Endoscopic management of gastric, duodenal and rectal NETs: Position paper from the Italian Association for Neuroendocrine Tumors (Itanet), Italian Society of Gastroenterology (SIGE), Italian Society of Digestive Endoscopy (SIED).

The present paper reflects the position of the Italian Association for Neuroendocrine Tumors (Itanet), the Italian Society of Gastroenterology (SIGE), and the Italian Society of Digestive Endoscopy (SIED) regarding the management of patients affected by gastric, duodenal, and rectal neuroendocrine neoplasms (NENs) amenable to endoscopic treatment. The key questions discussed in this paper are summarized in Table 1. Data were extracted from the MEDLINE database through searches; expert opinions and recommendations are provided in accordance with the available scientific evidence and the authors' expertise. Recommendations are presented alongside a level of evidence and grade of recommendation based on the GRADE system. This paper specifically focuses on subgroups of NENs considered suitable for endoscopic management according to current international guidelines: i. well-differentiated gastric neuroendocrine tumors (gNET) type 1 < 2 cm and selected cases of type 3; ii. well-differentiated duodenal, non-functioning, non-ampullary NET with size < 2 cm; and well-differentiated rectal NET with size < 2 cm.

Assessing generalisability of deep learning-based polyp detection and segmentation methods through a computer vision challenge.

Polyps are well-known cancer precursors identified by colonoscopy. However, variability in their size, appearance, and location makes the detection of polyps challenging. Moreover, colonoscopy surveillance and removal of polyps are highly operator-dependent procedures and occur in a highly complex organ topology. There exists a high missed detection rate and incomplete removal of colonic polyps. To assist in clinical procedures and reduce missed rates, automated methods for detecting and segmenting polyps using machine learning have been achieved in past years. However, the major drawback in most of these methods is their ability to generalise to out-of-sample unseen datasets from different centres, populations, modalities, and acquisition systems. To test this hypothesis rigorously, we, together with expert gastroenterologists, curated a multi-centre and multi-population dataset acquired from six different colonoscopy systems and challenged the computational expert teams to develop robust automated detection and segmentation methods in a crowd-sourcing Endoscopic computer vision challenge. This work put forward rigorous generalisability tests and assesses the usability of devised deep learning methods in dynamic and actual clinical colonoscopy procedures. We analyse the results of four top performing teams for the detection task and five top performing teams for the segmentation task. Our analyses demonstrate that the top-ranking teams concentrated mainly on accuracy over the real-time performance required for clinical applicability. We further dissect the devised methods and provide an experiment-based hypothesis that reveals the need for improved generalisability to tackle diversity present in multi-centre datasets and routine clinical procedures.

Circulating Proteins as Diagnostic Markers in Gastric Cancer.

Gastric cancer (GC) is a highly malignant disease affecting humans worldwide and has a poor prognosis. Most GC cases are detected at advanced stages due to the cancer lacking early detectable symptoms. Therefore, there is great interest in improving early diagnosis by implementing targeted prevention strategies. Markers are necessary for early detection and to guide clinicians to the best personalized treatment. The current semi-invasive endoscopic methods to detect GC are invasive, costly, and time-consuming. Recent advances in proteomics technologies have enabled the screening of many samples and the detection of novel biomarkers and disease-related signature signaling networks. These biomarkers include circulating proteins from different fluids (e.g., plasma, serum, urine, and saliva) and extracellular vesicles. We review relevant published studies on circulating protein biomarkers in GC and detail their application as potential biomarkers for GC diagnosis. Identifying highly sensitive and highly specific diagnostic markers for GC may improve patient survival rates and contribute to advancing precision/personalized medicine.

Upper Gastrointestinal Endoscopy Quality in Italy: A Nationwide Study.

