-19 pandemic, health systems, including federally qualified health centers, experienced disruptions in colorectal cancer (CRC) screening. National organizations called for greater use of at-home stool-based testing followed by colonoscopy for those with abnormal test results to limit (in-person) colonoscopy exams to people with acute symptoms or who were high risk. This stool-test-first strategy may also be useful for adults with low-risk adenomas who are due for surveillance colonoscopy. We argue that colonoscopy is overused as a first-line screening method in low- and average-risk adults and as a surveillance tool among adults with small adenomas. Yet, simultaneously, many people do not receive much-needed colonoscopies. Delivering the right screening tests at intervals that reduce the risk of CRC, while minimizing patient inconvenience and procedural risks, can strengthen health-care systems. Risk stratification could improve efficiency of CRC screening, but because models that adequately predict risk are years away from clinical use, we need to optimize use of currently available technology-that is, low-cost fecal testing followed by colonoscopy for those with abnormal test results. The COVID-19 pandemic highlighted the urgent need to adapt to resource constraints around colonoscopies and showed that increased use of stool-based testing was possible. Learning how to adapt to such constraints without sacrificing patients' health, particularly for patients who receive care at federally qualified health centers, should be a priority for CRC prevention research.

Colorectal cancer: incidence, risk factors, and screening

The analysis of the current literature data characterizing the incidence, risk factors and screening methods of colorectal cancer (CRC) is presented. In recent years, dynamics of CRC epidemiological indicators have been unfavorable worldwide. The CRC incidence in Russia is high and reaches 30.7 per 100 thousand population in men, among women — 20.9 per 100 thousand population. The leading risk factors for this pathology include male sex, age older than 45—50 years, detection of adenomatous polyps in the intestines, the presence of close relatives with CRC, obesity, tobacco smoking, alcohol use, consumption of red and processed meat. The leading CRC screening methods are highly sensitive stool occult blood tests and colonoscopy. It is advisable to increase the use of screening and the development of preventive measures to reduce the incidence of CRC in Russia.

Analysis of the Characteristics of Coexisting Lesions in Colorectal Cancer Patients in an International Study: A Subgroup Analysis of the ATLAS Trial

INTRODUCTION

We investigated coexisting lesion types in patients with invasive colorectal cancer (CRC) in a multinational study for comprehending the adenoma-carcinoma and serrated pathway about the development of CRC.

METHODS

We retrospectively reviewed 3,050 patients enrolled in the international randomized controlled trial (ATLAS study) to evaluate the colorectal polyp detection performance of image-enhanced endoscopy in 11 institutions in four Asian countries/regions. In the current study, as a subgroup analysis of the ATLAS study, 92 CRC patients were extracted and compared to 2,958 patients without CRC to examine the effects of age, sex, and coexisting lesion types (high-grade adenoma [HGA], low-grade adenoma with villous component [LGAV], 10 adenomas, adenoma ≥10 mm, sessile serrated lesions [SSLs], and SSLs with dysplasia [SSLD]). Additional analyses of coexisting lesion types were performed according to sex and location of CRC (right- or left-sided).

RESULTS

A multivariate analysis showed that HGA (odds ratio [95% confidence interval] 4.29 [2.16-8.18]; p < 0.01), LGAV (3.02 [1.16-7.83], p = 0.02), and age (1.04 [1.01-1.06], p = 0.01) were independently associated with CRC. According to sex, the coexisting lesion types significantly associated with CRC were LGAV (5.58 [1.94-16.0], p < 0.01) and HGA (4.46 [1.95-10.20], p < 0.01) in males and HGA (4.82 [1.47-15.80], p < 0.01) in females. Regarding the location of CRC, SSLD (21.9 [1.31-365.0], p = 0.03) was significant for right-sided CRC, and HGA (5.22 [2.39-11.4], p < 0.01) and LGAV (3.46 [1.13-10.6], p = 0.02) were significant for left-sided CRC.

CONCLUSIONS

The significant coexisting lesions in CRC differed according to sex and location. These findings may contribute to comprehending the pathogenesis of CRC.

Social determinants of health influencing the adherence to post-endoscopic mucosal resection surveillance

BACKGROUND AND AIMS

Colorectal cancer (CRC) is a global health challenge, particularly in Alabama, where the incidence rates exceed national averages. This study investigated the factors influencing adherence to post-endoscopic mucosal resection (EMR) colonoscopies, focusing on travel distance and socioeconomic status. This study aimed to provide evidence-based insights to improve patient care in CRC management.

METHODS

This retrospective study in a tertiary care referral center analyzed 465 patients who underwent EMR. The data included demographics, clinical details, and travel-related variables. Descriptive statistics, logistic regression, and spatial analysis were used to assess the factors affecting adherence.

RESULTS

Of 465 patients, 36.6 % had adequate follow-up, 21.8 % had inadequate follow-up, and 41.6 % were lost to follow-up. Noteworthy demographic variations were observed, with median ages differing across adherence groups. Traveled distances showcased compelling insights, indicating a median distance of 22.2 miles for adequate follow-up, 15.7 miles for inadequate follow-up, and 31.6 miles for the lost-to-follow-up group (p<0.001). Longer travel distances were associated with better adherence. Longer travel distances from the hospital were associated with significantly lower odds of inadequate follow-up: 10-25 miles OR:0.29, 25-85 miles OR:0.35, and >80 miles OR:0.24 compared to the first quartile (<10 miles). Socioeconomic factors, particularly educational attainment, significantly influenced the follow-up rates.

