Bevacizumab plus FOLFIRI after failure of platinum-etoposide first-line chemotherapy in patients with advanced neuroendocrine carcinoma (PRODIGE 41-BEVANEC): a randomised, multicentre, non-comparative, open-label, phase 2 trial.

BACKGROUND: There is no standard second-line treatment after platinum-etoposide chemotherapy for gastroenteropancreatic neuroendocrine carcinoma. We aimed to evaluate the efficacy of FOLFIRI plus bevacizumab, and FOLFIRI alone, in this setting. METHODS: We did a randomised, non-comparative, open-label, phase 2 trial (PRODIGE 41-BEVANEC) at 26 hospitals in France. We included patients aged 18 years or older with locally advanced or metastatic gastroenteropancreatic neuroendocrine carcinoma or neuroendocrine carcinoma of unknown primary origin, documented progressive disease during or after first-line platinum-etoposide chemotherapy, and an Eastern Cooperative Oncology Group performance status of 0-2. Patients were randomly assigned (1:1; block size of three), without stratification, to receive FOLFIRI (irinotecan 180 mg/m2, calcium folinate 400 mg/m2 or levofolinate 200 mg/m2, and fluorouracil 400 mg/m2 bolus then 2400 mg/m2 over 46 h) plus bevacizumab 5 mg/kg or FOLFIRI alone, intravenously, every 2 weeks until disease progression or unacceptable toxicity. Neither patients nor investigators were masked to group assignment. The primary outcome was overall survival at 6 months after randomisation, evaluated in the modified intention-to-treat population (all enrolled and randomly assigned patients who received at least one cycle of FOLFIRI). This study is now complete and is registered with ClinicalTrials.gov, NCT02820857. FINDINGS: Between Sept 5, 2017, and Feb 8, 2022, 150 patients were assessed for eligibility and 133 were enrolled and randomly assigned: 65 to the FOLFIRI plus bevacizumab group and 68 to the FOLFIRI group. 126 patients (59 in the FOLFIRI plus bevacizumab group and 67 in the FOLFIRI group) received at least one cycle of FOLFIRI and were included in the modified intention-to-treat population, 83 (66%) of whom were male and 43 (34%) were female, and the median age of the patients was 67 years (IQR 58-73). The primary tumour location was colorectal in 38 (30%) of 126 patients, pancreatic in 34 (27%), gastro-oesophageal in 22 (17%), and unknown in 23 (18%). After a median follow-up of 25·7 months (95% CI 22·0-38·2), 6-month overall survival was 53% (80% CI 43-61) in the FOLFIRI plus bevacizumab group and 60% (51-68) in the FOLFIRI group. Grade 3-4 adverse events that occurred in at least 5% of patients were neutropenia (eight [14%] patients), diarrhoea (six [10%]), and asthenia (five [8%]) in the FOLFIRI plus bevacizumab group, and neutropenia (seven [10%]) in the FOLFIRI group. One treatment-related death (ischaemic stroke) occurred in the FOLFIRI plus bevacizumab group. INTERPRETATION: The addition of bevacizumab did not seem to increase the benefit of FOLFIRI with regard to overall survival. FOLFIRI could be considered as a standard second-line treatment in patients with gastroenteropancreatic neuroendocrine carcinoma. FUNDING: French Ministry of Health and Roche SAS.

Oral microbiota in obstructive sleep apnea patients: a systematic review.

PURPOSE: Evidence suggests that patients with obstructive sleep apnea (OSA) are at increased risk of suffering from periodontitis, a chronic inflammatory disease of the tooth-supporting tissues associated with a dysbiotic oral microbiota. This systematic review aims to explore the current literature about the composition of the oral microbiota in patients with OSA compared to those without OSA. METHODS: Medline, Embase, and Cochrane Library were searched in May 2022 to identify original articles investigating the oral microbiota composition and/or oral microbiome (any microbiological technique) of patients with OSA (adults or children) vs. controls. Case report, reviews, and animal studies were excluded. RESULTS: Of over 279 articles initially identified, 8 were selected, of which 3 dealt with pediatric patients. Overall, 344 patients with OSA and 131 controls were included. Five studies used salivary samples, 2 oral mucosal swabs, and 1 subgingival plaque sample. With different methods to characterize oral microbiota, 6/8 studies observed significant differences between patients with OSA patients and controls in the composition and relative abundance of several bacteria species/genera linked to periodontitis. CONCLUSION: Within the limitations of the available literature, the present systematic review indicates that OSA and related conditions (e.g., mouth breathing) are associated with different oral microbiota compositions, which may underlie the association between OSA and periodontitis.

