CT and MRI of Gastrointestinal Stromal Tumors: New Trends and Perspectives.

Gastrointestinal stromal tumors (GISTs) are defined as mesenchymal tumors of the gastrointestinal tract that express positivity for CD117, which is a c-KIT proto-oncogene antigen. Expression of the c-KIT protein, a tyrosine kinase growth factor receptor, allows the distinction between GISTs and other mesenchymal tumors such as leiomyoma, leiomyosarcoma, schwannoma and neurofibroma. GISTs can develop anywhere in the gastrointestinal tract, as well as in the mesentery and omentum. Over the years, the management of GISTs has improved due to a better knowledge of their behaviors and risk or recurrence, the identification of specific mutations and the use of targeted therapies. This has resulted in a better prognosis for patients with GISTs. In parallel, imaging of GISTs has been revolutionized by tremendous progress in the field of detection, characterization, survival prediction and monitoring during therapy. Recently, a particular attention has been given to radiomics for the characterization of GISTs using analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence with the aim of better characterizing GISTs and providing a more precise assessment of tumor burden. This article sums up recent advances in computed tomography and magnetic resonance imaging of GISTs in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning.

CT and MRI of abdominal cancers: current trends and perspectives in the era of radiomics and artificial intelligence.

Abdominal cancers continue to pose daily challenges to clinicians, radiologists and researchers. These challenges are faced at each stage of abdominal cancer management, including early detection, accurate characterization, precise assessment of tumor spread, preoperative planning when surgery is anticipated, prediction of tumor aggressiveness, response to therapy, and detection of recurrence. Technical advances in medical imaging, often in combination with imaging biomarkers, show great promise in addressing such challenges. Information extracted from imaging datasets owing to the application of radiomics can be used to further improve the diagnostic capabilities of imaging. However, the analysis of the huge amount of data provided by these advances is a difficult task in daily practice. Artificial intelligence has the potential to help radiologists in all these challenges. Notably, the applications of AI in the field of abdominal cancers are expanding and now include diverse approaches for cancer detection, diagnosis and classification, genomics and detection of genetic alterations, analysis of tumor microenvironment, identification of predictive biomarkers and follow-up. However, AI currently has some limitations that need further refinement for implementation in the clinical setting. This review article sums up recent advances in imaging of abdominal cancers in the field of image/data acquisition, tumor detection, tumor characterization, prognosis, and treatment response evaluation.

Cinematic Rendering of Gastrointestinal Stromal Tumors: A Review of Current Possibilities and Future Developments.

Gastrointestinal stromal tumors (GISTs) are defined as CD117-positive primary, spindled or epithelioid, mesenchymal tumors of the gastrointestinal tract, omentum, or mesentery. While computed tomography (CT) is the recommended imaging modality for GISTs, overlap in imaging features between GISTs and other gastrointestinal tumors often make radiological diagnosis and subsequent selection of the optimal therapeutic approach challenging. Cinematic rendering is a novel CT post-processing technique that generates highly photorealistic anatomic images based on a unique lighting model. The global lighting model produces high degrees of surface detail and shadowing effects that generate depth in the final three-dimensional display. Early studies have shown that cinematic rendering produces high-quality images with enhanced detail by comparison with other three-dimensional visualization techniques. Cinematic rendering shows promise in improving the visualization of enhancement patterns and internal architecture of abdominal lesions, local tumor extension, and global disease burden, which may be helpful for lesion characterization and pretreatment planning. This article discusses and illustrates the application of cinematic rendering in the evaluation of GISTs and the unique benefit of using cinematic rendering in the workup of GIST with a specific emphasis on tumor characterization and preoperative planning.

A preoperative computed tomography radiomics model to predict disease-free survival in patients with pancreatic neuroendocrine tumors.