CONCLUSIONS

This study revealed suboptimal post-EMR follow-up rates and underscored the impact of travel distance and socioeconomic factors. Targeted interventions addressing distance-related barriers can enhance treatment adherence and ensure timely CRC surveillance after EMR. Further research is needed in diverse healthcare settings.

A real-time deep learning-based system for colorectal polyp size estimation by white-light endoscopy: development and multicenter prospective validation

BACKGROUND

The choice of polypectomy device and surveillance intervals for colorectal polyps are primarily decided by polyp size. We developed a deep learning-based system (ENDOANGEL-CPS) to estimate colorectal polyp size in real time.

METHODS

ENDOANGEL-CPS calculates polyp size by estimating the distance from the endoscope lens to the polyp using the parameters of the lens. The depth estimator network was developed on 7297 images from five virtually produced colon videos and tested on 730 images from seven virtual colon videos. The performance of the system was first evaluated in nine videos of a simulated colon with polyps attached, then tested in 157 real-world prospective videos from three hospitals, with the outcomes compared with that of nine endoscopists over 69 videos. Inappropriate surveillance recommendations caused by incorrect estimation of polyp size were also analyzed.

RESULTS

The relative error of depth estimation was 11.3% (SD 6.0%) in successive virtual colon images. The concordance correlation coefficients (CCCs) between system estimation and ground truth were 0.89 and 0.93 in images of a simulated colon and multicenter videos of 157 polyps. The mean CCC of ENDOANGEL-CPS surpassed all endoscopists (0.89 vs. 0.41 [SD 0.29]; P<0.001). The relative accuracy of ENDOANGEL-CPS was significantly higher than that of endoscopists (89.9% vs. 54.7%; P<0.001). Regarding inappropriate surveillance recommendations, the system's error rate is also lower than that of endoscopists (1.5% vs. 16.6%; P<0.001).

CONCLUSIONS

ENDOANGEL-CPS could potentially improve the accuracy of colorectal polyp size measurements and size-based surveillance intervals.

Screening for Colorectal Cancer

Colorectal cancer (CRC) is the second leading cause of cancer death. Screening has been proven to reduce both cancer incidence and cancer-related mortality. Various screening tests are available, each with their own advantages and disadvantages and varying levels of evidence to support their use. Clinicians should offer CRC screening to average-risk persons aged 50 to 75 years; starting screening at age 45 years remains controversial. Screening may be beneficial in select persons aged 76 to 85 years, based on their overall health and screening history. Offering a choice of screening tests or sequentially offering an alternate test for those who do not complete screening can significantly increase participation.

Development and External Validation of a Prediction Model for Colorectal Cancer Among Patients Awaiting Surveillance Colonoscopy Following Polypectomy

Background and Aims

Demand for surveillance colonoscopy can sometimes exceed capacity, such as during and following the coronavirus disease 2019 pandemic, yet no tools exist to prioritize the patients most likely to be diagnosed with colorectal cancer (CRC) among those awaiting surveillance colonoscopy. We developed a multivariable prediction model for CRC at surveillance comparing performance to a model that assigned patients as low or high risk based solely on polyp characteristics (guideline-based model).

Methods

Logistic regression was used for model development among patients receiving surveillance colonoscopy in 2014-2019. Candidate predictors included index colonoscopy indication, findings, and endoscopist adenoma detection rate, and patient and clinical characteristics at surveillance. Patients were randomly divided into model development (n = 36,994) and internal validation cohorts (n = 15,854). External validation was performed on 30,015 patients receiving surveillance colonoscopy in 2020-2022, and the multivariable model was then updated and retested.

Results

One hundred fourteen, 43, and 71 CRCs were detected at surveillance in the 3 cohorts, respectively. Polyp size ≥10 mm, adenoma detection rate <32.5% or missing, patient age, and ever smoked tobacco were significant CRC predictors; this multivariable model outperformed the guideline-based model (internal validation cohort area under the receiver-operating characteristic curve: 0.73, 95% confidence interval (CI): 0.66-0.81 vs 0.52, 95% CI: 0.45-0.60). Performance declined at external validation but recovered with model updating (operating characteristic curve: 0.72 95% CI: 0.66-0.77).

Conclusion

When surveillance colonoscopy demand exceeds capacity, a prediction model featuring common clinical predictors may help prioritize patients at highest risk for CRC among those awaiting surveillance. Also, regular model updates can address model performance drift.

A Cell-free DNA Blood-Based Test for Colorectal Cancer Screening

BACKGROUND

Colorectal cancer is the third most diagnosed cancer in adults in the United States. Early detection could prevent more than 90% of colorectal cancer-related deaths, yet more than one third of the screening-eligible population is not up to date with screening despite multiple available tests. A blood-based test has the potential to improve screening adherence, detect colorectal cancer earlier, and reduce colorectal cancer-related mortality.

