A risk-prediction score about colorectal lesions based on the Chinese population of high-risk participants aged 50-65 years.

OBJECTIVES: The present study aims to develop an effective risk-prediction score (RPS) to improve screening efficiency and contribute to secondary prevention of colorectal cancer (CRC). STUDY DESIGN: Screening for colorectal lesions. METHODS: 14,398 high-risk individuals aged 50-65 years were included. The baseline characteristics of participants with and without colorectal lesions (CL) were compared using a Chi-squared test. The overall population was randomly split into a training set and a test set in the ratio of 80% and 20%. One-factor and multifactor logistic regression analyses were performed in the training set to construct the RPS (scores of 0-9.62). Area under curve (AUC) was calculated as an estimate of predictive performance using the receiver-operating characteristic (ROC) curve in the test set. RESULTS: In the study population, being male, advanced age, current or previous smoking, weekly alcohol consumption, high body mass index (BMI ≥24 kg/m2), and previously detected colonic polyp were associated with higher risk of CL. Compared to the low-risk group (0-2.31 points), the ORs and 95% confidence intervals (CIs) for the moderate-risk group (2.31-3.85 points) and high-risk group (3.85-8.42 points) were 1.58 (1.44, 1.73) and 2.52 (2.30, 2.76), respectively. For every 1-point increase in score, participants had a 27% increased risk of CL (OR:1.27, 95% CI: 1.24, 1.30). For participants with CL predicted by RPS, the area under the working characteristic curve was 0.61 (P < 0.001). CONCLUSION: Our RPS can quickly and efficiently identify multiple lesions of the colorectum. Combining RPS with existing screening strategies facilitates the identification of very high-risk individuals and may help to prevent CRC.

Combined endoscopic mucosal resection and full-thickness resection for large colorectal polyps: a systematic review and meta-analysis.

BACKGROUND AND AIMS: Combined endoscopic mucosal resection (EMR) with endoscopic Full thickness resection (EFTR) is an emerging technique that has been developed to target colorectal polyps larger than 2 cm. We performed a systematic review and meta-analysis to evaluate this technique for the resection of large colorectal lesions. METHODS: We conducted a comprehensive search of multiple electronic databases from inception through August 2023, to identify studies that reported on hybrid FTR. A random-effects model was employed to calculate the overall pooled technical success, macroscopic complete resection, free vertical margins resection rate, adverse events, and recurrence on follow up. RESULTS: A total of 8 Study arms with 244 patients (30% women) were included in the analysis. The pooled technical success rate was 97% (95% CI 88%-100%, I2 = 79.93%). The pooled rate of macroscopic complete resection was achieved in 95% (95% CI 90%-99%, I2 = 49.98) with a free vertical margins resection rate 88% (95% CI, 78%-96%, I2 = 63.32). The overall adverse events rate was 2% (95% CI 0%-5%, I2 = 11.64) and recurrence rate of 6% (95% CI 2%-12%, I2=20.32). CONCLUSION: Combined EMR with EFTR is effective and safe for resecting large, and complex colorectal adenomas, offering a good alternative for high surgical risk patients. Regional heterogeneity was observed, indicating that outcomes may be impacted by differences in operator expertise and industry training certification across regions. Comparative studies that directly compare combined EMR with EFTR against alternative methods such as ESD and surgical resection are needed.

The frequency of colorectal lesions in the first-degree relatives of patients with colorectal lesions among PERSIAN Guilan Cohort Study population (PGCS).

BACKGROUND: This study aimed to investigate the frequency of colorectal lesions in the first-degree relatives of patients with colorectal lesions among the Prospective Epidemiological Research Studies in Iran (PERSIAN )Guilan Cohort Study (PGCS) population. METHODS: In this cross-sectional study, 162 first-degree relatives with a history of colorectal lesions were randomly selected from 52 participants in PGCS. All subjects underwent total colonoscopy by a gastroenterologist, and a pathologist evaluated colorectal biopsies. Also, individuals' demographic information, clinical data, and dietary habits were recorded. RESULTS: The mean age of the participants was 56.55 ± 7.04. Of 86 colon polyps, 52 neoplastic and 34 non-neoplastic polyps were observed in 56 patients (34.6%). Individuals with age > 60 years had 3.29-fold increased odds of developing colorectal polyps (OR = 3.29, 95% CI: 1.13-9.56, P = 0.029). The smokers were 2.73 times more susceptible to developing colorectal polyps than non-smokers (OR = 2.73, 95% CI: 1.24-6.02, P = 0.013). Moreover, consumption of vegetables more than three times per day was associated with decreased OR of colorectal polyp development (OR = 0.43, CI: 0.19-0.98, P = 0.045). CONCLUSIONS: Considering the high prevalence of neoplastic colorectal polyps among the first-degree relatives of patients with colorectal lesions, early screening is recommended for individuals with a family history of colorectal lesions.

