Interplay between WNT/PI3K-mTOR axis and the microbiota in APC-driven colorectal carcinogenesis: data from a pilot study and possible implications for CRC prevention.

BACKGROUND: Wnt/ß-catenin signalling impairment accounts for 85% of colorectal cancers (CRCs), including sporadic and familial adenomatous polyposis (FAP) settings. An altered PI3K/mTOR pathway and gut microbiota also contribute to CRC carcinogenesis. We studied the interplay between the two pathways and the microbiota composition within each step of CRC carcinogenesis. METHODS: Proteins and target genes of both pathways were analysed by RT-qPCR and IHC in tissues from healthy faecal immunochemical test positive (FIT+, n = 17), FAP (n = 17) and CRC (n = 15) subjects. CRC-related mutations were analysed through NGS and Sanger. Oral, faecal and mucosal microbiota was profiled by 16 S rRNA-sequencing. RESULTS: We found simultaneous hyperactivation of Wnt/ß-catenin and PI3K/mTOR pathways in FAP-lesions compared to CRCs. Wnt/ß-catenin molecular markers positively correlated with Clostridium_sensu_stricto_1 and negatively with Bacteroides in FAP faecal microbiota. Alistipes, Lachnospiraceae, and Ruminococcaceae were enriched in FAP stools and adenomas, the latter also showing an overabundance of Lachnoclostridium, which positively correlated with cMYC. In impaired-mTOR-mutated CRC tissues, p-S6R correlated with Fusobacterium and Dialister, the latter also confirmed in the faecal-ecosystem. CONCLUSIONS: Our study reveals an interplay between Wnt/ß-catenin and PI3K/mTOR, whose derangement correlates with specific microbiota signatures in FAP and CRC patients, and identifies new potential biomarkers and targets to improve CRC prevention, early adenoma detection and treatment.

Development of desmoid tumours after ileorectal anastomosis versus ileal pouch-anal anastomosis in familial adenomatous polyposis.

BACKGROUND & AIMS: Desmoid tumours (DT) are an important cause of morbidity and mortality in patients with familial adenomatous polyposis (FAP). DT development might be related to the type and approach of colectomy. We aimed to compare DT development after colectomy with ileorectal anastomosis (IRA) and proctocolectomy with ileal pouch-anal anastomosis (IPAA). METHODS: We performed an international historical cohort study in FAP patients who underwent IRA or IPAA between 1961 and 2020. The primary outcome was the incidence of abdominal DT (either mesenteric, retroperitoneal or abdominal wall). Patients with a DT diagnosis before or at colectomy were excluded. Time to DT was considered censored at an eventual secondary proctectomy after IRA. We used multivariable Cox regression modelling to adjust for potential confounders. RESULTS: We analysed data from 852 patients: 514 after IRA and 338 after IPAA (median follow-up 21 and 16 years, respectively). DTs were diagnosed in 64 IRA patients (12%) and 66 IPAA patients (20%). The cumulative DT incidence at 5 and 10 years was 7.5% and 9.3% after open IRA and 4.7% and 10.9% after laparoscopic IRA. These estimates were 13.6% and 15.4% after open IPAA and 8.4% and 10.0% after laparoscopic IPAA. The post-operative risk was significantly higher after IPAA (p < 0.01) in multivariable analysis, while approach did not significantly influence the risk. CONCLUSIONS: The risk of developing an abdominal DT was found to be significantly higher after IPAA than after IRA. Postoperative DT risk should be taken into account when choosing between IRA and IPAA in FAP.

Updated European guidelines for clinical management of familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), gastric adenocarcinoma, proximal polyposis of the stomach (GAPPS) and other rare adenomatous polyposis syndromes: a joint EHTG-ESCP revision.