BACKGROUND AND AIMS: International guidelines advise improving esophagogastroduodenoscopy (EGD) quality in Western countries, where gastric cancer is still diagnosed in advanced stages. This nationwide study investigated some indicators for the quality of EGD performed in endoscopic centers in Italy. METHODS: Clinical, endoscopic, and procedural data of consecutive EGDs performed in one month in the participating centers were reviewed and collected in a specific database. Some quality indicators before and during endoscopic procedures were evaluated. RESULTS: A total of 3,219 EGDs performed by 172 endoscopists in 28 centers were reviewed. Data found that some relevant information (family history for GI cancer, smoking habit, use of proton pump inhibitors) were not collected before endoscopy in 58.5-80.7% of patients. Pre-endoscopic preparation for gastric cleaning was routinely performed in only 2 (7.1%) centers. Regarding the procedure, sedation was not performed in 17.6% of patients, and virtual chromoendoscopy was frequently (>75%) used in only one (3.6%) center. An adequate sampling of the gastric mucosa (i.e., antral and gastric body specimens) was heterogeneously performed, and it was routinely performed only by 23% of endoscopists, and in 14.3% centers. CONCLUSIONS: Our analysis showed that the quality of EGD performed in clinical practice in Italy deserves to be urgently improved in different aspects.

Emilin2 fosters vascular stability by promoting pericyte recruitment.

Angiogenesis, the formation of the new blood vessels from pre-existing vasculature, is an essential process occurring under both normal and pathological conditions, such as inflammation and cancer. This complex process is regulated by several cytokines, growth factors and extracellular matrix components modulating endothelial cell and pericyte function. In this study, we discovered that the extracellular matrix glycoprotein Elastin Microfibril Interfacer 2 (Emilin2) plays a prominent role in pericyte physiology. This work was originally prompted by the observations that tumor-associated vessels from Emilin2-/- mice display less pericyte coverage, impaired vascular perfusion, and reduced drug efficacy, suggesting that Emilin2 could promote vessel maturation and stabilization affecting pericyte recruitment. We found that Emilin2 affects different mechanisms engaged in pericyte recruitment and vascular stabilization. First, human primary endothelial cells challenged with recombinant Emilin2 synthesized and released ∼ 2.1 and 1.2 folds more PDGF-BB and HB-EGF, two cytokines known to promote pericyte recruitment. We also discovered that Emilin2, by directly engaging α5ß1 and α6ß1 integrins, highly expressed in pericytes, served as an adhesion substrate and haptotactic stimulus for pericytes. Moreover, Emilin2 evoked increased NCadherin expression via the sphingosine-1-phosphate receptor, leading to enhanced vascular stability by fostering interconnection between endothelial cells and pericytes. Finally, restoring pericyte coverage in melanoma and ovarian tumor vessels developed in Emilin2-/- mice improved drug delivery to the tumors. Collectively, our results implicate Emilin2 as a prominent regulator of pericyte function and suggest that Emilin2 expression could represent a promising maker to predict the clinical outcome of patients with melanoma, ovarian, and potentially other forms of cancer.

Resident Esophageal Microbiota Dysbiosis Correlates with Cancer Risk in Barrett's Esophagus Patients and Is Linked to Low Adherence to WCRF/AICR Lifestyle Recommendations.

Esophageal adenocarcinoma (EAC) is the consequence of longstanding gastroesophageal reflux, which leads to inflammation and could cause Barrett's esophagus (BE), the main risk factor for EAC development. The 5 year survival rate of EAC is poor since the diagnosis occurs at the late stage of the disease. To improve patient management, a better comprehension of the mechanism undergoing the evolution through to adenocarcinoma is needed. Within this scenario, the resident microbiome investigation was studied. This study aimed to explore the esophageal microbial profile in patients affected by non-dysplastic BE, low- and high-grade dysplastic BE, and EAC to identify parameters characterizing cancer progression and to develop a score suitable for clinical practice to stratify cancer risk. The microbiota was investigated through the 16S rRNA gene sequencing of esophageal biopsies. The microbial composition was evaluated at each different taxonomic level along the disease progression. To further investigate bacteria potentially associated with cancer development, non-dysplastic and dysplastic/cancer patients were compared. The presence of the six significant microbial features with multivariate analysis was used to develop a multiparametric score (Resident Esophageal Microbial Dysbiosis Test) to predict the risk of progression toward EAC. Finally, the diagnostic ability of the test and its discrimination threshold for its ability to identify dysplastic/cancer patients were demonstrated. Since EAC has been related to obesity, the relationship between these microbial parameters and patients' diet/lifestyle habits was also investigated. Developing microbiome-based risk prediction models for esophageal adenocarcinoma onset could open new research avenues, demonstrating that the resident microbiome may be a valid cancer risk biomarker.