Assessment of water enema PET/CT: an effective imaging technique for the diagnosis of incidental colorectal 18F-FDG uptake.

BACKGROUND: To validate the feasibility of water enema PET/CT (WE-PET/CT) in incidental colorectal 18F-FDG uptake and improve the accuracy of diagnosing colorectal neoplastic lesions. METHODS: We retrospectively analysed the electronic records of 338 patients undergoing common PET/CT and WE-PET/CT at our hospital. PET/CT results were correlated with colonoscopy pathology and follow-up results. The ROC contrast curve was plotted to evaluate the accuracy of SUVmax on common PET/CT and WE-PET/CT for detecting neoplastic lesions. SUVmax and the median retention indexes (RIs) of cancerous, precancerous, and benign lesions and physiologic uptake were compared. RESULTS: The sensitivity, specificity and accuracy of diagnosing neoplastic lesions with common PET/CT were 84.0%, 78.3% and 80.2%, respectively. The corresponding results with WE-PET/CT were 95.8%, 96.5% and 96.2%. The AUC of SUVmax on WE-PET/CT was significantly higher than that on common PET/CT (0.935 vs. 0.524, p < 0.001). The median SUVmax on WE-PET/CT was significantly higher than that on common PET/CT in cancerous and precancerous lesions, and significantly decreased in benign lesions and physiologic uptake (p < 0.001). The RI was significantly different between cancerous lesions and physiologic uptake, between precancerous lesions and physiologic uptake, between benign lesions and physiologic uptake, and between cancerous and benign lesions (p < 0.05). CONCLUSIONS: WE-PET/CT is a noninvasive, well-tolerated and effective technique for diagnosing incidental colorectal 18F-FDG uptake. It is helpful for a timely colonoscopy and can effectively avoid an unnecessary colonoscopy for incidental colorectal 18F-FDG uptake.

An Analysis of Delayed Bleeding in Cases of Colorectal Endoscopic Submucosal Dissection Due to Types of Direct Oral Anticoagulants in Japan.

BACKGROUND & AIMS: Reported rates of delayed bleeding (DB) after endoscopic resection using direct oral anticoagulants (DOACs) are high and heterogeneous. This large-scale multicenter study analyzed cases of DB after colorectal endoscopic submucosal dissection related to various types of DOACs in Japan (the ABCD-J study) with those associated with warfarin. METHODS: We retrospectively reviewed 1019 lesions in patients treated with DOACs and 459 lesions in patients treated with warfarin among 34,455 endoscopic submucosal dissection cases from 47 Japanese institutions between 2012 and 2021. The DB rate (DBR) with each DOAC was compared with that with warfarin. Risk factors for DB in patients treated with DOACs or warfarin were also investigated. RESULTS: The mean tumor sizes in the DOAC and warfarin groups were 29.6 ± 14.0 and 30.3 ± 16.4 mm, respectively. In the DOAC group, the DBR with dabigatran (18.26%) was significantly higher than that with apixaban (10.08%, P = .029), edoxaban (7.73%, P = .001), and rivaroxaban (7.21%, P < .001). Only rivaroxaban showed a significantly lower DBR than warfarin (11.76%, P = .033). In the multivariate analysis, heparin bridging therapy (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.27-3.73, P = .005), rectal location (2.01, 1.28-3.16, P = .002), and procedure time ≥55 minutes (2.43, 1.49-3.95, P < .001) were significant risk factors for DB in the DOAC group. The DB risk in the DOAC group (OR, (95% CI)) was 2.13 (1.30-3.50) and 4.53 (2.52-8.15) for 1 and 2 significant risk factors, respectively. CONCLUSIONS: Dabigatran was associated with a higher DBR than other DOACs, and only rivaroxaban was associated with a significantly lower DBR than warfarin.

Risk of Residual Neoplasia after a Local-Risk Resection of Colorectal Lesions by Endoscopic Submucosal Dissection: A Multinational Study.

