Artificial Intelligence for Real-Time Prediction of the Histology of Colorectal Polyps by General Endoscopists.

BACKGROUND: Real-time prediction of histologic features of small colorectal polyps may prevent resection and/or pathologic evaluation and therefore decrease colonoscopy costs. Previous studies showed that computer-aided diagnosis (CADx) was highly accurate, though it did not outperform expert endoscopists. OBJECTIVE: To assess the diagnostic performance of histologic predictions by general endoscopists before and after assistance from CADx in a real-life setting. DESIGN: Prospective, multicenter, single-group study. (ClinicalTrials.gov: NCT04437615). SETTING: 6 centers across the United States. PARTICIPANTS: 1252 consecutive patients undergoing colonoscopy and 49 general endoscopists with variable experience in real-time prediction of polyp histologic features. INTERVENTION: Real-time use of CADx during routine colonoscopy. MEASUREMENTS: The primary end points were the sensitivity and specificity of CADx-unassisted and CADx-assisted histologic predictions for adenomas measuring 5 mm or less. For clinical purposes, additional estimates according to location and confidence level were provided. RESULTS: The CADx device made a diagnosis for 2695 polyps measuring 5 mm or less (96%) in 1252 patients. There was no difference in sensitivity between the unassisted and assisted groups (90.7% vs. 90.8%; P = 0.52). Specificity was higher in the CADx-assisted group (59.5% vs. 64.7%; P < 0.001). Among all 2695 polyps measuring 5 mm or less, 88.2% and 86.1% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be resected and discarded without pathologic evaluation. Among 743 rectosigmoid polyps measuring 5 mm or less, 49.5% and 47.9% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be left in situ without resection. LIMITATION: Decision making based on CADx might differ outside a clinical trial. CONCLUSION: CADx assistance did not result in increased sensitivity of optical diagnosis. Despite a slight increase, the specificity of CADx-assisted diagnosis remained suboptimal. PRIMARY FUNDING SOURCE: Olympus America Corporation served as the clinical study sponsor.

Computer-Aided Diagnosis for Leaving Colorectal Polyps In Situ : A Systematic Review and Meta-analysis.

BACKGROUND: Computer-aided diagnosis (CADx) allows prediction of polyp histology during colonoscopy, which may reduce unnecessary removal of nonneoplastic polyps. However, the potential benefits and harms of CADx are still unclear. PURPOSE: To quantify the benefit and harm of using CADx in colonoscopy for the optical diagnosis of small (≤5-mm) rectosigmoid polyps. DATA SOURCES: Medline, Embase, and Scopus were searched for articles published before 22 December 2023. STUDY SELECTION: Histologically verified diagnostic accuracy studies that evaluated the real-time performance of physicians in predicting neoplastic change of small rectosigmoid polyps without or with CADx assistance during colonoscopy. DATA EXTRACTION: The clinical benefit and harm were estimated on the basis of accuracy values of the endoscopist before and after CADx assistance. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework. The outcome measure for benefit was the proportion of polyps predicted to be nonneoplastic that would avoid removal with the use of CADx. The outcome measure for harm was the proportion of neoplastic polyps that would be not resected and left in situ due to an incorrect diagnosis with the use of CADx. Histology served as the reference standard for both outcomes. DATA SYNTHESIS: Ten studies, including 3620 patients with 4103 small rectosigmoid polyps, were analyzed. The studies that assessed the performance of CADx alone (9 studies; 3237 polyps) showed a sensitivity of 87.3% (95% CI, 79.2% to 92.5%) and specificity of 88.9% (CI, 81.7% to 93.5%) in predicting neoplastic change. In the studies that compared histology prediction performance before versus after CADx assistance (4 studies; 2503 polyps), there was no difference in the proportion of polyps predicted to be nonneoplastic that would avoid removal (55.4% vs. 58.4%; risk ratio [RR], 1.06 [CI, 0.96 to 1.17]; moderate-certainty evidence) or in the proportion of neoplastic polyps that would be erroneously left in situ (8.2% vs. 7.5%; RR, 0.95 [CI, 0.69 to 1.33]; moderate-certainty evidence). LIMITATION: The application of optical diagnosis was only simulated, potentially altering the decision-making process of the operator. CONCLUSION: Computer-aided diagnosis provided no incremental benefit or harm in the management of small rectosigmoid polyps during colonoscopy. PRIMARY FUNDING SOURCE: European Commission. (PROSPERO: CRD42023402197).