METHODS

We assessed the performance characteristics of a cell-free DNA (cfDNA) blood-based test in a population eligible for colorectal cancer screening. The coprimary outcomes were sensitivity for colorectal cancer and specificity for advanced neoplasia (colorectal cancer or advanced precancerous lesions) relative to screening colonoscopy. The secondary outcome was sensitivity to detect advanced precancerous lesions.

RESULTS

The clinical validation cohort included 10,258 persons, 7861 of whom met eligibility criteria and were evaluable. A total of 83.1% of the participants with colorectal cancer detected by colonoscopy had a positive cfDNA test and 16.9% had a negative test, which indicates a sensitivity of the cfDNA test for detection of colorectal cancer of 83.1% (95% confidence interval [CI], 72.2 to 90.3). Sensitivity for stage I, II, or III colorectal cancer was 87.5% (95% CI, 75.3 to 94.1), and sensitivity for advanced precancerous lesions was 13.2% (95% CI, 11.3 to 15.3). A total of 89.6% of the participants without any advanced colorectal neoplasia (colorectal cancer or advanced precancerous lesions) identified on colonoscopy had a negative cfDNA blood-based test, whereas 10.4% had a positive cfDNA blood-based test, which indicates a specificity for any advanced neoplasia of 89.6% (95% CI, 88.8 to 90.3). Specificity for negative colonoscopy (no colorectal cancer, advanced precancerous lesions, or nonadvanced precancerous lesions) was 89.9% (95% CI, 89.0 to 90.7).

CONCLUSIONS

In an average-risk screening population, this cfDNA blood-based test had 83% sensitivity for colorectal cancer, 90% specificity for advanced neoplasia, and 13% sensitivity for advanced precancerous lesions. (Funded by Guardant Health; ECLIPSE ClinicalTrials.gov number, NCT04136002.).

Sporadic Polyps of the Colorectum

Colorectal polyps are common, and their diagnosis and classification represent a major component of gastrointestinal pathology practice. The majority of colorectal polyps represent precursors of either the chromosomal instability or serrated neoplasia pathways to colorectal carcinoma. Accurate reporting of these polyps has major implications for surveillance and thus for cancer prevention. In this review, we discuss the key histologic features of the major colorectal polyps with a particular emphasis on diagnostic pitfalls and areas of contention.

Endoscopic Removal of Premalignant Lesions Reduces Long-Term Colorectal Cancer Risk: Results From the Japan Polyp Study

BACKGROUND & AIMS

To date, no regional evidence of long-term colorectal cancer (CRC) risk reduction after endoscopic premalignant lesion removal has been established. We aimed to analyze this over a long-term follow-up evaluation.

METHODS

This was a prospective cohort study of participants from the Japan Polyp Study conducted at 11 Japanese institutions. Participants underwent scheduled follow-up colonoscopies after a 2-round baseline colonoscopy process. The primary outcome was CRC incidence after randomization. The observed/expected ratio of CRC was calculated using data from the population-based Osaka Cancer Registry. Secondary outcomes were the incidence and characteristics of advanced neoplasia (AN).

RESULTS

A total of 1895 participants were analyzed. The mean number of follow-up colonoscopies and the median follow-up period were 2.8 years (range, 1-15 y) and 6.1 years (range, 0.8-11.9 y; 11,559.5 person-years), respectively. Overall, 4 patients (all males) developed CRCs during the study period. The observed/expected ratios for CRC in all participants, males, and females, were as follows: 0.14 (86% reduction), 0.18, and 0, respectively, and 77 ANs were detected in 71 patients (6.1 per 1000 person-years). Of the 77 ANs detected, 31 lesions (40.3%) were laterally spreading tumors, nongranular type. Nonpolypoid colorectal neoplasms (NP-CRNs), including flat (<10 mm), depressed, and laterally spreading, accounted for 59.7% of all detected ANs. Furthermore, 2 of the 4 CRCs corresponded to T1 NP-CRNs.

CONCLUSIONS

Endoscopic removal of premalignant lesions, including NP-CRNs, effectively reduced CRC risk. More than half of metachronous ANs removed by surveillance colonoscopy were NP-CRNs. The Japan Polyp Study: University Hospital Medical Information Network Clinical Trial Registry: University Hospital Medical Information Network Clinical Trial Registry, C000000058; cohort study: UMIN000040731.

Accuracy in Polyp Size Measurement Among Surgeons, Gastroenterologists, Trainees, and Experts: A Prospective Video-Based Study

INTRODUCTION

Polyp size determination plays an important role in endoscopic decision making and follow-up determination. However, there is a lack of knowledge of endoscopist accuracy for polyp sizing and efficacy of available tools for size measurement. Our aim was to compare the accuracy of visual assessment, snare, forceps, and virtual scale endoscope (VSE) in estimating polyp size among a diverse group of endoscopists.

METHODS

We conducted a prospective video-based study. One hundred twenty polyps measured and recorded along with all available measurement tools were randomized to visual assessment, snare, forceps, or VSE group. Eleven endoscopists conducted video-based measurement using the randomized measurement tool. Primary outcome was relative accuracy in polyp size measurement compared with caliper measurement immediately postresection.