Endoscopic submucosal dissection (ESD) in colorectal lesions is demanding, and a significant rate of non-curative procedures is expected. We aimed to assess the rate of residual lesion after a piecemeal ESD resection, or after an en bloc resection but with positive horizontal margins (local-risk resection-LocRR), for colorectal benign neoplasia. A retrospective multicenter analysis of consecutive colorectal ESDs was performed. Patients with LocRR ESDs for the treatment of benign colorectal lesions with at least one follow-up endoscopy were included. A cohort of en bloc resected lesions, with negative margins, was used as the control. A total of 2255 colorectal ESDs were reviewed; 352 of the ESDs were "non-curative". Among them, 209 were LocRR: 133 high-grade dysplasia and 76 low-grade dysplasia. Ten cases were excluded due to missing data. A total of 146 consecutive curative resections were retrieved for comparison. Compared to the "curative group", LocRRs were observed in lengthier procedures, with larger lesions, and in non-granular LSTs. Recurrence was higher in the LocRR group (16/199, 8% vs. 1/146, 0.7%; p = 0.002). However, statistical significance was lost when considering only en bloc resections with positive horizontal margins (p = 0.068). In conclusion, a higher rate of residual lesion was found after a piecemeal ESD resection, but not after an en bloc resection with positive horizontal margins.

Systematic review and meta-analysis of cold snare polypectomy and hot snare polypectomy for colorectal polyps.

BACKGROUND AND AIM: Cold snare polypectomy (CSP) has become increasingly utilized to resect colorectal polyps, given its efficacy and safety. This study aims to compare CSP and hot snare polypectomy (HSP) for resecting small (< 10 mm) and large (10-20 mm) colorectal lesions. METHODS: Relevant publications were obtained from Cochrane Library, Embase, Google Scholar, PubMed, and Web of Science databases. The publication search was limited by English-language and human studies. Pooled mean difference and odds ratios (ORs) were calculated for outcomes of interest. RESULTS: Twenty-three studies were included in this meta-analysis. Pooled OR of delayed post-polypectomy bleeding (DPPB) in the CSP group versus the HSP group was 0.29 (P = 0.0001, I2  = 29%). Subgroup analysis according to lesion size showed a significant reduction in the DPPB rate in lesion sizes 10-20 mm (pooled OR 0.08, P = 0.003, I2  = 0%) and < 10 mm (pooled OR 0.35, P = 0.001, I2  = 27%). Pooled OR of major bleeding in the CSP group was 0.23 (P = 0.0004, I2  = 0%). Subgroup analysis by lesion size revealed a significant decrease in the rate of major bleeding in the CSP group for both lesion sizes 10-20 mm (pooled OR 0.11, P = 0.04) and < 10 mm (pooled OR 0.26, P = 0.003). Complete resection, en bloc resection, and recurrence rate were comparable in the two groups. CONCLUSIONS: Cold snare polypectomy was associated with a lower rate of DPPB and lower risk of major bleeding compared with HSP in both small and large polyps. CSP should be considered as the polypectomy technique of choice for colorectal polyps.

Associations of the 2018 World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) cancer prevention recommendations with stages of colorectal carcinogenesis.

BACKGROUND: While adherence to cancer prevention recommendations is linked to lower risk of colorectal cancer (CRC), few have studied associations across the entire spectrum of colorectal carcinogenesis. Here, we studied the relationship of the standardized 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Score for cancer prevention recommendations with detection of colorectal lesions in a screening setting. As a secondary objective, we examined to what extent the recommendations were being followed in an external cohort of CRC patients. METHODS: Adherence to the seven-point 2018 WCRF/AICR Score was measured in screening participants receiving a positive fecal immunochemical test and in CRC patients participating in an intervention study. Dietary intake, body fatness and physical activity were assessed using self-administered questionnaires. Multinomial logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for screen-detected lesions. RESULTS: Of 1486 screening participants, 548 were free from adenomas, 524 had non-advanced adenomas, 349 had advanced lesions and 65 had CRC. Adherence to the 2018 WCRF/AICR Score was inversely associated with advanced lesions; OR 0.82 (95% CI 0.71, 0.94) per score point, but not with CRC. Of the seven individual components included in the score, alcohol, and BMI seemed to be the most influential. Of the 430 CRC patients included in the external cohort, the greatest potential for lifestyle improvement was seen for the recommendations concerning alcohol and red and processed meat, where 10% and 2% fully adhered, respectively. CONCLUSIONS: Adherence to the 2018 WCRF/AICR Score was associated with lower probability of screen-detected advanced precancerous lesions, but not CRC. Although some components of the score seemed to be more influential than others (i.e., alcohol and BMI), taking a holistic approach to cancer prevention is likely the best way to prevent the occurrence of precancerous colorectal lesions.