Technical failure during Colorectal Endoscopic Full Thickness Resection: The "through thick and thin" Study.

BACKGROUND: Endoscopic full-thickness resection (EFTR) is an effective and safe technique for non-lifting colorectal lesions. Technical issues or failures with full-thickness resection device (FTRD) system are reported but there are no data about their details. The aim of our study was to quantify and classify FTRD technical failures. PATIENTS AND METHODS: We performed a retrospective study involving 17 Italian centres with experience in advanced resection techniques and OVESCO devices. Each centre shared and classified all the consecutive failures prospectively collected during colorectal EFTR by using FTRD from 2018 to 2022. Primary outcome was technical failure rate and classification; secondary outcomes included management, clinical success, and complications' assessment in this population. RESULTS: Included lesions were mainly recurrent (52%), with mean dimension of 18.4 (± 7.5) mm. Among 750 EFTRs, failures occurred in 77 patients (35 F, mean age 68.9 ±8.9 years). A classification was proposed in type I snare uncutting (53.2%), type II clip misdeployment (31.2%) and type III cap misplacement (15.6%). Among endoscopic treatment completed, rescue EMR was performed in 57 patients (79%), allowing en-bloc and R0 resection in 71% and 64% cases, respectively. Overall adverse events rate was 27.3%. Pooled estimates for the rate of failure, complications and rescue endoscopic therapy were similar between low- and high-volume centres (p=0.08, p = 0.702 and p= 0.713). CONCLUSIONS: Colorectal EFTR with FTRD is a challenging technique with a not negligible rate of technical failure and complications. Experience in rescue resection techniques and multidisciplinary management are mandatory in this setting.

Management of perforations during endoscopic resection.

Despite the evolution in tools and techniques, perforation is still one of the most pernicious adverse events of therapeutic endoscopy with potentially huge consequences. As advanced endoscopic resection techniques are worldwide spreading, endoscopists must be ready to manage intraprocedural perforations. In fact, immediate endoscopic closure through a prompt diagnosis represents the first-line option, saving patients from surgery, long hospitalizations and worse outcomes. Traditional and novel endoscopic closure modalities, including clips, suturing devices, stents and vacuum therapy, are increasingly expanding the therapeutic armamentarium for closing these defects. Nevertheless, available literature on this topic is currently limited. In this review our goal is to give an overview on the management of perforations occurring during endoscopic resections, with particular attention to characteristics, advantages, disadvantages and new horizons of endoscopic closure tools.

Establishing the optimal number of passes during EUS-FNB for diagnosis of pancreatic solid lesions: Prospective multicenter study.

Background and study aims The optimal number of needle passes during endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is not yet established. We aimed to perform a per-pass analysis of the diagnostic accuracy of EUS-FNB of solid pancreatic lesions using a 22G Franseen needle. Patients and methods Consecutive patients with solid pancreatic lesions referred to 11 Italian centers were prospectively enrolled. Three needle passes were performed; specimens were collected after each pass and processed individually as standard histology following macroscopic on-site evaluation (MOSE) by the endoscopist. The primary endpoint was diagnostic accuracy of each sequential pass. Final diagnosis was established based on surgical pathology or a clinical course of at least 6 months. Secondary endpoints were specimen adequacy, MOSE reliability, factors impacting diagnostic accuracy, and procedure-related adverse events. Results A total of 504 samples from 168 patients were evaluated. Diagnostic accuracy was 90.5% (85.0%-94.1%) after one pass and 97.6% (94.1%-99.3%) after two passes ( P =0.01). Similarly, diagnostic sensitivity and sample adequacy were significantly higher adding the second needle pass (90.2%, 84.6%-94.3% vs 97.5%, 93.8%-99.3%, P =0.009 and 91.1%, 85.7%-94.9% vs 98.2%, 95.8%-99.3%, P =0.009, one pass vs two passes, respectively). Accuracy, sensitivity, and adequacy remained the same after the third pass. The concordance between MOSE and histological evaluation was 89.9%. The number of passes was the only factor associated with accuracy. One case of mild acute pancreatitis (0.6%) was managed conservatively. Conclusions At least two passes should be performed for the diagnosis of solid pancreatic lesions. MOSE is a reliable tool to predict the histological adequacy of specimens.