Factors influencing the presence of potentially explosive gases during colonoscopy: Results of the SATISFACTION study.

This study tested the hypothesis that bowel preparation with mannitol should not affect the colonic concentration of H2 and CH4 . Therefore, the SATISFACTION study, an international, multicenter, randomized, parallel-group phase II-III study investigated this issue. The phase II dose-finding part of the study evaluated H2 , CH4 , and O2 concentrations in 179 patients randomized to treatment with 50 g, 100 g, or 150 g mannitol. Phase III of the study compared the presence of intestinal gases in 680 patients randomized (1:1) to receive mannitol 100 g in single dose or a standard split-dose 2 L polyethylene glycol (PEG)-Asc preparation (2 L PEG-Asc). Phase II results showed that mannitol did not influence the concentration of intestinal gases. During phase III, no patient in either group had H2 or CH4 concentrations above the critical thresholds. In patients with H2 and/or CH4 levels above detectable concentrations, the mean values were below the risk thresholds by at least one order of magnitude. The results also highlighted the effectiveness of standard washing and insufflation maneuvers in removing residual intestinal gases. In conclusion, bowel cleansing with mannitol was safe as the concentrations of H2 and CH4 were the same as those found in patients prepared with 2 L PEG-Asc. In both groups, the concentrations of gases were influenced more by the degree of cleansing achieved and the insufflation and washing maneuvers performed than by the preparation used for bowel cleansing. The trial protocol was registered with ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT04759885) and with EudraCT (eudract_number: 2019-002856-18).

A multi-centre polyp detection and segmentation dataset for generalisability assessment.

Polyps in the colon are widely known cancer precursors identified by colonoscopy. Whilst most polyps are benign, the polyp's number, size and surface structure are linked to the risk of colon cancer. Several methods have been developed to automate polyp detection and segmentation. However, the main issue is that they are not tested rigorously on a large multicentre purpose-built dataset, one reason being the lack of a comprehensive public dataset. As a result, the developed methods may not generalise to different population datasets. To this extent, we have curated a dataset from six unique centres incorporating more than 300 patients. The dataset includes both single frame and sequence data with 3762 annotated polyp labels with precise delineation of polyp boundaries verified by six senior gastroenterologists. To our knowledge, this is the most comprehensive detection and pixel-level segmentation dataset (referred to as PolypGen) curated by a team of computational scientists and expert gastroenterologists. The paper provides insight into data construction and annotation strategies, quality assurance, and technical validation.

A DSC Test for the Early Detection of Neoplastic Gastric Lesions in a Medium-Risk Gastric Cancer Area.

In this study, we aimed to assess the accuracy of the proposed novel, noninvasive serum DSC test in predicting the risk of gastric cancer before the use of upper endoscopy. To validate the DSC test, we enrolled two series of individuals living in Veneto and Friuli-Venezia Giulia, Italy (n = 53 and n = 113, respectively), who were referred for an endoscopy. The classification used for the DSC test to predict gastric cancer risk combines the coefficient of the patient's age and sex and serum pepsinogen I and II, gastrin 17, and anti-Helicobacter pylori immunoglobulin G concentrations in two equations: Y1 and Y2. The coefficient of variables and the Y1 and Y2 cutoff points (>0.385 and >0.294, respectively) were extrapolated using regression analysis and an ROC curve analysis of two retrospective datasets (300 cases for the Y1 equation and 200 cases for the Y2 equation). The first dataset included individuals with autoimmune atrophic gastritis and first-degree relatives with gastric cancer; the second dataset included blood donors. Demographic data were collected; serum pepsinogen, gastrin G17, and anti-Helicobacter pylori IgG concentrations were assayed using an automatic Maglumi system. Gastroscopies were performed by gastroenterologists using an Olympus video endoscope with detailed photographic documentation during examinations. Biopsies were taken at five standardized mucosa sites and were assessed by a pathologist for diagnosis. The accuracy of the DSC test in predicting neoplastic gastric lesions was estimated to be 74.657% (65%CI; 67.333% to 81.079%). The DSC test was found to be a useful, noninvasive, and simple approach to predicting gastric cancer risk in a population with a medium risk of developing gastric cancer.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines.