RESULTS

One thousand three hundred twenty measurements were performed. VSE had statistically significantly higher relative accuracy when compared to forceps (79.3 vs 71.3%; P < 0.0001). Forceps had statistically significantly higher relative accuracy when compared to visual assessment (71.3 vs 63.6%; P = 0.0036). There was no statistically significant difference when comparing visual assessment and snare-based measurements (63.6 vs 62.8%; P = 0.797). Overall, 21.5% of polyps >5 mm were misclassified as ≤5 mm and 17.3% of polyps ≥10 mm were misclassified as <10 mm. VSE had the lowest percentage of polyps >5 mm misclassified as ≤5 mm (2.6%), polyps ≤5 mm misclassified as >5 mm (5.1%), and polyps <10 mm misclassified as ≥10 mm (1.7%).

DISCUSSION

Visual size estimation of polyps is inaccurate independently of training level, sex, and specialty. Size measurement accuracy can be improved using forceps and yields the highest relative accuracy when an adaptive scale technology is used.

Comparison of Artificial Intelligence With Other Interventions to Improve Adenoma Detection Rate for Colonoscopy: A Network Meta-analysis

INTRODUCTION

Recent randomized controlled trials (RCTs) and meta-analysis have demonstrated improved adenoma detection rate (ADR) for colonoscopy with artificial intelligence (AI) compared with high-definition (HD) colonoscopy without AI. We aimed to perform a systematic review and network meta-analysis of all RCTs to assess the impact of AI compared with other endoscopic interventions aimed at increasing ADR such as distal attachment devices, dye-based/virtual chromoendoscopy, water-based techniques, and balloon-assisted devices.

METHODS

A comprehensive literature search of PubMed/Medline, Embase, and Cochrane was performed through May 6, 2022, to include RCTs comparing ADR for any endoscopic intervention mentioned above. Network meta-analysis was conducted using a frequentist approach and random effects model. Relative risk (RR) and 95% CI were calculated for proportional outcome.

RESULTS

A total of 94 RCTs with 61,172 patients (mean age 59.1±5.2 y, females 45.8%) and 20 discrete study interventions were included. Network meta-analysis demonstrated significantly improved ADR for AI compared with autofluorescence imaging (RR: 1.33, CI: 1.06 to 1.66), dye-based chromoendoscopy (RR: 1.22, CI: 1.06 to 1.40), endocap (RR: 1.32, CI: 1.17 to 1.50), endocuff (RR: 1.19, CI: 1.04 to 1.35), endocuff vision (RR: 1.26, CI: 1.13 to 1.41), endoring (RR: 1.30, CI: 1.10 to 1.52), flexible spectral imaging color enhancement (RR: 1.26, CI: 1.09 to 1.46), full-spectrum endoscopy (RR: 1.40, CI: 1.19 to 1.65), HD (RR: 1.41, CI: 1.28 to 1.54), linked color imaging (RR: 1.21, CI: 1.08 to 1.36), narrow band imaging (RR: 1.33, CI: 1.18 to 1.48), water exchange (RR: 1.22, CI: 1.06 to 1.42), and water immersion (RR: 1.47, CI: 1.19 to 1.82).

CONCLUSIONS

AI demonstrated significantly improved ADR when compared with most endoscopic interventions. Future RCTs directly assessing these associations are encouraged.

Management after non-curative endoscopic resection of T1 rectal cancer

Since the introduction of population-based screening, increasing numbers of T1 rectal cancers are detected and removed by local endoscopic resection. Patients can be cured with endoscopic resection alone, but there is a possibility of residual tumor cells remaining after the initial resection. These can be located intraluminally at the resection site or extraluminally in the form of (lymph node) metastases. To decrease the risk of residual cells progressing towards more advanced disease, additional treatment is usually needed. However, with the currently available risk stratification models, it remains challenging to determine who should and should not be further treated after non-curative endoscopic resection. In this review, the different management strategies for patients with non-curatively treated T1 rectal cancers are discussed, along with the available evidence for each strategy and relevant considerations for clinical decision making. Furthermore, we provide practical guidance on the management and surveillance following non-curative endoscopic resection of T1 rectal cancer.

Macrophage Inflammatory Proteins (MIPs) Contribute to Malignant Potential of Colorectal Polyps and Modulate Likelihood of Cancerization Associated with Standard Risk Factors

Better understanding of molecular changes leading to neoplastic transformation is prerequisite to optimize risk assessment and chemopreventive and surveillance strategies. Data on macrophage inflammatory proteins (MIPs) in colorectal carcinogenesis are scanty and their clinical relevance remains unknown. Therefore, transcript and protein expression of CCL3, CCL4, CXCL2, and CCL19 were determined in 173 and 62 patients, respectively, using RT-qPCR and immunohistochemistry with reference to polyps' characteristics. The likelihood of malignancy was modeled using probit regression. With the increasing malignancy potential of hyperplastic-tubular-tubulo-villous-villous polyps, the expression of CCL3, CCL4, and CCL19 in lesions decreased. CCL19 expression decreased also in normal mucosa while that of CXCL2 increased. Likewise, lesion CCL3 and lesion and normal mucosa CCL19 decreased and normal CXCL2 increased along the hyperplasia-low-high dysplasia grade. The bigger the lesion, the lower CCL3 and higher CXCL2 in normal mucosa. Singular polyps had higher CCL3, CCL4, and CCL19 levels in normal mucosa. CCL3, CCL4 and CXCL2 modulated the likelihood of malignancy associated with traditional risk factors. There was no correlation between the protein and mRNA expression of CCL3 and CCL19. In summary, the polyp-adjacent mucosa contributes to gaining potential for malignancy by polyps. MIPs may help in specifying cancerization probability estimated based on standard risk factors.