Consensus statements on the current landscape of artificial intelligence applications in endoscopy, addressing roadblocks, and advancing artificial intelligence in gastroenterology.

BACKGROUND AND AIMS: The American Society for Gastrointestinal Endoscopy (ASGE) AI Task Force along with experts in endoscopy, technology space, regulatory authorities, and other medical subspecialties initiated a consensus process that analyzed the current literature, highlighted potential areas, and outlined the necessary research in artificial intelligence (AI) to allow a clearer understanding of AI as it pertains to endoscopy currently. METHODS: A modified Delphi process was used to develop these consensus statements. RESULTS: Statement 1: Current advances in AI allow for the development of AI-based algorithms that can be applied to endoscopy to augment endoscopist performance in detection and characterization of endoscopic lesions. Statement 2: Computer vision-based algorithms provide opportunities to redefine quality metrics in endoscopy using AI, which can be standardized and can reduce subjectivity in reporting quality metrics. Natural language processing-based algorithms can help with the data abstraction needed for reporting current quality metrics in GI endoscopy effortlessly. Statement 3: AI technologies can support smart endoscopy suites, which may help optimize workflows in the endoscopy suite, including automated documentation. Statement 4: Using AI and machine learning helps in predictive modeling, diagnosis, and prognostication. High-quality data with multidimensionality are needed for risk prediction, prognostication of specific clinical conditions, and their outcomes when using machine learning methods. Statement 5: Big data and cloud-based tools can help advance clinical research in gastroenterology. Multimodal data are key to understanding the maximal extent of the disease state and unlocking treatment options. Statement 6: Understanding how to evaluate AI algorithms in the gastroenterology literature and clinical trials is important for gastroenterologists, trainees, and researchers, and hence education efforts by GI societies are needed. Statement 7: Several challenges regarding integrating AI solutions into the clinical practice of endoscopy exist, including understanding the role of human-AI interaction. Transparency, interpretability, and explainability of AI algorithms play a key role in their clinical adoption in GI endoscopy. Developing appropriate AI governance, data procurement, and tools needed for the AI lifecycle are critical for the successful implementation of AI into clinical practice. Statement 8: For payment of AI in endoscopy, a thorough evaluation of the potential value proposition for AI systems may help guide purchasing decisions in endoscopy. Reliable cost-effectiveness studies to guide reimbursement are needed. Statement 9: Relevant clinical outcomes and performance metrics for AI in gastroenterology are currently not well defined. To improve the quality and interpretability of research in the field, steps need to be taken to define these evidence standards. Statement 10: A balanced view of AI technologies and active collaboration between the medical technology industry, computer scientists, gastroenterologists, and researchers are critical for the meaningful advancement of AI in gastroenterology. CONCLUSIONS: The consensus process led by the ASGE AI Task Force and experts from various disciplines has shed light on the potential of AI in endoscopy and gastroenterology. AI-based algorithms have shown promise in augmenting endoscopist performance, redefining quality metrics, optimizing workflows, and aiding in predictive modeling and diagnosis. However, challenges remain in evaluating AI algorithms, ensuring transparency and interpretability, addressing governance and data procurement, determining payment models, defining relevant clinical outcomes, and fostering collaboration between stakeholders. Addressing these challenges while maintaining a balanced perspective is crucial for the meaningful advancement of AI in gastroenterology.

Over-the-scope clip as first-line treatment of peptic ulcer bleeding: a multicenter randomized controlled trial (TOP Study).