BACKGROUND & AIMS: Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC. METHODS: After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%. RESULTS: The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients. CONCLUSIONS: The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.

An Italian prospective multicenter study on colonoscopy practice and quality: What has changed in the last 10 years.

BACKGROUND: A relevant number of adenomas can be missed during colonoscopy. AIMS: Assess the current status of colonoscopy procedures in Italian centers. METHODS: A prospective observational study involving 17 hospitals (34 endoscopists) included consecutive patients undergoing standard colonoscopy. In the first phase, endoscopists performed consecutive colonoscopies. In the second phase, retraining via an online learning platform was planned, while in the third phase data were collected analogously to phase 1. RESULTS: A total of 3,504 patients were enrolled. Overall, a BBPS score ≥6 was obtained in 95.6% of cases (94.8% and 96.9% in the pre- and post-training phases, respectively). 88.4% of colonoscopies had a withdrawal time ≥6 min (88.2% and 88.7% in the pre- and post-training phases). Median adenoma detection rate (ADR) was 39.1%, with no significant differences between the pre- and post-training phases (40.1% vs 36.9%; P = 0.83). In total, 81% of endoscopists had a ADR performance above the 25% threshold. CONCLUSION: High colonoscopy quality standards are achieved by the Italian hospitals involved. Quality improvement initiatives and repeated module-based colonoscopy-training have been promoted in Italy during the last decade, which appear to have had a significant impact on quality colonoscopy metrics together with the activation of colorectal cancer screening programs.

Increased Number of Colorectal Interval Cancers in Lynch Syndrome after the SARS-CoV-2 Pandemic: A Survey-Based Study.

BACKGROUND: Hereditary colorectal cancer syndromes require timely endoscopic surveillance. METHODS: This study evaluated the approach of Italian gastroenterologists to the management of such patients. It then assessed the impact of SARS-CoV-2. All members affiliated with the leading Italian gastroenterology societies (AIGO, SIED, and SIGE) received an online questionnaire. RESULTS: One hundred and twenty-one clinicians from 96 centers answered, not necessarily experts in the field (mean age 50.26 ± 11.22 years). Many collected family history for genetic risk assessment (74.4%), but only 14.0% used an online predictive software. 65.6% discussed cases in multidisciplinary units. Genetic analysis was available to most centers, but only a few hospitals offered dedicated endoscopy (19.0%), outpatient clinics (33.9%), or surgeries (23.1%). Since the start of the SARS-CoV-2 pandemic, the number of clinicians with a high volume of patients decreased (from 38.8% to 28.1%). Almost half of the responders (45.5%) reported a delay in the surveillance (median: 4-12 months). Ultimately, 30.6% detected one interval colorectal cancer in at least one of their patients. CONCLUSION: The SARS-CoV-2 pandemic directly affected the surveillance of hereditary colorectal cancer syndromes in Italy. Endoscopic surveillance should resume in all centers to avoid the possible long-term consequences of its interruption, especially for inherited colorectal cancer syndromes.

pCLE detects mucosal neoplastic vascular pattern in gastric linitis plastica.