Standard Endoscopic Mucosal Resection vs Precutting Endoscopic Mucosal Resection Using Novel Disk-Tip Snare for Colorectal Lesions.

INTRODUCTION: SOUTEN (KANEKA Co., Tokyo, Japan) is a unique snare with a disk tip. We analyzed the efficacy of precutting endoscopic mucosal resection with SOUTEN (PEMR-S) for colorectal lesions. METHODS: We retrospectively reviewed 57 lesions of 10-30 mm treated with PEMR-S at our institution from 2017 to 2022. The indications were lesions that were difficult for standard EMR due to size, morphology, and poor elevation by injection. Various therapeutic results of PEMR-S such as en bloc resection, procedure time, and perioperative hemorrhage were analyzed, and the results of 20 lesions of 20-30 mm with PEMR-S were compared to those of lesions with standard EMR (2012-2014) using propensity score matching. Additionally, the stability of the SOUTEN disk tip was analyzed in a laboratory experiment. RESULTS: The polyp size was 16.5 ± 4.2 mm and the non-polypoid morphology rate was 80.7%. Histopathological diagnosis included 10 sessile-serrated lesions, 43 low-grade and high-grade dysplasias, and 4 T1 cancers. After matching, the en bloc resection and histopathological complete resection rates of lesions of 20-30 mm between PEMR-S and standard EMR (90.0% vs. 58.1%, p = 0.03 and 70.0% vs. 45.0%, p = 0.11). The procedure time (min) was 14.8 ± 9.7 and 9.7 ± 8.3 (p < 0.01). The en bloc resection (%) and procedure time of expert/non-expert were 89.7/85.7 (p = 0.96) and 6.1 ± 2.2/18.5 ± 7.2 (p < 0.01). The perioperative bleeding and hemostasis success rates with SOUTEN were 43.9% and 96.0%. In the experiment, the SOUTEN disk tip was fixed stably compared to other EMR snares. CONCLUSIONS: PEMR-S achieved high en bloc resection of colorectal lesions of 20-30 mm though it leaded to long procedure time.

From advanced diagnosis to advanced resection in early neoplastic colorectal lesions: Never-ending and trending topics in the 2020s.

Colonoscopy represents the most widespread and effective tool for the prevention and treatment of early stage preneoplastic and neoplastic lesions in the panorama of cancer screening. In the world there are different approaches to the topic of colorectal cancer prevention and screening: different starting ages (45-50 years); different initial screening tools such as fecal occult blood with immunohistochemical or immune-enzymatic tests; recto-sigmoidoscopy; and colonoscopy. The key aspects of this scenario are composed of a proper bowel preparation that ensures a valid diagnostic examination, experienced endoscopist in detection of preneoplastic and early neoplastic lesions and open-minded to upcoming artificial intelligence-aided examination, knowledge in the field of resection of these lesions (from cold-snaring, through endoscopic mucosal resection and endoscopic submucosal dissection, up to advanced tools), and management of complications.

Associations of red and processed meat intake with screen-detected colorectal lesions.

Limited data exist regarding the role of meat consumption in early-stage colorectal carcinogenesis. We examined associations of red and processed meat intake with screen-detected colorectal lesions in immunochemical fecal occult blood test (FIT)-positive participants, enrolled in the Norwegian CRCbiome study during 2017-2021, aged 55-77 years. Absolute and energy-adjusted intakes of red and processed meat (combined and individually) were assessed using a validated, semi-quantitative FFQ. Associations between meat intake and screen-detected colorectal lesions were examined using multinomial logistic regression analyses with adjustment for key covariates. Of 1162 participants, 319 presented with advanced colorectal lesions at colonoscopy. High v. low energy-adjusted intakes of red and processed meat combined, as well as red meat alone, were borderline to significantly positively associated with advanced colorectal lesions (OR of 1·24 (95 % CI 0·98, 1·57) and 1·34 (95 % CI 1·07, 1·69), respectively). A significant dose-response relationship was also observed for absolute intake levels (OR of 1·32 (95 % CI 1·09, 1·60) per 100 g/d increase in red and processed meat). For processed meat, no association was observed between energy-adjusted intakes and advanced colorectal lesions. A significant positive association was, however, observed for participants with absolute intake levels ≥ 100 v. < 50 g/d (OR of 1·19 (95 % CI 1·09, 1·31)). In summary, high intakes of red and processed meat were associated with presence of advanced colorectal lesions at colonoscopy in FIT-positive participants. The study demonstrates a potential role of dietary data to improve the performance of FIT-based screening.