BACKGROUND: First-line over-the-scope (OTS) clip treatment has shown higher efficacy than standard endoscopic therapy in acute nonvariceal upper gastrointestinal bleeding (NVUGIB) from different causes. We compared OTS clips with through-the-scope (TTS) clips as first-line mechanical treatment in the specific setting of peptic ulcer bleeding. METHODS: We conducted an international, multicenter randomized controlled trial on consecutive patients with suspected NVUGIB. Patients with Forrest Ia-IIb gastroduodenal peptic ulcer were randomized 1:1 to OTS clip or TTS clip treatment. The primary outcome was the rate of 30-day rebleeding after successful initial hemostasis. Secondary outcomes included the rates of successful initial hemostasis and overall clinical success, defined as the composite of successful initial hemostasis and no evidence of 30-day rebleeding. RESULTS: 251 patients were screened and 112 patients were randomized to OTS (n = 61) or TTS (n = 51) clip treatment. The 30-day rebleeding rates were 1.6% (1/61) and 3.9% (2/51) in patients treated with OTS clips and TTS clips, respectively (Kaplan-Meier log-rank, P = 0.46). Successful initial hemostasis rates were 98.4% (60/61) in the OTS clip group and 78.4% (40/51) in the TTS clip group (P = 0.001). Overall clinical success rates were 96.7% (59/61) with OTS clips and 74.5% (38/51) with TTS clips (P = 0.001). CONCLUSIONS: Low rates of 30-day rebleeding were observed after first-line endoscopic treatment of acute peptic ulcer bleeding with either OTS or TTS clips. However, OTS clips showed higher efficacy than TTS clips in achieving successful initial hemostasis and overall clinical success.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024.

1: ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2: ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3: ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4: ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5: ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6: ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7: Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8: ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9: ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10: ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11: ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Endoscopic Resection for Duodenal Neuroendocrine Neoplasms between 10 and 20 mm-A Systematic Review and Meta-Analysis.

Background. The optimal management of duodenal neuroendocrine neoplasms (dNENs) sized 10-20 mm remains controversial and although endoscopic resection is increasingly performed instead of surgery, the therapeutic approach in this setting is not fully standardized. We performed a systematic review of the literature and a meta-analysis to clarify the outcomes of endoscopic resection for 10-20 mm dNENs in terms of efficacy (i.e., recurrence rate) and safety. Methods. A computerized literature search was performed using relevant keywords to identify pertinent articles published until January 2023. Results. Seven retrospective studies were included in this systematic review. The overall recurrence rate was 14.6% (95%CI 5.4-27.4) in 65 patients analyzed, without significant heterogeneity. When considering studies specifically focused on endoscopic mucosal resection, the recurrence rate was 20.5% (95%CI 10.7-32.4), without significant heterogeneity. The ability to obtain the free margin after endoscopic resection ranged between 36% and 100%. No complications were observed in the four studies reporting this information. Conclusions. Endoscopic resection could be the first treatment option in patients with dNENs sized 10-20 mm and without evidence of metastatic disease. Further studies are needed to draw more solid conclusions, particularly in terms of superiority among the available endoscopic techniques.

Management of Malignant Gastric Outlet Obstruction: A Comprehensive Review on the Old, the Classic and the Innovative Approaches.

Gastrojejunostomy is the principal method of palliation for unresectable malignant gastric outlet obstructions (GOO). Gastrojejunostomy was traditionally performed as a surgical procedure with an open approach butrecently, notable progress in the development of minimally invasive procedures such as laparoscopic gastrojejunostomies have emerged. Additionally, advancements in endoscopic techniques, including endoscopic stenting (ES) and endoscopic ultrasound-guided gastroenterostomy (EUS-GE), are becoming more prominent. ES involves the placement of self-expandable metal stents (SEMS) to restore luminal patency. ES is commonly the first choice for patients deemed unfit for surgery or at high surgical risk. However, although ES leads to rapid improvement of symptoms, it carries limitations like higher stent dysfunction rates and the need for frequent re-interventions. Recently, EUS-GE has emerged as a potential alternative, combining the minimally invasive nature of the endoscopic approach with the long-lasting effects of a gastrojejunostomy. Having reviewed the advantages and disadvantages of these different techniques, this article aims to provide a comprehensive review regarding the management of unresectable malignant GOO.