Colorectal cancer-associated microbiota contributes to oncogenic epigenetic signatures.

Sporadic colorectal cancer (CRC) is a result of complex interactions between the host and its environment. Environmental stressors act by causing host cell DNA alterations implicated in the onset of cancer. Here we investigate the stressor ability of CRC-associated gut dysbiosis as causal agent of host DNA alterations. The epigenetic nature of these alterations was investigated in humans and in mice. Germ-free mice receiving fecal samples from subjects with normal colonoscopy or from CRC patients were monitored for 7 or 14 wk. Aberrant crypt foci, luminal microbiota, and DNA alterations (colonic exome sequencing and methylation patterns) were monitored following human feces transfer. CRC-associated microbiota induced higher numbers of hypermethylated genes in murine colonic mucosa (vs. healthy controls' microbiota recipients). Several gene promoters including SFRP1,2,3, PENK, NPY, ALX4, SEPT9, and WIF1 promoters were found hypermethylated in CRC but not in normal tissues or effluents from fecal donors. In a pilot study (n = 266), the blood methylation levels of 3 genes (Wif1, PENK, and NPY) were shown closely associated with CRC dysbiosis. In a validation study (n = 1,000), the cumulative methylation index (CMI) of these genes was significantly higher in CRCs than in controls. Further, CMI appeared as an independent risk factor for CRC diagnosis as shown by multivariate analysis that included fecal immunochemical blood test. Consequently, fecal bacterial species in individuals with higher CMI in blood were identified by whole metagenomic analysis. Thus, CRC-related dysbiosis induces methylation of host genes, and corresponding CMIs together with associated bacteria are potential biomarkers for CRC.

Contribution of Immune-Mediated Paraneoplastic Syndromes to Neurological Manifestations of Neuroendocrine Tumours: A Retrospective Study.

INTRODUCTION: Neurological symptoms associated with neuroendocrine tumours (NETs) may be related to metastatic disease or paraneoplastic syndromes (PNSs); these last are often associated with autoantibodies targeting various onconeural antigens. To better characterize neurological PNSs related to NETs, we report the largest case-series study to date. METHODS: We retrospectively reviewed the charts of all patients diagnosed with NETs of the gastrointestinal tract who presented with neurological symptoms at either of 2 tertiary academic hospitals (Henri Mondor and Beaujon, France) between 1994 and 2016. All patients underwent extensive neurological tests including clinical, laboratory, and radiological investigations. The clinical response to immunomodulating agents was recorded. RESULTS: In the 13 identified patients, the most common presentations were peripheral neuropathy (46.2%) and encephalopathy (26.6%). Of the 6 (53.3%) patients whose serum anti-neuronal antibodies were assayed, 5 had high titres. Short-term oral corticosteroid and immunosuppressant drug therapy was given to 4 of these patients, of whom 3 had a clinical response and 1 no response. Repeated high-dose intravenous immunoglobulin therapy induced a complete clinical response in 1 patient. Encephalopathy resolved fully after hepatectomy or intrahepatic chemoembolization for liver metastases in another 2 patients. DISCUSSION: The neurological symptoms associated with NETs may be due in part to autoimmune PNS. Based on experience at our 2 centres, we estimate that autoimmune PNS occurs in about 1% of patients with NETs. Early symptom recognition allows the initiation of effective treatments including corticosteroids, immunosuppressive drugs, and/or intravenous immunoglobulins.

Role of the intestinal microbiome in colorectal cancer surgery outcomes.