Demographic Comparison of the Burden of Endoscopically Screenable Cancers in the United States

Background and Aims

Gastrointestinal cancer incidence varies by race and ethnicity. In the United States (US), there are screening guidelines for esophageal cancer (EC) and colorectal cancer (CRC), but not gastric cancer (GC). We compared GC, CRC, and EC incidence among the most populous racial and ethnic groups to inform US interception strategies.

Methods

We used SEER∗Stat to compare GC, CRC, and EC incidence rates across non-Hispanic White (NHW), non-Hispanic Black, Hispanic, and the 8 largest Asian American populations using the Surveillance, Epidemiology, and End Results 9 registries (2010-2014).

Results

Noncardia GC incidence was highest among Korean (18.7 cases per 100,000) and lowest among NHW (1.4 cases per 100,000) Americans. CRC incidence was highest among non-Hispanic Black, Southeast Asian, and Japanese (35.9, 34.2, and 33.8 per 100,000, respectively) Americans and lowest among South Asian Americans (18.9 per 100,000). EC incidence was greatest in NHW (4.7 per 100,000) and lowest in Filipino (1.2 per 100,000) Americans. The incidence of noncardia GC slightly exceeded colon cancer in Korean American men (25.5 vs 22.4 per 100,000). GC surpassed EC incidence in all non-White racial and ethnic groups.

Conclusion

The burden of GC, CRC, and EC differs based on race and ethnicity. Non-White racial and ethnic groups experience a disproportionate burden of GC for which systematic programs for cancer interception, similar to CRC and EC, are needed.

Computer-aided polyp characterization in colonoscopy: sufficient performance or not?

Computer-assisted polyp characterization (computer-aided diagnosis, CADx) facilitates optical diagnosis during colonoscopy. Several studies have demonstrated high sensitivity and specificity of CADx tools in identifying neoplastic changes in colorectal polyps. To implement CADx tools in colonoscopy, there is a need to confirm whether these tools satisfy the threshold levels that are required to introduce optical diagnosis strategies such as "diagnose-and-leave," "resect-and-discard" or "DISCARD-lite." In this article, we review the available data from prospective trials regarding the effect of multiple CADx tools and discuss whether they meet these thresholds.

Population health outcomes of blood-based screening for colorectal cancer in comparison to current screening modalities: insights from a discrete-event simulation model incorporating longitudinal adherence

AIM

Insufficient adherence to colorectal cancer (CRC) screening impedes individual and population health benefits, with about one-third of individuals non-adherent to available screening options. The impact of poor adherence is inadequately considered in most health economics models, limiting the evaluation of real-world population-level screening outcomes. This study introduces the CAN-SCREEN (Colorectal cANcer SCReening Economics and adherENce) model, utilizing real-world adherence scenarios to assess the effectiveness of a blood-based test (BBT) compared to existing strategies.

MATERIALS AND METHODS

The CAN-SCREEN model evaluates various CRC screening strategies per 1,000 screened individuals for ages 45-75. Adherence is modeled in two ways: (1) full adherence and (2) longitudinally declining adherence. BBT performance is based on recent pivotal trial data while existing strategies are informed using literature. The full adherence model is calibrated using previously published Cancer Intervention and Surveillance Modeling Network (CISNET) models. Outcomes, including life-years gained (LYG), CRC cases averted, CRC deaths averted, and colonoscopies, are compared to no screening.

RESULTS

Longitudinal adherence modeling reveals differences in the relative ordering of health outcomes and resource utilization, as measured by the number of colonoscopies performed per 1,000, between screening modalities. BBT outperforms the fecal immunochemical test (FIT) and the multitarget stool DNA (mtsDNA) test with more CRC deaths averted (13) compared to FIT and mtsDNA (7, 11), more CRC cases averted (27 vs. 16, 22) and higher LYG (214 vs. 157, 199). BBT yields fewer CRC deaths averted compared to colonoscopy (13, 15) but requires fewer colonoscopies (1,053 vs. 1,928).

LIMITATIONS

Due to limited data, the CAN-SCREEN model with longitudinal adherence leverages evidence-informed assumptions for the natural history and real-world longitudinal adherence to screening.

CONCLUSIONS

The CAN-SCREEN model demonstrates that amongst non-invasive CRC screening strategies, those with higher adherence yield more favorable health outcomes as measured by CRC deaths averted, CRC cases averted, and LYG.