IMPORTANCE: Imaging has demonstrated capabilities in the diagnosis of pancreatic neuroendocrine tumors (pNETs), but its utility for prognostic prediction has not been elucidated yet. OBJECTIVE: The aim of this study was to build a radiomics model using preoperative computed tomography (CT) data that may help predict recurrence-free survival (RFS) or OS in patients with pNET. DESIGN: We performed a retrospective observational study in a cohort of French patients with pNETs. PARTICIPANTS: Patients with surgically resected pNET and available CT examinations were included. INTERVENTIONS: Radiomics features of preoperative CT data were extracted using 3D-Slicer® software with manual segmentation. Discriminant features were selected with penalized regression using least absolute shrinkage and selection operator method with training on the tumor Ki67 rate (≤2 or >2). Selected features were used to build a radiomics index ranging from 0 to 1. OUTCOME AND MEASURE: A receiving operator curve was built to select an optimal cutoff value of the radiomics index to predict patient RFS and OS. Recurrence-free survival and OS were assessed using Kaplan-Meier analysis. RESULTS: Thirty-seven patients (median age, 61 years; 20 men) with 37 pNETs (grade 1, 21/37 [57%]; grade 2, 12/37 [32%]; grade 3, 4/37 [11%]) were included. Patients with a radiomics index >0.4 had a shorter median RFS (36 months; range: 1-133) than those with a radiomics index ≤0.4 (84 months; range: 9-148; P = .013). No associations were found between the radiomics index and OS (P = .86).

Beyond atezolizumab plus bevacizumab in patients with advanced hepatocellular carcinoma: overall efficacy and safety of tyrosine kinase inhibitors in a real-world setting.

Background: In patients with advanced hepatocellular carcinoma (HCC) progressing after atezolizumab and bevacizumab, the optimal therapeutic sequence is still unclear and no second-line agent has proven its efficacy. Objectives: The aim of this retrospective multicenter real-world cohort study was to provide an evaluation of the efficacy and safety of the use of second-line tyrosine kinase inhibitors (TKIs) in this population. Methods: All patients with advanced HCC, treated in first-line setting by atezolizumab-bevacizumab, and who received at least one dose of treatment with TKI were included in this study. All the data were retrospectively collected from medical records. The primary outcome was progression-free survival (PFS). Secondary outcomes were overall survival (OS), overall global survival (OGS), and safety. A total of 82 patients were included in this study. Results: Patients were assigned to the regorafenib group (n = 29, 35.4%) or other TKI (sorafenib n = 41, lenvatinib n = 8, or cabozantinib n = 4) group (n = 53). PFS was not significantly different between the two groups [2.6 versus 2.8 months, HR 1.07 (95% CI: 0.61-1.86), p = 0.818]. Median PFS rates were 2.6, 4.4, and 2.8 months in sorafenib-, lenvatinib-, and cabozantinib group, respectively. OS was statistically different between the regorafenib group and other TKI group [15.8 versus 7.0 months, HR 0.40 (95% CI: 0.20-0.79), p = 0.023]. When adjusting on confounding factors, there was still a difference in OS favoring the regorafenib group (adjusted hazard ratio 0.35, p = 0.019). OGS of patients who received regorafenib was improved compared to other TKI [18.6 versus 15.0 months, HR 0.42 (95% CI: 0.22-0.84), p = 0.036]. Twenty percent of patients had grade 3 and none had grade 4 or 5 adverse events. In patients who experienced disease progression and fit for a third-line treatment, 80% and 50% received cabozantinib in regorafenib group and other TKI group, respectively. Conclusion: Efficacy of any TKI in the second-line setting was not affected by atezolizumab-bevacizumab treatment as first-line therapy. The safety profile in the second-line setting was consistent with the results shown in pivotal studies. PFS rates of patients were similar, regardless of TKI type. Regorafenib was associated with better OS and OGS rates compared to other TKI. These data need to be confirmed in prospective comparative studies.

Diagnostic Yield of Repeat Endoscopic Ultrasound-Guided Fine Needle Biopsy for Solid Pancreatic Lesions.

PATIENTS AND METHODS: we performed a retrospective case-control study, including cases with repeat EUS FNB for a solid pancreatic lesion, matched on a 1:2 ratio on age, sex, tumor location and presence of chronic pancreatitis with cases diagnosed on the first EUS FNB. RESULTS: thirty-four cases and 68 controls were included in the analysis. Diagnostic accuracies were 80% and 88% in the repeat and single EUS FNB groups, respectively (p = 0.824). The second EUS FNB had a sensitivity of 80%, a specificity of 75%, a positive predictive value of 96%, and a negative predictive value of 33%. Of the 34 patients in the repeat EUS FNB group, 25 (74%) had a positive diagnosis with the second EUS FNB, 4 (12%) after surgery due to a second negative EUS FNB, 4 (12%) during clinical follow-up, and 1 (3%) after a third EUS FNB. Of the 25 patients diagnosed on the repeat EUS FNB, 17 (68%) had pancreatic adenocarcinomas, 2 (8%) neuroendocrine tumors, 2 (8%) other autoimmune pancreatitis, 2 (8%) chronic pancreatitis nodules, 1 (4%) renal cancer metastasis, and 1 (4%) other malignant diagnostic. There were no complications reported after the second EUS FNB in this study. CONCLUSION: repeat EUS FNB made a diagnosis in three fourths of patients with solid pancreatic lesions and a first negative EUS FNB, with 26% of benign lesions. This supports the repetition of EUS FNB sampling in this clinical situation.