Management of Post-Operative Crohn's Disease: Knowns and Unknowns.

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract characterized by relapsing-remission phases. CD often requires surgical intervention during its course, mainly ileo-cecal/ileo-colonic resection. However, surgery in CD is not curative and post-operative recurrence (POR) can happen. The management of CD after surgery presents challenges. Ensuring timely, effective, and safe therapy to prevent POR is essential but difficult, considering that approximately 20-30% of subjects may not experience endoscopic POR and that 40-50% will only exhibit intermediate lesions, which carry a low risk of mid- and long-term clinical and surgical POR. Currently, there are two accepted intervention strategies: early post-operative prophylactic therapy (systematically or based on the patient's risk of recurrence) or starting therapy after confirming endoscopic POR 6-12 months after surgery (endoscopy-driven prophylactic therapy). The risk of overtreatment lies in exposing patients to undesired adverse events, along with the costs associated with medications. Conversely, undertreatment may lead to missed opportunities to prevent bowel damage and the necessity for additional surgery. This article aims to perform a comprehensive review regarding the optimal strategy to reduce the risk of POR in CD patients and the current therapeutic options.

Microbial composition associated with biliary stents in patients undergoing pancreatic resection for cancer.

Malignant bile duct obstruction is typically treated by biliary stenting, which however increases the risk of bacterial infections. Here, we analyzed the microbial content of the biliary stents from 56 patients finding widespread microbial colonization. Seventeen of 36 prevalent stent species are common oral microbiome members, associate with disease conditions when present in the gut, and include dozens of biofilm- and antimicrobial resistance-related genes. This work provides an overview of the microbial communities populating the stents.

Outcomes predictors in endoscopic ultrasound-guided choledochoduodenostomy with lumen-apposing metal stent: Systematic review and meta-analysis.

Background and study aims EUS-guided choledochoduodenostomy (EUS-CDS) is a minimally invasive procedure used to treat malignant biliary obstruction (MBO) by transduodenal placement of a lumen-apposing metal stent (LAMS) into the extrahepatic bile duct. To identify factors that contribute to safe and effective EUS-CDS using LAMS, we performed a systematic review of the literature and meta-analysis. Methods The methodology of our analysis was based on PRISMA recommendations. Electronic databases (Medline, Scopus, EMBASE) were searched up to November 2022. Full articles that included patients with distal malignant biliary obstruction who underwent EUS-CDS using LAMS after failed endoscopic retrograde cholangiopancreatography were eligible. Random-effect meta-analysis was performed reporting pooled rates of technical success, clinical success, and adverse events (AEs) by means of a random model. Multivariate meta-regression and subgroup analysis were performed to assess possible associations between the outcomes and selected variables to assess the correlation between outcomes and different variables. Results were also stratified according to stent size. Results Twelve studies with 845 patients were included in the meta-analysis. Pooled technical and clinical success rates were 96% (95% confidence interval [CI] 94%-98%; I 2 = 52.29%) and 96% (95%CI 95%-98%), respectively, with no significant association with baseline characteristics, such are sex, age, common bile duct diameter, or stent size. The pooled AE rate was 12% (95%CI: 8%-16%; I 2 = 71.62%). The AE rate was significantly lower when using an 8 × 8 mm stent as compared with a 6 × 8 mm LAMS (odds ratio 0.59, 0.35-0.99; P = 0.04), with no evidence of heterogeneity (I 2 = 0%). Conclusions EUS-CDS with LAMS is a safe and effective option for relief of MBO. Selecting an appropriate stent size is crucial for achieving optimal safety outcomes.

Efficacy and safety of endoscopic ultrasound-guided hepatico-gastrostomy: a meta-regression analysis.