Pathologic Features of Primary Colon, Rectal, and Anal Malignancies

In USA, colorectal cancer is the third most commonly diagnosed cancer in men, second in women, as well as the third leading cause of cancer deaths (Siegel et al. in Cancer J Clin 73:1-112, 2023 [109]). Worldwide, colorectal cancer is the second leading cause of death and causes almost 916,000 deaths each year (Ferlay in Global cancer observatory: cancer today. International Agency for Research on Cancer, Lyon, 2020 [28]). Fortunately, due to the colon's surgical and endoscopic accessibility and functional redundancy, colorectal cancer is very treatable. Colonoscopic surveillance has the potential for not only providing tissue for the diagnosis of precancerous polyps and invasive carcinoma, but also preventing development of invasive carcinoma by the removal of precancerous lesions. This chapter discusses the clinical and pathologic features of the spectrum of epithelial, hematolymphoid, and mesenchymal malignant tumors of the colon, rectum, appendix, and anus.

Analysis of the Current Status and Factors Influencing Compliance with Colonoscopic Monitoring After Endoscopic Surgery for Advanced Colorectal Adenoma

Background

Advanced colorectal adenomas are at a risk of malignant transformation following endoscopic resection, and colonoscopic monitoring interval after polypectomy have been widely used. This study aims to investigate the prevailing state of compliance with postoperative colonoscopic surveillance among patients with advanced colorectal adenomas and its' influencing factors at Affiliated Hospital of Jiangnan University between November 2020 and April 2021.

Methods

A retrospective analysis was conducted on patients who underwent endoscopic treatment for ACA at Affiliated Hospital of Jiangnan University from November 2020 to April 2021. Compliance with postoperative colonoscopic surveillance was assessed based on established guidelines. Factors such as sociodemographic features, medical histories, and health beliefs were analyzed to determine their influence on compliance. Univariate analysis, survival analysis, and multi-factor Cox regression analysis were used for statistical evaluation.

Results

A total of 511 patients were included in the study. The compliance rate was found to be 43.2%. The univariate analysis indicated that factors such as gender, education level, work status, type of health insurance, place of residence, marital status, type of consultation, presence of gastrointestinal symptoms, number of polyps, and the maximum diameter of polyps significantly affected compliance. Multi-factor Cox regression analysis revealed that female gender, absence of gastrointestinal symptoms, outpatient endoscopic treatment, and solitary polyps were independent factors influencing compliance. Reasons for poor compliance included underestimating the severity of the disease, fear of colonoscopy, and procedural complexities.

Conclusion

Patients with advanced colorectal adenomas had poor compliance with postoperative colonoscopy monitoring. Tailored health education programs should be designed, targeting women, outpatients undergoing endoscopic procedures, and patients with solitary polyps to enhance their compliance with colonoscopy monitoring.

Skin Cancers in Medicare Beneficiaries With Actinic Keratoses

Importance

Actinic keratoses (AK) are common premalignant skin lesions with a small risk of progressing to cutaneous squamous cell carcinoma (SCC). There is some evidence that patients with AKs also have increased risks of other skin cancers beyond SCC. However, the absolute risks of skin cancer in patients with AKs are unknown.

Objective

To calculate the absolute and relative risks of future skin cancer in Medicare beneficiaries with AKs.

Design, Setting, and Participants

This retrospective cohort study was performed using a deidentified, random sample of 4 999 999 fee-for-service Medicare beneficiaries from 2009 through 2018. Patients with treated AKs were included, and patients with seborrheic keratoses (SKs) were included as a comparator group. All patients were required to have at least 1 year between data set entry and first AK or SK. Patients with a history of skin cancer were excluded. Data were analyzed from September 2022 to March 2023.

Main Outcomes and Measures

Outcomes were first surgically treated skin cancer, including keratinocyte carcinoma (including SCC and basal cell carcinoma [BCC]) and melanoma. The absolute risks of skin cancer in patients with AKs were evaluated. Skin cancer risks in patients with AKs were compared with patients with SKs using adjusted competing risks regression.

Results

A total of 555 945 patients with AKs (mean [SD] age, 74.0 [7.4] years; 55.4% female) and 481 024 patients with SKs (mean [SD] age, 73.3 [7.3] years; 72.4% female) were included. The absolute risk of skin cancer after a first AK was 6.3% (95% CI, 6.3%-6.4%) at 1 year, 18.4% (95% CI, 18.3%-18.5%) at 3 years, and 28.5% (95% CI, 28.4%-28.7%) at 5 years. Patients with AKs had increased risk of skin cancer compared with patients with SKs (any skin cancer: adjusted hazard ratio [aHR], 2.17; 95% CI, 2.15-2.19; keratinocyte carcinoma: aHR, 2.20; 95% CI, 2.18-2.22; SCC: aHR, 2.63; 95% CI, 2.59-2.66; BCC: aHR, 1.85; 95% CI, 1.82-1.87; and melanoma: aHR, 1.67; 95% CI, 1.60-1.73).

Conclusions and Relevance

In this cohort study, older patients with AKs had substantial absolute risks, as well as elevated relative risks, of skin cancer. AKs may be clinical markers of UV exposure and increased skin cancer risk, including SCC, BCC, and melanoma. However, guidelines are lacking for follow-up skin cancer surveillance in patients with AKs. Efforts to develop evidence-based recommendations for skin cancer surveillance in patients with AKs are paramount.