Endoscopic submucosal dissection versus endoscopic mucosal resection for early esophageal adenocarcinoma.

OBJECTIVES: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) allow endoscopic resection of early esophageal adenocarcinoma. The choice between the two techniques takes into account the morphology of the lesion, and the experience of the endoscopist. The aim of this study was to compare EMR to ESD for the treatment of early esophageal adenocarcinoma. METHODS: Patients who underwent an endoscopic resection for esophageal adenocarcinomas between March 2015 and December 2019 were included. ESD was compared to EMR in terms of clinical, procedural, histologic, and oncologic outcomes. RESULTS: 85 patients were included: 57 ESD and 28 EMR. The median (IQR) diameter of the lesion was 20(15-25) mm in the ESD group, and 15(8-16) mm in the EMR group, p<0.01. ESD allowed en bloc resection in 100% of cases, and EMR in 39% of cases, p<0.001. The R0 and curative resection rate in the ESD group versus the EMR group were 88% and 67%, respectively, versus 21% and 11%, p<0.001. We recorded one severe adverse event, in the EMR group. After a median (IQR) follow-up of 27.5 (14.5-38.7) months, the local recurrence rate was 23% vs. 18% (p = 0.63), and the overall survival 89% vs. 86% (p = 0.72), in the ESD and EMR groups, respectively. CONCLUSION: ESD was as safe as EMR and allowed higher en bloc, R0 and curative resection rates. Although these results did not translate into long-term outcomes, these data prompt for a broader adoption of ESD for the resection of esophageal lesions suspected of harboring early esophageal adenocarcinoma.

[Well-differentiated neuroendocrine tumors of the digestive tract: Focus on pancreatic neuroendocrine tumors]. / Tumeurs neuroendocrines digestives bien différenciées: focus sur les tumeurs pancréatiques.

Pancreatic neuroendocrine tumors are rare tumors showing a rising incidence. They are well-differentiated tumors, classified by grade according to their Ki67 index value (grade 1 to 3). Pancreatic neuroendocrine tumors are mainly sporadic tumors but about 10% arise within endocrine tumor syndromes such as multiple endocrine neoplasia type 1. They can be responsible for functional syndromes or non-specific clinical symptoms depending on tumor extension. However, there is also an increase of incidental diagnoses of nonfunctional pancreatic neuroendocrine tumors with the widespread use of high-quality imaging techniques. About 50 % of pancreatic neuroendocrine tumors are diagnosed at a metastatic stage, with metastases often located in the liver. Chromogranin A, CT-scan and often an abdominal MRI, and functional imaging should be performed for tumor staging and follow-up. Imaging with PET/CT with 68Ga-labeled somatostatin analogues has the highest sensitivity for the diagnosis of pancreatic neuroendocrine tumors, while 18fluorodeoxyglucose PET/CT can sometimes be useful. Overall, they are rather indolent tumors with prolonged survival. Surgery is the recommended treatment in the localized setting, with the exception of small<2cm nonfunctional tumors that can be monitored with imaging techniques. For advanced tumors, there are several available treatments such as somatostatine analogues, chemotherapy, targeted therapies (sunitinib, everolimus), locoregional ablative therapies and Peptide Receptor Radiolabelled Therapy. The treatment strategy will depend on the initial tumor staging, tumor grade, aggressiveness and patient's choice.

Impact of Sarcopenia on Survival in Patients Treated with FOLFIRINOX in a First-Line Setting for Metastatic Pancreatic Carcinoma.