BACKGROUND: Hereditary adenomatous polyposis syndromes, including familial adenomatous polyposis and other rare adenomatous polyposis syndromes, increase the lifetime risk of colorectal and other cancers. METHODS: A team of 38 experts convened to update the 2008 European recommendations for the clinical management of patients with adenomatous polyposis syndromes. Additionally, other rare monogenic adenomatous polyposis syndromes were reviewed and added. Eighty-nine clinically relevant questions were answered after a systematic review of the existing literature with grading of the evidence according to Grading of Recommendations, Assessment, Development, and Evaluation methodology. Two levels of consensus were identified: consensus threshold (≥67% of voting guideline committee members voting either 'Strongly agree' or 'Agree' during the Delphi rounds) and high threshold (consensus ≥ 80%). RESULTS: One hundred and forty statements reached a high level of consensus concerning the management of hereditary adenomatous polyposis syndromes. CONCLUSION: These updated guidelines provide current, comprehensive, and evidence-based practical recommendations for the management of surveillance and treatment of familial adenomatous polyposis patients, encompassing additionally MUTYH-associated polyposis, gastric adenocarcinoma and proximal polyposis of the stomach and other recently identified polyposis syndromes based on pathogenic variants in other genes than APC or MUTYH. Due to the rarity of these diseases, patients should be managed at specialized centres.

The role of microbiota and its modulation in colonic diverticular disease.

BACKGROUND: Diverticular disease (DD) is a common condition in Western countries. The role of microbiota in the pathogenesis of DD and its related symptoms has been frequently postulated since most complications of this disease are bacteria-driven and most therapies rely on microbiota modulation. Preliminary data showed fecal microbial imbalance in patients with DD, particularly when symptomatic, with an increase of pro-inflammatory and potentially pathogenetic bacteria. In addition, bacterial metabolic markers can mirror specific pathways of the disease and may be even used for monitoring treatment effects. All treatments currently suggested for DD can affect microbiota structure and metabolome compositions. PURPOSE: Sparse evidence is available linking gut microbiota perturbations, diverticular disease pathophysiology, and symptom development. We aimed to summarize the available knowledge on gut microbiota evaluation in diverticular disease, with a focus on symptomatic uncomplicated DD, and the relative treatment strategies.

Management of familial adenomatous polyposis and MUTYH-associated polyposis; new insights.

Familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) are rare inherited polyposis syndromes with a high colorectal cancer (CRC) risk. Therefore, frequent endoscopic surveillance including polypectomy of relevant premalignant lesions from a young age is warranted in patients. In FAP and less often in MAP, prophylactic colectomy is indicated followed by lifelong endoscopic surveillance of the retained rectum after (sub)total colectomy and ileal pouch after proctocolectomy to prevent CRC. No consensus is reached on the right type and timing of colectomy. As patients with FAP and MAP nowadays have an almost normal life-expectancy due to adequate treatment of colorectal polyposis, challenges in the management of FAP and MAP have shifted towards the treatment of duodenal and gastric adenomas as well as desmoid treatment in FAP. Whereas up until recently upper gastrointestinal surveillance was mostly diagnostic and patients were referred for surgery once duodenal or gastric polyposis was advanced, nowadays endoscopic treatment of premalignant lesions is widely performed. Aiming to reduce polyp burden in the colorectum as well as in the upper gastrointestinal tract, several chemopreventive agents are currently being studied.

Chromoendoscopy Is Not Superior to White Light Endoscopy in Improving Adenoma Detection in Lynch Syndrome Cohort Undergoing Surveillance with High-Resolution Colonoscopy: A Real-World Evidence Study.

BACKGROUND: Endoscopic surveillance in patients with Lynch syndrome (LS) is crucial due to a genetically based high risk of colorectal cancer (CRC). We aimed to compare the adenoma detection rate (ADR) between high-resolution white light endoscopy (WLE) alone and WLE plus dye chromoendoscopy (CE) in a cohort of LS patients. METHODS: In a context of real-world data, we retrospectively enrolled 50 LS patients who had non-randomly undergone WLE versus CE surveillance examinations from 2007 to 2019. The 2 groups were compared at baseline (BL) in terms of the rate of patients with lesions and the number of lesions, and at follow-up (FU), to evaluate a possible enhanced detection rate. Longitudinal analysis of the effect of the endoscopy type on the main outcomes was performed by generalized linear mixed models. RESULTS: Forty-two patients had undergone at least one diagnostic colonoscopy. At BL and at FU analysis, we found no significant differences in detection rates and clinical-pathological features between WLE and CE groups. At the longitudinal analysis, an increase in the endoscopy rank (i.e., the position of each colonoscopy for all the colonoscopies that a patient had undergone) was associated with an increase in polyp detection rate (p = 0.006) and ADR (p = 0.005), while a trend toward significance (p = 0.069) was found for endoscopy type (CE vs. WLE) in the detection of serrated lesions. CONCLUSIONS: CE is not superior to high-resolution WLE in increasing the ADR. Even under standard WLE, an active and careful endoscopic surveillance of LS patients can prevent CRC.