Differential impact of test performance characteristics on burden-to-benefit tradeoffs for blood-based colorectal cancer screening: A microsimulation analysis

OBJECTIVES

To inform the development and evaluation of new blood-based colorectal cancer (CRC) screening tests satisfying minimum United States (US) coverage criteria, we estimated the impact of the different test performance characteristics on long-term testing benefits and burdens.

METHODS

A novel CRC-Microsimulation of Adenoma Progression and Screening (CRC-MAPS) model was developed, validated, then used to assess different screening tests for CRC. We compared multiple, hypothetical blood-based CRC screening tests satisfying minimum coverage criteria of 74% CRC sensitivity and 90% specificity, to measure how changes in a test's CRC sensitivity, specificity, and adenoma sensitivity (sizes 1-5 mm, 6-9 mm, ≥10 mm) affect total number of colonoscopies (COL), CRC incidence reduction (IR), CRC mortality reduction (MR), and burden-to-benefit ratios (incremental COLs per percentage-point increase in IR or MR).

RESULTS

A blood test meeting minimum US coverage criteria for performance characteristics resulted in 1576 lifetime COLs per 1000 individuals, 46.7% IR and 59.2% MR compared to no screening. Tests with increased CRC sensitivity of 99% ( + 25%) vs. increased ≥10 mm adenoma sensitivity of 13.6% ( + 3.6%) both yielded the same MR, 62.7%. Test benefits improved the most with increases in all-size adenoma sensitivity, then size-specific adenoma sensitivities, then specificity and CRC sensitivity, while increases in specificity or ≥10 mm adenoma sensitivity resulted in the most favorable burden-to-benefit tradeoffs (ratios <11.5).

CONCLUSIONS

Burden-to-benefit ratios for blood-based CRC screening tests differ by performance characteristic, with the most favorable tradeoffs resulting from improvements in specificity and ≥10 mm adenoma sensitivity.

Risk factors for metachronous colorectal cancer and advanced neoplasia following primary colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Identifying risk factors for metachronous colorectal cancer (CRC) and metachronous advanced neoplasia could be useful for guiding surveillance. We conducted a systematic review and meta-analysis to investigate risk factors for metachronous CRC and advanced neoplasia.

METHODS

Searches were conducted in MEDLINE, Embase, Web of Science and Cochrane Central Registry of Controlled Trials for articles (searching period: 1945 to Feburary, 2021) that reported the results of an association between any factor and metachronous advanced neoplasia or metachronous CRC. There were no restrictions on the publication date or language. Random effects models were fitted to estimate the combined association between the risk factors and metachronous CRC or advanced neoplasia. The Risk of Bias In Non-Randomised Studies of Interventions tool (ROBINS-I) was used to assess the risk of bias of included studies.

RESULTS

In total, 22 observational studies with 625,208 participants were included in the systematic review and meta-analysis. Of these, 13 studies investigated risk factors for metachronous CRC and 9 for advanced neoplasia. The risks of metachronous CRC or advanced neoplasia were higher if the first CRC was diagnosed in the presence of a synchronous advanced lesion (pooled risk ratio (RR) from 3 studies: 3.61, 95% confidence interval (CI): 1.44-9.05; and pooled RR from 8 studies: 2.77, 95% CI: 2.23-3.43, respectively). The risk of metachronous CRC was lower, but the risk of metachronous advanced neoplasia was higher if the first CRC was distal (compared with proximal) (pooled RR from 3 studies: 0.48, 95% CI: 0.23-0.98; and pooled RR from 2 studies: 2.99, 95% CI: 1.60-5.58 respectively). The risk of metachronous advanced neoplasia increased with age (pooled RR from 3 studies: 1.07 per year of age, 95% CI: 1.03-1.11). There was no evidence that any lifestyle risk factors studied were associated with the risk of metachronous CRC or advanced neoplasia.

CONCLUSIONS

The identified risk factors for metachronous CRC and advanced neoplasia might be useful to tailor the existing surveillance guidelines after the first CRC. There were potential limitations due to possible misclassification of the outcome, confounding and risk of bias, and the findings cannot be generalised to high-risk genetic syndrome cases.

Does Chinese herbal medicine (CHM) reduce colorectal adenoma (CRA) recurrence: protocol of a registry-based, cohort study and a qualitative interview

INTRODUCTION

Colorectal adenoma (CRA) is a precancerous lesion for colorectal cancer. Endoscopic resection is the first-line treatment for CRA. However, CRA recurrence rate is high. This proposed study aims to determine if Chinese herbal medicine (CHM) reduces CRA recurrence.

METHODS AND ANALYSIS

This project encompasses an observational, registry-based, cohort study and a nested qualitative study. The cohort study aims to include 364 postpolypectomy CRA participants at Guangdong Provincial Hospital of Chinese Medicine (GPHCM), China, with a follow-up phase of up to 1 year. In addition to routine care, these participants will receive a CHM treatment prescribed by experienced Chinese medicine (CM) clinicians. The CHM treatment encompasses CHM products and CHM formulae according to CM syndromes. The primary outcome is CRA recurrence rate at 1 year after enrolment. Secondary outcomes include characteristics of recurrent CRA, incidence of colorectal polyp (except for CRA), incidence of advanced CRA, incidence of colorectal cancer, improvement of gastrointestinal symptoms commonly seen in CRA patients, faecal occult blood test result, lipid level, fasting plasma glucose level, uric acid level, carcinoembryonic antigen, carbohydrate antigen 19-9, quality of life and safety evaluations. Logistic regression analysis will be used to explore the correlation between exposure and outcome. Qualitative interviews will be conducted among approximate 30 CRA patients from the cohort study and 10 CM practitioners in Department of Gastroenterology at GPHCM. Thematic analysis will be used to analyse qualitative data.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Human Research Ethics Committee (HREC) of GPHCM (YF2022-320-02) and registered at Royal Melbourne Institute of Technology (RMIT) HREC. The results will be disseminated in peer-reviewed journals and international academic conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200065713.