Linitis plastica (LP) is a very aggressive and rare carcinoma with a scirrhous stroma that affects the submucosal and muscular layers of the stomach even without mucosal alterations. Lack of timely diagnosis is a crucial problem related to its prognosis and treatment. In this study, we investigated the LP-associated vascular pattern as a possible means to improve the diagnosis of these patients. During standard endoscopy, mucosal architecture, tortuosity and enlargement of vessels, as well as the presence of vascular leakage and efficiency of the blood flow were assessed in six LP patients using probe-based Confocal Laser Endomicroscopy (pCLE). In all LP patients, we detected abnormal changes in vasculature. The aberrant features of the vascular network were common to all LP patients examined and consisted of vessel enlargement, tortuosity, and leakage associated with the affected submucosal layer. This is the first study to highlight the presence of marked vascularization associated with LP, characterized by the presence of abnormal and non-functional vessels, similar to what is observed in neoplastic tissues. Therefore, the analysis of LP by pCLE may provide a new endoscopic approach and strategy to better define these patients.

Enteroscopy in diagnosis and treatment of small bowel bleeding: A Delphi expert consensus.

BACKGROUND: Enteroscopy plays an important role in the management of small bowel bleeding. However, current guidelines are not specifically designed for small bowel bleeding and recommendations from different international societies do not always align. Consequently, there is heterogeneity in the definitions of clinical entities, clinical practice policies, and adherence to guidelines among clinicians. This represents an obstacle to providing the best patient care and to obtain homogeneous data for clinical research. AIMS: The aims of the study were to establish a consensus on the definitions of bleeding entities and on the role of enteroscopy in the management of small bowel bleeding using a Delphi process. METHODS: A core group of eight experts in enteroscopy identified five main topics of small bowel bleeding management and drafted statements on each topic. An expert panel of nine gastroenterologists participated in three rounds of the Delphi process, together with the core group. RESULTS: A total of 33 statements were approved after three rounds of Delphi voting. CONCLUSION: This Delphi consensus proposes clear definitions and a unifying strategy to standardize the management of small bowel bleeding. Furthermore, it provides a useful guide in daily practice for both clinical and technical issues of enteroscopy.

Real-time gastric juice analysis with EndoFaster for H. pylori diagnosis: a large, multicentre study.

BACKGROUND: Helicobacter pylori infection is the main cause of the most frequent gastroduodenal diseases. Because its prevalence is decreasing in developed countries, gastric biopsies are negative in several patients. By measuring ammonium in the gastric juice, EndoFaster allows to exclude H. pylori infection during endoscopy. This study aimed to assess the accuracy of device versions working with either 6 ml or 3 ml of gastric juice. STUDY DESIGN: This prospective study involved 12 endoscopic units. During endoscopy, EndoFaster testing was performed and standard five gastric biopsies were taken. The accuracy was calculated by considering histological assessment as the gold standard for H. pylori diagnosis. RESULTS: Gastric juice analysis was attempted in 1279 patients, but it failed in 131 (15.5%) and in 10 (2.3%), with the 6 ml and the 3 ml device, respectively (P &lt; 0.001). Overall, EndoFaster detected H. pylori infection with an 86.3% sensitivity, 83.3% specificity, 52.7% positive predictive value, 96.6% negative predictive value and 83.8% accuracy. The performance was not affected either by ongoing proton pump inhibitor therapy or a previous H. pylori eradication. No significant difference in accuracy emerged between the two versions of the device. CONCLUSION: The novel version of the EndoFaster device operating with 3 ml gastric juice may be performed in virtually all patients, and it allows excluding H. pylori infection with a very high accuracy. Gastric biopsies can be avoided in a definite portion of cases without endoscopic lesions or other clinical indications.

New Generation Express View: An Artificial Intelligence Software Effectively Reduces Capsule Endoscopy Reading Times.