Sarcopenia, defined as decreased muscle mass and strength, can be evaluated by a computed tomography (CT) examination and might be associated with reduced survival in patients with carcinoma. The prognosis of patients with metastatic pancreatic carcinoma is poor. The FOLFIRINOX (a combination of 5-fluorouracil, irinotecan, and oxaliplatin) chemotherapy regimen is a validated first-line treatment option. We investigated the impact of sarcopenia on overall survival (OS) and progression-free survival (PFS) in patients with metastatic pancreatic carcinoma. Clinical data and CT examinations of patients treated with FOLFIRINOX were retrospectively reviewed. Sarcopenia was estimated using baseline CT examinations. Seventy-five patients were included. Forty-three (57.3%) were classified as sarcopenic. The median OS of non-sarcopenic and sarcopenic patients were 15.6 and 14.1 months, respectively (p = 0.36). The median PFS was 10.3 in non-sarcopenic patients and 9.3 in sarcopenic patients (p = 0.83). No differences in toxicity of FOLFIRINOX were observed. There was a trend towards a higher probability of short-term death (within 4 months of diagnosis) in sarcopenic patients. In this study, the detection of sarcopenia failed to predict a longer OS or PFS in selected patients deemed eligible by a physician for triplet chemotherapy and receiving the FOLFIRINOX regimen in a first-line setting, confirming the major importance of a comprehensive patient assessment by physicians in selecting the best treatment option.

Mechanisms of esophageal stricture after extensive endoscopic resection: a transcriptomic analysis.

Background and study aims Esophageal stricture is the most frequent adverse event after endoscopic resection for early esophageal neoplasia. Currently available treatments for the prevention of esophageal stricture are poorly effective and associated with major adverse events. Our aim was to identify transcripts specifically overexpressed or repressed in patients who have developed a post-endoscopic esophageal stricture, as potential targets for stricture prevention. Patients and methods We conducted a prospective single-center study in a tertiary endoscopy center. Patients scheduled for an endoscopic resection and considered at risk of esophageal stricture were offered inclusion in the study. The healthy mucosa and resection bed were biopsied on Days 0, 14, and 90. A transcriptomic analysis by microarray was performed, and the differences in transcriptomic profile compared between patients with and without esophageal strictures. Results Eight patients, four with esophageal stricture and four without, were analyzed. The mean ± SD circumferential extension of the mucosal defect was 85 ±â€Š11 %. The transcriptomic analysis in the resection bed at day 14 found an activation of the interleukin (IL)-1 group (Z score = 2.159, P  = 0.0137), while interferon-gamma (INFγ) and NUPR1 were inhibited (Z score = -2.375, P  = 0.0022 and Z score = -2.333, P  = 0.00131) in the stricture group. None of the activated or inhibited transcripts were still significantly so in any of the groups on Day 90. Conclusions Our data suggest that IL-1 inhibition or INFγ supplementation could constitute promising targets for post-endoscopic esophageal stricture prevention.

Airborne transmission of SARS-Cov2: What consequences for digestive endoscopy?

The SARS-Cov-2 disease disrupted essential hospital procedures, such as gastrointestinal (GI) endoscopy, due to concerns about air transmission and the risk of exposing health care workers. With the spread of the pandemic, air transmission was considered as the main source of SARS-Cov2 transmission. This raised the problem of transmission by aerosolization of viral particles in operating rooms as well as endoscopy units. This is in line with the known airborne transmission of many other respiratory viruses. The risk of SARS-Cov-2 transmission during GI endoscopy was initially reduced by controlled measures, involving personal protections (mask…), restricted access to endoscopy rooms, and detection of infected patients. Gastrointestinal endoscopy generates aerosols, which may carry viruses. In addition, the endoscopy system may facilitate the diffusion of virus particles or fomites considering the forced-air cooling system used to maintain a stable temperature inside the box (25°C). The volume of air that goes through the light source box is high (240-300 m3 for a 1-h period). Moreover, the light system contains an air pump to inflate air inside the gut lumen. In order to isolate people from hazard, different levels of protection and solutions to avoid airborne transmission of microorganisms should be proposed, such as the reinforcement of personal protective equipment, the change in the way people work and engineering control of the risk.

Artificial intelligence: A review of current applications in hepatocellular carcinoma imaging.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and currently the third-leading cause of cancer-related death worldwide. Recently, artificial intelligence (AI) has emerged as an important tool to improve clinical management of HCC, including for diagnosis, prognostication and evaluation of treatment response. Different AI approaches, such as machine learning and deep learning, are both based on the concept of developing prediction algorithms from large amounts of data, or big data. The era of digital medicine has led to a rapidly expanding amount of routinely collected health data which can be leveraged for the development of AI models. Various studies have constructed AI models by using features extracted from ultrasound imaging, computed tomography imaging and magnetic resonance imaging. Most of these models have used convolutional neural networks. These tools have shown promising results for HCC detection, characterization of liver lesions and liver/tumor segmentation. Regarding treatment, studies have outlined a role for AI in evaluation of treatment response and improvement of pre-treatment planning. Several challenges remain to fully integrate AI models in clinical practice. Future research is still needed to robustly evaluate AI algorithms in prospective trials, and improve interpretability, generalizability and transparency. If such challenges can be overcome, AI has the potential to profoundly change the management of patients with HCC. The purpose of this review was to sum up current evidence on AI approaches using imaging for the clinical management of HCC.