Discovering the Mutational Profile of Early Colorectal Lesions: A Translational Impact.

Colorectal cancer (CRC) develops through a multi-step process characterized by the acquisition of multiple somatic mutations in oncogenes and tumor-suppressor genes, epigenetic alterations and genomic instability. These events lead to the progression from precancerous lesions to advanced carcinomas. This process requires several years in a sporadic setting, while occurring at an early age and or faster in patients affected by hereditary CRC-predisposing syndromes. Since advanced CRC is largely untreatable or unresponsive to standard or targeted therapies, the endoscopic treatment of colonic lesions remains the most efficient CRC-preventive strategy. In this review, we discuss recent studies that have assessed the genetic alterations in early colorectal lesions in both hereditary and sporadic settings. Establishing the genetic profile of early colorectal lesions is a critical goal in the development of risk-based preventive strategies.

Changes in digestive cancer diagnosis during the SARS-CoV-2 pandemic in Italy: A nationwide survey.

BACKGROUND: The SARS-CoV-2 pandemic has had a huge impact on healthcare systems, resulting in many routine diagnostic procedures either being halted or postponed. AIMS: To evaluate whether the diagnoses of colorectal, gastric and pancreatic cancers have been impacted by the SARS-CoV-2 pandemic in Italy. METHODS: A survey designed to collect the number of histologically-proven diagnoses of the three cancers in gastroenterology services across Italy from January 1 to October 31 in 2017-2020. Non-parametric ANOVA for repeated measurements was applied to compare distributions by years and macro-areas. RESULTS: Compared to 2019, in 2020 gastric cancer diagnoses decreased by 15.9%, CRC by 11.9% and pancreatic by 9.9%. CRC distributions showed significant differences between all years, stomach cancer between 2018 and 2020 and 2019-2020, and pancreatic cancer only between 2017 and 2019. The 2019-2020 comparison showed fewer CRC diagnoses in the North (-13.7%), Center (-16.5%) and South (-4.1%), fewer stomach cancers in the North (-19.0%) and South (-9.4%), and fewer pancreatic cancers in the North (-14.1%) and Center (-4.7%), with an increase in the South (+12.3%). Distributions of CRC and gastric cancer were significantly different between all years in the North. CONCLUSIONS: This survey highlights the concerning effects of the COVID-19 pandemic on the diagnostic yield of gastroenterology services for stomach, colorectal and pancreatic cancers in Italy.

Gastrointestinal mucosal damage in patients with COVID-19 undergoing endoscopy: an international multicentre study.

BACKGROUND: Although evidence suggests frequent gastrointestinal (GI) involvement during coronavirus disease 2019 (COVID-19), endoscopic findings are scarcely reported. AIMS: We aimed at registering endoscopic abnormalities and potentially associated risk factors among patients with COVID-19. METHODS: All consecutive patients with COVID-19 undergoing endoscopy in 16 institutions from high-prevalence regions were enrolled. Mann-Whitney U, χ2 or Fisher's exact test were used to compare patients with major abnormalities to those with negative procedures, and multivariate logistic regression to identify independent predictors. RESULTS: Between February and May 2020, during the first pandemic outbreak with severely restricted endoscopy activity, 114 endoscopies on 106 patients with COVID-19 were performed in 16 institutions (men=70.8%, median age=68 (58-74); 33% admitted in intensive care unit; 44.4% reporting GI symptoms). 66.7% endoscopies were urgent, mainly for overt GI bleeding. 52 (45.6%) patients had major abnormalities, whereas 13 bled from previous conditions. The most prevalent upper GI abnormalities were ulcers (25.3%), erosive/ulcerative gastro-duodenopathy (16.1%) and petechial/haemorrhagic gastropathy (9.2%). Among lower GI endoscopies, 33.3% showed an ischaemic-like colitis.Receiver operating curve analysis identified D-dimers >1850 ng/mL as predicting major abnormalities. Only D-dimers >1850 ng/mL (OR=12.12 (1.69-86.87)) and presence of GI symptoms (OR=6.17 (1.13-33.67)) were independently associated with major abnormalities at multivariate analysis. CONCLUSION: In this highly selected cohort of hospitalised patients with COVID-19 requiring endoscopy, almost half showed acute mucosal injuries and more than one-third of lower GI endoscopies had features of ischaemic colitis. Among the hospitalisation-related and patient-related variables evaluated in this study, D-dimers above 1850 ng/mL was the most useful at predicting major mucosal abnormalities at endoscopy. TRIAL REGISTRATION NUMBER: ClinicalTrial.gov (ID: NCT04318366).