BACKGROUND: Reading capsule endoscopy (CE) is time-consuming. The Express View (EV) (IntroMedic, Seoul, Korea) software was designed to shorten CE video reading. Our primary aim was to evaluate the diagnostic accuracy of EV in detecting significant small-bowel (SB) lesions. We also compared the reading times with EV mode and standard reading (SR). METHODS: 126 patients with suspected SB bleeding and/or suspected neoplasia were prospectively enrolled and underwent SB CE (MiroCam®1200, IntroMedic, Seoul, Korea). CE evaluation was performed in standard and EV mode. In case of discrepancies between SR and EV readings, a consensus was reached after reviewing the video segments and the findings were re-classified. RESULTS: The completion rate of SB CE in our cohort was 86.5% and no retention occurred. The per-patient analysis of sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of EV compared to SR were 86%, 86%, 90%, 81%, and 86%, respectively, before consensus. After consensus, they increased to 97%, 100%, 100%, 96%, and 98%, respectively. The median reading time with SR and EV was 71 min (range 26−340) and 13 min (range 3−85), respectively (p < 0.001). CONCLUSIONS: The new-generation EV shows high diagnostic accuracy and significantly reduces CE reading times.

Real-time determination of gastric juice pH with EndoFaster® for atrophic gastritis assessment.

BACKGROUND: In patients with atrophic gastritis involving gastric body mucosa the pH value of gastric juice is distinctly increased, so that pH assessment would allow predict this precancerous lesion. We tested whether EndoFaster® - a device allowing real-time pH measure and H. pylori diagnosis - may optimize the need of taking gastric biopsies. METHODS: In this prospective, multicentre study, the accuracy of EndoFaster® for ruling out gastric atrophy involving corporal mucosa was assessed. Real-time pH and ammonium determination was performed by aspirating 3-6 ml gastric juice during endoscopy. Histology performed on 5 standard gastric biopsies was used as gold standard. RESULTS: A total of 1008 consecutive patients were observed in 12 centres. At histology, gastric body mucosa atrophy/metaplasia was detected in 65 (6.4%) cases, and a pH value >4.5 in the gastric juice was observed in 150 patients. The values of EndoFaster® performance in predicting the presence of atrophic gastritis were as follow: 51% sensitivity, 84% specificity, 18% PPV, 96% NPV, and 82% accuracy. The NPV value was not distinctly affected by neither ongoing proton pump inhibitor therapy nor H. pylori infection. By considering also data of ammonium concentrations, the values of EndoFaster® in detecting extensive atrophy on gastric mucosa were 74% sensitivity, 84% specificity, 24% PPV, 98% NPV, and 83% accuracy. CONCLUSION: The very high NPV of EndoFaster® might allow to safely rule out presence of atrophic gastritis, reducing the need of taking gastric biopsies in unselected patients managed in clinical practice.

HER2-CDH1 Interaction via Wnt/B-Catenin Is Associated with Patients' Survival in HER2-Positive Metastatic Gastric Adenocarcinoma.

Trastuzumab is a human epidermal growth factor receptor 2 (HER2) inhibitor used to treat HER2+ metastatic gastric cancer (mGC). The present study aims to investigate the relationship between CDH1 mRNA expression and HER2-positivity in mGC using a multiplexed gene expression profile in two series of gastric cancer (GC): Series 1 (n = 38): HER2+ and HER2- mGC; Series 2 (n = 36) HER2- GC with and without metastasis. To confirm the results, the same expression profiles were analyzed in 354 GC from The Cancer Genome Atlas (TCGA) dataset. The difference in gene expression connected HER2 overexpression with canonical wingless-type (Wnt)/ß-catenin pathway and immunohistochemical (IHC) expression loss of E-cadherin (E-CAD). CDH1 mRNA expression was simultaneously associated with the rs16260-A variant and an increase in E-CAD expression. Differences in retinoic acid receptor alfa (RARA), RPL19 (coding for the 60S ribosomal L19 protein), catenin delta 1 (CTNND1), and epidermal growth factor (EGF) mRNA levels-all included in the Wnt/ß-catenin pathway-were found associated with overall survival (OS). RARA, CTNND1, and EGF resulted in independent OS prognostic factors. EGF was confirmed as an independent factor along with TNM stage in HER2-overpressed mGC from TCGA collection. Our study highlighted factors involved in the WNT/ß-catenin pathway that interconnected E-CAD with HER2 overexpression and patient survival.

Colorectal cancer development is affected by the ECM molecule EMILIN-2 hinging on macrophage polarization via the TLR-4/MyD88 pathway.