Predictive factors of radiofrequency ablation failure in the treatment of dysplastic Barrett's esophagus.

INTRODUCTION: Radiofrequency ablation (RFA) has become the recommended endoscopic treatment for flat dysplastic Barrett's esophagus. However, the outcomes of this treatment are variable across European countries. Our aim was to report the results of a French high-volume center, and to investigate factors associated with treatment failure. METHODS: We conducted a single-center retrospective study from a prospectively collected database from 2011 to 2020, including all consecutive patients treated with RFA for flat dysplastic Barrett's esophagus. The primary endpoint was the failure rate of esophageal radiofrequency treatment, defined as either persistence of intestinal metaplasia at the end of treatment, or neoplastic progression during RFA. RESULTS: 96 patients treated with a median of four RFA sessions for a mean C5M6 Barrett's esophagus were included in the analysis. Complete eradication of intestinal metaplasia and dysplasia were achieved in 59% and 79% of patients, respectively, resulting in a treatment failure rate of 41%. Ten patients experienced neoplastic progression during treatment. We recorded 14% of post-RFA esophageal strictures, all successfully treated by endoscopic dilatation. Univariate analysis identified the length of Barrett's esophagus and the absence of hiatal hernia as predictive factors for treatment failure, however not confirmed in multivariate analysis. CONCLUSION: In our experience, RFA of flat dysplastic Barrett's esophagus had a 41% treatment failure rate. The length of the Barrett's segment might be associated with treatment failure. Although our results confirm a role for RFA in the management of dysplastic Barrett's esophagus, the treatment failure rate was higher than expected. This suggest that endoscopists, even in high-volume centers, should receive specific training in RFA.

Imaging of Pancreatic Ductal Adenocarcinoma: An Update on Recent Advances.

Pancreatic ductal carcinoma (PDAC) is one of the leading causes of cancer-related death worldwide. Computed tomography (CT) remains the primary imaging modality for diagnosis of PDAC. However, CT has limitations for early pancreatic tumor detection and tumor characterization so that it is currently challenged by magnetic resonance imaging. More recently, a particular attention has been given to radiomics for the characterization of pancreatic lesions using extraction and analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence (AI) with the aim of better characterizing pancreatic lesions and providing a more precise assessment of tumor burden. This review article sums up recent advances in imaging of PDAC in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning. In addition, current applications of radiomics and AI in the field of PDAC are discussed.

Impact of Sarcopenia on Patients with Localized Pancreatic Ductal Adenocarcinoma Receiving FOLFIRINOX or Gemcitabine as Adjuvant Chemotherapy.

Background: Despite its toxicity, modified FOLFIRINOX is the main chemotherapy for localized, operable pancreatic adenocarcinomas. Sarcopenia is known as a factor in lower overall survival (OS). The purpose of this study was to assess the impact of sarcopenia on OS in patients with localized pancreatic ductal adenocarcinoma (PDAC) who received modified FOLFIRINOX or gemcitabine as adjuvant chemotherapy. Methods: Patients with operated PDAC who received gemcitabine-based (GEM group) or oxaliplatin-based (OXA group) adjuvant chemotherapy between 2008 and 2021 were retrospectively included. Sarcopenia was estimated on a baseline computed tomography (CT) examination using the skeletal muscular index (SMI). The primary evaluation criterion was OS. Secondary evaluation criteria were disease-free survival (DFS) and toxicity. Results: Seventy patients treated with gemcitabine-based (n = 49) and oxaliplatin-based (n = 21) chemotherapy were included, with a total of fifteen sarcopenic patients (eight in the GEM group and seven in the OXA group). The median OS was shorter in sarcopenic patients (25 months) compared to non-sarcopenic patients (158 months) (p = 0.01). A longer OS was observed in GEM non-sarcopenic patients (158 months) compared to OXA sarcopenic patients (14.4 months) (p < 0.01). The median OS was 157.7 months in the GEM group vs. 34.1 months in the OXA group (p = 0.13). No differences in median DFS were found between the GEM group and OXA group. More toxicity events were observed in the OXA group (50%) than in the GEM group (10%), including vomiting (p = 0.02), mucositis (p = 0.01) and neuropathy (p = 0.01). Conclusion: Sarcopenia is associated with a worse prognosis in patients with localized operated PDAC whatever the delivered adjuvant chemotherapy.