Detection of colorectal lesions during colonoscopy.

Owing to its high mortality rate, the prevention of colorectal cancer is of particular importance. The resection of colorectal polyps is reported to drastically reduce colorectal cancer mortality, and examination by endoscopists who had a high adenoma detection rate was found to lower the risk of colorectal cancer, highlighting the importance of identifying lesions. Various devices, imaging techniques, and diagnostic tools aimed at reducing the rate of missed lesions have therefore been developed to improve detection. The distal attachments and devices for improving the endoscopic view angle are intended to help avoid missing blind spots such as folds and flexures in the colon, whereas the imaging techniques represented by image-enhanced endoscopy contribute to improving lesion visibility. Recent advances in artificial intelligence-supported detection systems are expected to supplement an endoscopist's eye through the instant diagnosis of the lesions displayed on the monitor. In this review, we provide an outline of each tool and assess its impact on the reduction in the incidence of missed colorectal polyps by summarizing previous clinical research and meta-analyses. Although useful, the many devices, image-enhanced endoscopy, and artificial intelligence tools exhibited various limitations. Integrating these tools can improve their shortcomings. Combining artificial intelligence-based diagnoses with wide-angle image-enhanced endoscopy may be particularly useful. Thus, we hope that such tools will be available in the near future.

Prevention of late complications of endoscopic resection of colorectal lesions with a coverage agent: Current status of gastrointestinal endoscopy.

Endoscopic ectomy of large nonpedunculated colorectal lesions (≥ 20 mm) might cause significant adverse incidents, such as delayed perforation and delayed bleeding, despite the closure of mucosal lesions with clips. The conventional utilization of prophylactic clipping has not decreased the risk of postprocedural delayed adverse events, and additional outcomes and cost-effectiveness research is needed for patients with proximal lesions ≥ 20 mm, in whom prophylactic clipping might be useful. Coverage of the wound after endoscopic excision offers shield protection against delayed concomitant diseases.

Deep learning driven colorectal lesion detection in gastrointestinal endoscopic and pathological imaging.

Colorectal cancer has the second highest incidence of malignant tumors and is the fourth leading cause of cancer deaths in China. Early diagnosis and treatment of colorectal cancer will lead to an improvement in the 5-year survival rate, which will reduce medical costs. The current diagnostic methods for early colorectal cancer include excreta, blood, endoscopy, and computer-aided endoscopy. In this paper, research on image analysis and prediction of colorectal cancer lesions based on deep learning is reviewed with the goal of providing a reference for the early diagnosis of colorectal cancer lesions by combining computer technology, 3D modeling, 5G remote technology, endoscopic robot technology, and surgical navigation technology. The findings will supplement the research and provide insights to improve the cure rate and reduce the mortality of colorectal cancer.

Colorectal Endoscopic Submucosal Dissection in a Western Center: Analysis of Outcomes and Safety Profile.

INTRODUCTION: Endoscopic submucosal dissection (ESD) is a well-established endoscopic technique for the treatment of gastrointestinal lesions. Colorectal ESD outcomes are less reported in the Western literature, and Portuguese data are still very scarce. Our aim was to describe our experience on colorectal ESD regarding its outcomes and safety profile. METHODS: We conducted a retrospective evaluation of recorded data on ESDs performed between 2015 and 2020. Only ESDs performed on epithelial neoplastic lesions were selected for further analysis. RESULTS: Of a total of 167 colorectal ESDs, 153 were included. Technical success was achieved in 147 procedures (96%). The lesions were located in the colon (n = 24) and rectum (n = 123). The en bloc resection rate was 92% and 97%, the R0 resection rate was 83% and 82%, and the curative resection rate was 79% and 78% for the colon and the rectum, respectively. The need for a hybrid technique was the only risk factor for piecemeal or R1 resection. We report a perforation rate of 3.4% and a 4.1% rate of delayed bleeding; all the adverse events were manageable endoscopically, without the need of blood transfusions or surgery. Most of the lesions were laterally spreading tumours of the granular mixed type (70%), and 20% of the lesions were malignant (12% submucosal and 8% intramucosal cancer). CONCLUSION: Our series on colorectal ESD reports a very good efficacy and safety profile. This technique can be applied by endoscopists experienced in ESD.