OBJECTIVES: Growing evidence supports the role of the intestinal microbiome in the carcinogenesis of colorectal cancers, but its impact on colorectal cancer surgery outcomes is not clearly defined. This systematic review aimed to analyze the association between intestinal microbiome composition and postoperative complication and survival following colorectal cancer surgery. METHODS: A systematic review was conducted according to the 2009 PRISMA guidelines. Two independent reviewers searched the literature in a systematic manner through online databases, including Medline, Scopus, Embase, Cochrane Oral Health Group Specialized Register, ProQuest Dissertations and Theses Database, and Google Scholar. Human studies investigating the association between the intestinal microbiome and the short-term (anastomotic leakage, surgical site infection, postoperative ileus) and long-term outcomes (cancer-specific mortality, overall and disease-free survival) of colorectal cancer surgery were selected. Patients with any stage of colorectal cancer were included. The Newcastle-Ottawa scale for case-control and cohort studies was used for the quality assessment of the selected articles. RESULTS: Overall, 8 studies (7 cohort studies and 1 case-control) published between 2014 and 2018 were included. Only one study focused on short-term surgical outcomes, showing that anastomotic leakage is associated with low microbial diversity and abundance of Lachnospiraceae and Bacteroidaceae families in the non-cancerous resection lines of the stapled anastomoses of colorectal cancer patients. The other 7 studies focused on long-term oncological outcomes, including survival and cancer recurrence. The majority of the studies (5/8) found that a higher level of Fusobacterium nucleatum adherent to the tumor tissue is associated with worse oncological outcomes, in particular, increased cancer-specific mortality, decreased median and overall survival, disease-free and cancer-specific survival rates. Also a high abundance of Bacteroides fragilis was found to be linked to worse outcomes, whereas the relative abundance of the Prevotella-co-abundance group (CAG), the Bacteroides CAG, and the pathogen CAG as well as Faecalibacterium prausnitzii appeared to be associated with better survival. CONCLUSIONS: Based on the limited available evidence, microbiome composition may be associated with colorectal cancer surgery outcomes. Further studies are needed to elucidate the role of the intestinal microbiome as a prognostic factor in colorectal cancer surgery and its possible clinical implications.

Histone deacetylase inhibition enhances antimicrobial peptide but not inflammatory cytokine expression upon bacterial challenge.

Antimicrobial peptides (AMP) are defense effectors of the innate immunity playing a crucial role in the intestinal homeostasis with commensals and protection against pathogens. Herein we aimed to investigate AMP gene regulation by deciphering specific characteristics allowing their enhanced expression among innate immune genes, particularly those encoding proinflammatory mediators. Our emphasis was on epigenetic regulation of the gene encoding the AMP ß-defensin 2 (HBD2), taken as a model of possibly specific induction, upon challenge with a commensal bacterium, compared with the proinflammatory cytokine IL-8. Using an in vitro model of colonic epithelial cells challenged with Escherichia coli K12, we showed that inhibition of histone deacetylases (HDAC) by trichostatin A dramatically enhanced induction of HBD2 expression, without affecting expression of IL-8. This mechanism was supported by an increased phosphorylation of histone H3 on serine S10, preferentially at the HBD2 promoter. This process occurred through activation of the IκB kinase complex, which also led to activation of NF-κB. Moreover, we demonstrated that NF-κB was modified by acetylation upon HDAC inhibition, partly by the histone acetyltransferase p300, and that both NF-κB and p300 supported enhanced induction of HBD2 expression. Furthermore, we identified additional genes belonging to antimicrobial defense and epithelial restitution pathways that showed a similar pattern of epigenetic control. Finally, we confirmed our finding in human colonic primary cells using an ex vivo organoid model. This work opens the way to use epigenetic pharmacology to achieve induction of epithelial antimicrobial defenses, while limiting the deleterious risk of an inflammatory response.

Endoscopic treatment of anastomotic biliary stricture after adult deceased donor liver transplantation with multiple plastic stents versus self-expandable metal stents: a systematic review and meta-analysis.