A new system to prevent SARS-CoV-2 and microorganism air transmission through the air circulation system of endoscopes.

Background and study aims Evidence for the modes of transmission of SARS-CoV-2 remains controversial. Recently, the potential for airborne spread of SARS-CoV-2 has been stressed. Air circulation in gastrointestinal light source boxes and endoscopes could be implicated in airborne transmission of microorganisms. Methods The ENDOBOX SC is a 600 × 600 mm cube designed to contain any type of machine used during gastrointestinal endoscopy. It allows for a 100-mm space between a machine and the walls of the ENDOBOX SC. To use the ENDOBOX SC, it is connected to the medical air system and it provides positive flow from the box to the endoscopy room. The ENDOBOX SC uses medical air to inflate the digestive tract and to decrease the temperature induced by the microprocessors or by the lamp. ENDOBOX SC has been investigated in different environments. Results An endoscopic procedure performed without ventilation was interrupted after 40 minutes to prevent computer damage. During the first 30 minutes, the temperature increased from 18 °C to 31 °C with a LED system. The procedure with fans identified variations in temperature inside the ENDOBOX SC from 21 to 26 °C (±â€Š5 °C) 1 hour after the start of the procedure. The temperature was stable for the next 3 hours. Conclusions ENDOBOX SC prevents the increase in temperature induced by lamps and processors, allows access to all necessary connections into the endoscopic columns, and creates a sterile and positive pressure volume, which prevents potential contamination from microorganisms.

Levels of Evidence Supporting United States Guidelines in Pancreatic Adenocarcinoma Treatment.

Cancer guidelines are ideally based on high levels of evidence (LOE). We aim to evaluate the LOE supporting recommendations in United States (US) guidelines on pancreatic adenocarcinoma (PDAC) treatment and its evolution over time. We searched for current guidelines from the American Society of Clinical Oncology (ASCO) and National Comprehensive Cancer Network (NCCN) and their prior publicly available versions on societies' websites and/or MEDLINE. We recorded the LOE and class of recommendation (opinion of the writing panel) for each recommendation. We defined high LOE as: a "high" quality of evidence from the GRADE methodology (ASCO) and "Category 1" (NCCN). Our main outcome was the proportion of PDAC recommendations supported by high LOE. Proportions of high LOE recommendations were 5% (2/40) and 8% (12/153) in current ASCO and NCCN guidelines, respectively. Less than 10% of class I recommendations were based on high LOE. For NCCN guidelines, the proportion of high LOE recommendations did not improve over time and only three recommendations increased their LOE. We identified a small percentage of high LOE recommendations for PDAC treatment in US guidelines. However, guidelines authors can only deal with the available evidence. The current framework of evidence should be challenged with consideration of observational evidence.

Outcomes of endoscopic mucosal resection for large superficial non-ampullary duodenal adenomas.

Endoscopic mucosal resection (EMR) is the recommended treatment for superficial non-ampullary duodenal epithelial tumors larger than 6 mm. This endoscopic technique carries a high risk of adverse events. Our aim was to identify the risk factors for adverse events following EMR for non-ampullary duodenal adenomatous lesions. We retrospectively analyzed a prospectively collected database of consecutive endoscopic resections for duodenal lesions at a tertiary referral center for therapeutic endoscopy. We analyzed patients with non-ampullary duodenal adenomatous lesions ≥ 10 mm resected by EMR, and searched for factors associated with adverse events after EMR. 167 duodenal adenomatous lesions, with a median size of 25 (25-40) mm, were resected by EMR between January 2015 and December 2020. Adverse events occurred in 37/167 (22.2%) after endoscopic resection, with 29/167 (17.4%) delayed bleeding, 4/167 (2.4%) immediate perforation and 4/167 (2.4%) delayed perforation. In logistic regression, the size of the lesion was the only associated risk factor of adverse events (OR = 2.81, 95% CI [1.27; 6.47], p = 0.012). Adverse events increased mean hospitalization time (7.7 ± 9 vs. 1.9 ± 1 days, p < 0.01). None of the currently recommended preventive methods, particularly clips, affected the adverse event rate. EMR of centimetric and supracentimetric duodenal adenomatous lesions carries a high risk of adverse events, increasing with the size of the lesion and with no benefit from any preventive method. These results suggest that these procedures should be performed in expert centers, and underline the need for novel endoscopic tools to limit the rate of adverse events.