Another Use for EUS: Removal of a Transesophageal-Migrated Mediastinal Foreign Body.

Removal of foreign bodies from the upper gastrointestinal tract, though a common occurrence, can be technically challenging and risky. We report the case of a young man that, after eating a pizza cooked in a wood-burning oven, reported a sense of foreign body. Though the first evaluation by fiberoptic laryngoscopy found no foreign body, after a few weeks, the patient was readmitted from the ER for worsening symptoms and fever. A CT scan showed a metallic mediastinal foreign body inside a large fluid collection. After multidisciplinary evaluation, an endoscopic removal was attempted by accessing the mediastinal collection through EUS-guided positioning of a Hot Axios™ stent. The cavity was drained by naso-esophageal suction. The foreign body was a fragment of the brush used to clean the oven. The patient is now doing well after 7 months.

Impact of SARS-CoV-2 Pandemic on Colorectal Cancer Screening Delay: Effect on Stage Shift and Increased Mortality.

BACKGROUND & AIMS: The SARS-CoV-2 pandemic had a sudden, dramatic impact on healthcare. In Italy, since the beginning of the pandemic, colorectal cancer (CRC) screening programs have been forcefully suspended. We aimed to evaluate whether screening procedure delays can affect the outcomes of CRC screening. METHODS: We built a procedural model considering delays in the time to colonoscopy and estimating the effect on mortality due to up-stage migration of patients. The number of expected CRC cases was computed by using the data of the Italian screened population. Estimates of the effects of delay to colonoscopy on CRC stage, and of stage on mortality were assessed by a meta-analytic approach. RESULTS: With a delay of 0-3 months, 74% of CRC is expected to be stage I-II, while with a delay of 4-6 months there would be a 2%-increase for stage I-II and a concomitant decrease for stage III-IV (P = .068). Compared to baseline (0-3 months), moderate (7-12 months) and long (> 12 months) delays would lead to a significant increase in advanced CRC (from 26% to 29% and 33%, respectively; P = .008 and P < .001, respectively). We estimated a significant increase in the total number of deaths (+12.0%) when moving from a 0-3-months to a >12-month delay (P = .005), and a significant change in mortality distribution by stage when comparing the baseline with the >12-months (P < .001). CONCLUSIONS: Screening delays beyond 4-6 months would significantly increase advanced CRC cases, and also mortality if lasting beyond 12 months. Our data highlight the need to reorganize efforts against high-impact diseases such as CRC, considering possible future waves of SARS-CoV-2 or other pandemics.

Is Ultrasound Elastography Useful in Predicting Clinically Relevant Pancreatic Fistula After Pancreatic Resection?: A Systematic Review and Meta-analysis.

OBJECTIVES: Ultrasound (US) elastography has been proposed for the non-invasive prediction of clinically relevant pancreatic fistula (CR-POPF) in patients undergoing pancreatic resection. We aimed to perform a systematic review with meta-analysis to assess the diagnostic value of US elastography in predicting CR-POPF. METHODS: MEDLINE via PubMed, Ovid Embase, Scopus, and Cochrane Library databases, and abstracts of international conference proceedings were searched up to April 20, 2020. Studies assessing the performance of abdominal US elastography in predicting CR-POPF in patients undergoing pancreatic resection were included. The quality of the studies was assessed using Quality Assessment of Diagnostic Accuracy Studies. RESULTS: Five studies, including 247 patients who underwent partial pancreatic resection of whom 72 patients experiencing CR-POPF, were selected. All studies performed US elastography in different pancreatic sites. The pooled mean strain value was lower in pancreatic segments of patients experiencing CR-POPF than in those without, with a pooled weighted mean difference of -0.187 (95% confidence intervals, -0.303 to -0.071; P = 0.002). There was low heterogeneity between studies (I = 7.6%), and all studies were at "high risk" or "unclear risk" of bias. CONCLUSIONS: This study provides evidence that US elastography values are statistically significantly lower in patients experiencing CR-POPF.