AGA Clinical Practice Update on Risk Stratification for Colorectal Cancer Screening and Post-Polypectomy Surveillance: Expert Review

DESCRIPTION

Since the early 2000s, there has been a rapid decline in colorectal cancer (CRC) mortality, due in large part to screening and removal of precancerous polyps. Despite these improvements, CRC remains the second leading cause of cancer deaths in the United States, with approximately 53,000 deaths projected in 2023. The aim of this American Gastroenterological Association (AGA) Clinical Practice Update Expert Review was to describe how individuals should be risk-stratified for CRC screening and post-polypectomy surveillance and to highlight opportunities for future research to fill gaps in the existing literature.

METHODS

This Expert Review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee (CPUC) 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 CPUC and external peer review through standard procedures of Gastroenterology. These Best Practice Advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these Best Practice Advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: All individuals with a first-degree relative (defined as a parent, sibling, or child) who was diagnosed with CRC, particularly before the age of 50 years, should be considered at increased risk for CRC. BEST PRACTICE ADVICE 2: All individuals without a personal history of CRC, inflammatory bowel disease, hereditary CRC syndromes, other CRC predisposing conditions, or a family history of CRC should be considered at average risk for CRC. BEST PRACTICE ADVICE 3: Individuals at average risk for CRC should initiate screening at age 45 years and individuals at increased risk for CRC due to having a first-degree relative with CRC should initiate screening 10 years before the age at diagnosis of the youngest affected relative or age 40 years, whichever is earlier. BEST PRACTICE ADVICE 4: Risk stratification for initiation of CRC screening should be based on an individual's age, a known or suspected predisposing hereditary CRC syndrome, and/or a family history of CRC. BEST PRACTICE ADVICE 5: The decision to continue CRC screening in individuals older than 75 years should be individualized, based on an assessment of risks, benefits, screening history, and comorbidities. BEST PRACTICE ADVICE 6: Screening options for individuals at average risk for CRC should include colonoscopy, fecal immunochemical test, flexible sigmoidoscopy plus fecal immunochemical test, multitarget stool DNA fecal immunochemical test, and computed tomography colonography, based on availability and individual preference. BEST PRACTICE ADVICE 7: Colonoscopy should be the screening strategy used for individuals at increased CRC risk. BEST PRACTICE ADVICE 8: The decision to continue post-polypectomy surveillance for individuals older than 75 years should be individualized, based on an assessment of risks, benefits, and comorbidities. BEST PRACTICE ADVICE 9: Risk-stratification tools for CRC screening and post-polypectomy surveillance that emerge from research should be examined for real-world effectiveness and cost-effectiveness in diverse populations (eg, by race, ethnicity, sex, and other sociodemographic factors associated with disparities in CRC outcomes) before widespread implementation.

Tip-in Versus Conventional Endoscopic Mucosal Resection for Colorectal Neoplasia: A Systematic Review and Meta-analysis

BACKGROUND

Early-stage gastrointestinal neoplasms are frequently treated with conventional endoscopic mucosal resection (C-EMR). However, C-EMR frequently leads to incomplete resection of large colorectal lesions. Tip-in endoscopic mucosal resection (EMR), which was recently introduced for en bloc resection of colorectal neoplasms, minimizes slippage during the procedure.

METHODS

We conducted a systematic review and meta-analysis of published studies that compared Tip-in EMR with conventional EMR. We searched several electronic databases and included studies that reported on the primary outcomes of en bloc resection rate and complete resection rate, as well as secondary outcomes such as procedure time and procedure-related complications (including perforation and delayed bleeding rate). We used a random effects model to calculate odds ratios (ORs) with 95% CIs for dichotomous data and weighted mean differences with 95% CIs for continuous data. We also conducted several sensitivity analyses to assess the robustness of our findings.

RESULTS

A total of 11 studies involving 1244 lesions (684 in the Tip-in EMR group and 560 in C-EMR group) were included in the meta-analysis. Our meta-analysis showed that compared with conventional EMR, Tip-in EMR significantly increased the en bloc resection rate in patients with colorectal neoplasia (OR=3.61; 95% CI, 2.09-6.23; P <0.00001; I2 =0%) and had a higher complete resection rate (OR=2.49; 95% CI, 1.65-3.76; P <0.0001; I2 =0%). However, the procedure time and rates of procedure-related complications did not differ significantly between the 2 groups.

CONCLUSIONS

Tip-in EMR outperformed C-EMR for both the en bloc and complete resection of colorectal lesions with similar rates of procedural complications.