INTRODUÇÃO: A dissecção endoscópica da submucosa é uma técnica com comprovada eficácia para o tratamento das lesões do tracto digestivo. As disseções endoscópicas da submucosa de lesões do colon ou recto são menos reportadas na literatura ocidental, e dados Portugueses publicados são escassos. O nosso objectivo foi reportar a eficácia e o perfil de segurança da nossa série nestas lesões. MÉTODOS: Avaliação retrospetiva das dissecções realizadas entre 2015 e 2020, relativamente a lesões epiteliais neoplásicas do colon e recto. RESULTADOS: De um total de 167 lesões colo-rectais, foram incluidas 153. O sucesso técnico foi de 96% (n = 147). As lesões estavam localizadas no colon (n = 24) e recto (n = 123). A taxa de resseção em bloco foi de 92% e 97%, de resseções R0 de 83% e 82% e de resseções curativas foi de 79% e 78% no colon e recto respectivamente. A necessidade de realização de técnica híbrida foi o único factor de risco identificado para ressecção em piecemeal ou R1. Obtivemos uma taxa de perfurado de 3.4% e 4.1% de hemorragia tardia; todos os eventos adversos foram tratados endoscopicamente, sem necessidade de transfusões sanguíneas ou cirurgia. A maioria das lesões eram lateral spreading tumours do tipo granular nodular misto (70%), e 20% das lesões eram malignas (12% com invasão submucosa, 8% carcinomas intramucosos). CONCLUSÃO: A nossa série de dissecções do colon e recto demonstrou uma muito boa eficácia e excelente perfil de segurança. Este procedimento terapêutico pode ser utilização por endoscopistas com experiência nesta técnica.

Detection Accuracy and Latency of Colorectal Lesions with Computer-Aided Detection System Based on Low-Bias Evaluation.

We developed a computer-aided detection (CADe) system to detect and localize colorectal lesions by modifying You-Only-Look-Once version 3 (YOLO v3) and evaluated its performance in two different settings. The test dataset was obtained from 20 randomly selected patients who underwent endoscopic resection for 69 colorectal lesions at the Jikei University Hospital between June 2017 and February 2018. First, we evaluated the diagnostic performances using still images randomly and automatically extracted from video recordings of the entire endoscopic procedure at intervals of 5 s, without eliminating poor quality images. Second, the latency of lesion detection by the CADe system from the initial appearance of lesions was investigated by reviewing the videos. A total of 6531 images, including 662 images with a lesion, were studied in the image-based analysis. The AUC, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.983, 94.6%, 95.2%, 68.8%, 99.4%, and 95.1%, respectively. The median time for detecting colorectal lesions measured in the lesion-based analysis was 0.67 s. In conclusion, we proved that the originally developed CADe system based on YOLO v3 could accurately and instantaneously detect colorectal lesions using the test dataset obtained from videos, mitigating operator selection biases.

Prevention of late complications with coverage agents in endoscopic resection of colorectal lesions: Current landscape in gastrointestinal endoscopy.

Endoscopic removal of large (≥ 20 mm) non-pedunculated colorectal lesions (LNPCLs) may result in major adverse events, such as delayed bleeding (DB) and delayed perforation (DP), despite closure of the mucosal defects with clips. Topical application of a coverage agent refers to the creation of a shield with a biocompatible medical device (tissue or hydrogel) with proven bioactive properties. Coverage of the eschar after endoscopic resection provides shielding protection to prevent delayed complications. The aim of the present review was to systematically collect and review the currently available literature regarding the prevention of DB and DP with coverage agents after endoscopic mucosal resection or endoscopic submucosal dissection of LNPCLs.

Effects of Somatic Methylation in Colonic Polyps on Risk of Developing Metachronous Advanced Colorectal Lesions.