BACKGROUND AND STUDY AIM: EUS-guided hepaticogastrostomy (EUS-HGS) is a valid option for EUS-guided biliary drainage that has been increasingly used in the last decade. The aims of the study were to provide a systematic review with meta-analysis and meta-regression of features and outcomes of this procedure. METHODS: MEDLINE, Scopus, Web-of-Science, and Cochrane databases were searched for literature pertinent to EUS-HGS. Meta-analysis of proportions and meta-regression of potential modifiers of the main outcome measures were applied. The main outcome was technical success. Secondary outcomes were clinical success and procedure-related adverse events (AEs). RESULTS: Thirty-three studies including 1644 patients were included in the meta-analysis. Malignant biliary obstruction was the underlying cause in almost all (99.6%) cases; the main indications for EUS-HGS were duodenal/papillary invasion (34.8%), surgical altered anatomy (18.4%) and hilar stenosis (16%). Pooled technical success of EUS-HGS was 97.7% (95%-CI: 96.1-99%, I2=0%), the intention to treat (ITT) clinical success was 88.1% (95%-CI: 84.7-91.2%, I2=33.9%) and procedure-related AEs occurred in 12% (95%-CI: 9.8-14.5%, I2=20.4%), being cholangitis/sepsis (2.8%) and bleeding (2.3%) the most frequent. The rate of procedure related AEs was reduced with the use of dedicated stents at the univariable meta regression analysis. Meta-regression showed that technical success and clinical success rates were modified by centers' experience (>4/year). CONCLUSIONS: EUS-HGS represents an effective and safe procedure for EUS-guided biliary drainage in patients with malignant biliary obstruction. Future studies should address the impact of center experience, patient selection, and use of dedicated stents to improve this technique's performance.

Artificial Intelligence-assisted colonoscopy and colorectal cancer screening: Where are we going?

Colorectal cancer is a significant global health concern, necessitating effective screening strategies to reduce its incidence and mortality rates. Colonoscopy plays a crucial role in the detection and removal of colorectal neoplastic precursors. However, there are limitations and variations in the performance of endoscopists, leading to missed lesions and suboptimal outcomes. The emergence of artificial intelligence (AI) in endoscopy offers promising opportunities to improve the quality and efficacy of screening colonoscopies. In particular, AI applications, including computer-aided detection (CADe) and computer-aided characterization (CADx), have demonstrated the potential to enhance adenoma detection and optical diagnosis accuracy. Additionally, AI-assisted quality control systems aim to standardize the endoscopic examination process. This narrative review provides an overview of AI principles and discusses the current knowledge on AI-assisted endoscopy in the context of screening colonoscopies. It highlights the significant role of AI in improving lesion detection, characterization, and quality assurance during colonoscopy. However, further well-designed studies are needed to validate the clinical impact and cost-effectiveness of AI-assisted colonoscopy before its widespread implementation.

Lynch Syndrome: From Multidisciplinary Management to Precision Prevention.

BACKGROUND AND AIMS: Lynch syndrome (LS) is currently one of the most prevalent hereditary cancer conditions, accounting for 3% of all colorectal cancers and for up to 15% of those with DNA mismatch repair (MMR) deficiency, and it was one of the first historically identified. The understanding of the molecular carcinogenesis of LS tumors has progressed significantly in recent years. We aim to review the most recent advances in LS research and explore genotype-based approaches in surveillance, personalized cancer prevention, and treatment strategies. METHODS: PubMed was searched to identify relevant studies, conducted up to December 2023, investigating molecular carcinogenesis in LS, surveillance strategies, cancer prevention, and treatment in LS tumors. RESULTS: Multigene panel sequencing is becoming the benchmark in the diagnosis of LS, allowing for the detection of a pathogenic constitutional variant in one of the MMR genes. Emerging data from randomized controlled trials suggest possible preventive roles of resistant starch and/or aspirin in LS. Vaccination with immunogenic frameshift peptides appears to be a promising approach for both the treatment and prevention of LS-associated cancers, as evidenced by pre-clinical and preliminary phase 1/2a studies. CONCLUSIONS: Although robust diagnostic algorithms, including prompt testing of tumor tissue for MMR defects and referral for genetic counselling, currently exist for suspected LS in CRC patients, the indications for LS screening in cancer-free individuals still need to be refined and standardized. Investigation into additional genetic and non-genetic factors that may explain residual rates of interval cancers, even in properly screened populations, would allow for more tailored preventive strategies.

Saline-immersion peroral endoscopic septotomy: a case report.

Video 1Saline-immersion peroral endoscopic septotomy.