BACKGROUND: Colorectal cancer is one of the most frequent and deadly tumors. Among the key regulators of CRC growth and progression, the microenvironment has emerged as a crucial player and as a possible route for the development of new therapeutic opportunities. More specifically, the extracellular matrix acts directly on cancer cells and indirectly affecting the behavior of stromal and inflammatory cells, as well as the bioavailability of growth factors. Among the ECM molecules, EMILIN-2 is frequently down-regulated by methylation in CRC and the purpose of this study was to verify the impact of EMILIN-2 loss in CRC development and its possible value as a prognostic biomarker. METHODS: The AOM/DSS CRC protocol was applied to Emilin-2 null and wild type mice. Tumor development was monitored by endoscopy, the molecular analyses performed by IHC, IF and WB and the immune subpopulations characterized by flow cytometry. Ex vivo cultures of monocyte/macrophages from the murine models were used to verify the molecular pathways. Publicly available datasets were exploited to determine the CRC patients' expression profile; Spearman's correlation analyses and Cox regression were applied to evaluate the association with the inflammatory response; the clinical outcome was predicted by Kaplan-Meier survival curves. Pearson correlation analyses were also applied to a cohort of patients enrolled in our Institute. RESULTS: In preclinical settings, loss of EMILIN-2 associated with an increased number of tumor lesions upon AOM/DSS treatment. In addition, in the early stages of the disease, the Emilin-2 knockout mice displayed a myeloid-derived suppressor cells-rich infiltrate. Instead, in the late stages, lack of EMILIN-2 associated with a decreased number of M1 macrophages, resulting in a higher percentage of the tumor-promoting M2 macrophages. Mechanistically, EMILIN-2 triggered the activation of the Toll-like Receptor 4/MyD88/NF-κB pathway, instrumental for the polarization of macrophages towards the M1 phenotype. Accordingly, dataset and immunofluorescence analyses indicated that low EMILIN-2 expression levels correlated with an increased M2/M1 ratio and with poor CRC patients' prognosis. CONCLUSIONS: These novel results indicate that EMILIN-2 is a key regulator of the tumor-associated inflammatory environment and may represent a promising prognostic biomarker for CRC patients.

Association between pancreatic intraductal papillary mucinous neoplasms and extrapancreatic malignancies: A systematic review with meta-analysis.

BACKGROUND: It is unclear whether patients with intraductal papillary mucinous neoplasia harbor a higher risk of developing extrapancreatic malignancies. AIMS: We performed a pooled estimate of the incidence of extrapancreatic malignancies in patients with intraductal papillary mucinous neoplasia, with a particular focus on the comparison to the general population. METHODS: Computerized bibliographic search of main databases was performed through February 2021. The primary endpoint was the pooled incidence of extrapancreatic malignancies in patients with intraductal papillary mucinous neoplasms. Additional outcome was the comparison between intraductal papillary mucinous neoplasia patients and the general population, expressed in terms of standardized incidence ratio along with 95% confidence intervals. RESULTS: Eighteen studies with 8709 patients were included. The pooled rate of metachronous extrapancreatic malignancies was 10 (6-13)/1000 persons-year. No difference was observed according to intraductal papillary mucinous neoplasia histology and sex, whereas a significantly superior incidence of extrapancreatic malignancies was observed in patients with main-duct (36.7%, 25.4%-48%) as compared to branch-duct intraductal papillary mucinous neoplasia (26.2%, 17.6%-34.8%; p = 0.03). Pooled standardized incidence ratio comparing expected rates in the general population was 1.01 (0.79-1.29); no difference was observed concerning rates of metachronous gastric cancer (standardized incidence ratio 1.60, 0.72-3.54) and colorectal cancer (1.29, 0.92-1.18), whereas biliary cancer was observed more frequently in intraductal papillary mucinous neoplasia patients (2.29, 1.07-4.93). CONCLUSION: Patients with intraductal papillary mucinous neoplasia harbor an overall rate of extrapancreatic malignancies as high as 27.3%. The rate of metachronous extrapancreatic malignancies is not superior to the general population.