The utility of molecular markers for predicting the risk of metachronous advanced colorectal lesions (MACLs) remains poorly investigated. We examined the relationship between somatic hypermethylation in polyps at baseline and the risk of developing MACL. This retrospective cohort study included 281 consecutive patients with colonic polyps who were enrolled between 2007 and 2009 and followed-up until 2014. MACLs were defined as adenomas of ≥10 mm, high-grade dysplasia, or with a villous component; and serrated lesions of ≥10 mm or with dysplasia. In total, 595 polyps were removed at baseline colonoscopy and analyzed for pathological characteristics and CpG island methylator phenotype (CIMP) using the MS-MLPA (Methylation-Specific -- Multiplex Ligation-dependent Probe Amplification) technique. Forty-five patients (16.0%) showed at least one CIMP+ polyp. MACL risk was higher in patients with CIMP+ polyps (odds ratio (OR), 4.50; 95% CI, 1.78-11.4; p = 0.002). Patients with CIMP+ polyps also exhibited shorter time to MACL development (33.8 months vs. 50.1 months; p < 0.001), even with adjustment for polyp size and number (OR, 2.40; 95% CI, 1.33-4.34). Adding CIMP analysis improved the sensitivity (57.0% to 70.9%), negative predictive value (71.1% to 77.3%), and overall accuracy (49.8% to 52.0%) for MACL risk estimation. These results highlight that CIMP may be a useful marker for endoscopic surveillance.

Colorectal Serrated Lesions: A Current View on Clinical, Morphological, Molecular, and Genetic Diagnostic Criteria.

OBJECTIVE: Serrated colorectal lesions are a group of colonic lesions with a serrated (saw-tooth) profile of the surface epithelium and crypts, and peculiar molecular and genetic developmental mechanisms that are incompletely understood. These formations cause concern due to their premalignant potential. AIM: The review is dedicated to serrated lesions of colon and appendix. We focused on modern classification, role in carcinogenesis, as well as new approaches to morphological diagnosis. METHODS: A literature search was performed using PubMed, Scopus, ResearchGate, Google, MEDLINE, and ScienceDirect databases to find studies of serrated colorectal lesions related cancer published between 2000 and 2020 that address epidemiological risk factors, underlying pathophysiological mechanism and enable our review of these factors as well as molecular, genetics, and structural patterns. RESULTS: Serrated colorectal lesions take one third of all benign neoplasms of the colon in the pathologist's practice. The active study of serrated lesions began in the 1900s. Terminology and diagnostic criteria changed in the updated classification in 2019. Morphological criteria, immunohistochemical and molecular profile, endoscopic and clinical characteristics are reviewed. CONCLUSION: Although significant efforts were made in attempt to improve our understanding and diagnostic criteria of serrated polyps of colorectum, very little has changed since the original morphologic description of preneoplastic serrated lesions in early 2000s. There remains a need for more research in order to develop more definitive immuophenotypic and molecular biomarkers in order to distinguish between non-neoplastic and neoplastic serrated lesions.

Underwater endoscopic mucosal resection for colorectal lesions: a meta-analysis.

BACKGROUND: Underwater endoscopic mucosal resection (UEMR) of colorectal lesions is emerging as an alternative method to conventional endoscopic mucosal resection (CEMR). This study aimed to evaluate the feasibility and safety of UEMR for colorectal lesions. METHODS: The PubMed, Embase, Cochrane and Web of Science databases were searched before May 10, 2020. The primary outcomes were en bloc resection rate (feasibility) and adverse event rate (safety). The secondary outcome was recurrence and residual adenoma rate. If there was a comparison between UEMR and CEMR, data about en bloc resection, delayed bleeding, and recurrence and residual adenoma were extracted and compared. The pooling of the effect size was conducted using random-effects models, and the Q-statistic, τ2, and I2 were used to evaluate heterogeneity. RESULTS: Seventeen studies (759 patients, 893 lesions) were included. The pooled estimate for the en bloc resection rate was 59% (95% CI 43-75%) with significant heterogeneity (I2 = 97%). Due to the heterogeneity, it is not suitable to conduct pooled estimates analysis, so the en bloc resection rate was from 10 to 89%. The pooled estimate for delayed bleeding was 2% (95% CI, 1%-3%) and only two cases had perforation. The pooled rate of recurrence and residual adenoma was 5% (95% CI 2%-8%). Compared with CEMR, UEMR could achieve a higher en bloc resection rate (OR 1.61; 95% CI 1.02-2.53; p = 0.04) with a lower rate of recurrence and residual adenoma (OR 0.18; 95% CI 0.07-0.46; p < 0.01). CONCLUSIONS: UEMR for colorectal lesions was capable of a high en bloc resection rate, low adverse event rate and low recurrence. UEMR may be considered an effective and safe alternative for treating colorectal lesions.