Anastomotic biliary strictures (ABSs) occur in up to 15% of patients after liver transplantation (LT). The aim of this study was to compare the efficacy and safety of self-expandable metal stents (SEMS) versus multiple plastic stents (MPS). Databases were searched through April 2017. The outcome measures were technical success, stricture resolution, recurrence and complications. We synthesized the findings descriptively and performed a meta-analysis. Three randomized controlled trials and one retrospective cohort study were identified, including 179 MPS and 119 SEMS patients. Outcome data were pooled in a meta-analysis that showed an advantage of SEMS in terms of the number of ERCP procedures (mean difference: 1.69 ERCP; 95% CI, 1-2.39; P < 0.00001) and treatment days (mean difference: 40.2 days; 95% CI, 3.9-76.4; P = 0.03), with no differences in terms of ABS resolution or recurrence. Fourteen case series reported MPS outcomes and fifteen reported SEMS outcomes, including 647 and 419 patients, respectively. Based on low-quality evidence, we cannot draw any reliable conclusions on the superiority of MPS or SEMS strategies. Even though shorter treatment times and fewer ERCP procedures support the use of SEMS, whether one technique has well-defined advantages over the other remains unclear.

A Study of Hypermethylated Circulating Tumor DNA as a Universal Colorectal Cancer Biomarker.

BACKGROUND: Circulating tumor DNA (ctDNA) has emerged as a good candidate for tracking tumor dynamics in different cancer types, potentially avoiding repeated tumor biopsies. Many different genes can be mutated within a tumor, complicating procedures for tumor monitoring, even with highly sensitive next-generation sequencing (NGS) strategies. Droplet-based digital PCR (dPCR) is a highly sensitive and quantitative procedure, allowing detection of very low amounts of circulating tumor genetic material, but can be limited in the total number of target loci monitored. METHODS: We analyzed hypermethylation of 3 genes, by use of droplet-based dPCR in different stages of colorectal cancer (CRC), to identify universal markers for tumor follow-up. RESULTS: Hypermethylation of WIF1 (WNT inhibitory factor 1) and NPY (neuropeptide Y) genes was significantly higher in tumor tissue compared to normal tissue, independently of tumor stage. All tumor tissues appeared positive for one of the 2 markers. Methylated ctDNA (MetctDNA) was detected in 80% of metastatic CRC and 45% of localized CRC. For samples with detectable mutations in ctDNA, MetctDNA and mutant ctDNA (MutctDNA) fractions were correlated. During follow-up of different stage CRC patients, MetctDNA changes allowed monitoring of tumor evolution. CONCLUSIONS: These results indicate that MetctDNA could be used as a universal surrogate marker for tumor follow-up in CRC patients, and monitoring MetctDNA by droplet-based dPCR could avoid the need for monitoring mutations.

(1)H NMR Spectroscopy of Fecal Extracts Enables Detection of Advanced Colorectal Neoplasia.

Colorectal cancer (CRC) is a growing cause of mortality in developing countries, warranting investigation into its etiopathogenesis and earlier diagnosis. Here, we investigated the fecal metabolic phenotype of patients with advanced colorectal neoplasia and controls using (1)H-nuclear magnetic resonance (NMR) spectroscopy and multivariate modeling. The fecal microbiota composition was assessed by quantitative real-time PCR as well as Wif-1 methylation levels in stools, serum, and urine and correlated to the metabolic profile of each patient. The predictivity of the model was 0.507 (Q(2)Y), and the explained variance was 0.755 (R(2)Y). Patients with advanced colorectal neoplasia demonstrated increased fecal concentrations of four short-chain fatty acids (valerate, acetate, propionate, and butyrate) and decreased signals relating to ß-glucose, glutamine, and glutamate. The predictive accuracy of the multivariate (1)H NMR model was higher than that of the guaiac-fecal occult blood test and the Wif-1 methylation test for predicting advanced colorectal neoplasia. Correlation analysis between fecal metabolites and bacterial profiles revealed strong associations between Faecalibacterium prausnitzii and Clostridium leptum species with short-chain fatty acids concentration and inverse correlation between Faecalibacterium prausnitzii and glucose. These preliminary results suggest that fecal metabonomics may potentially have a future role in a noninvasive colorectal screening program and may contribute to our understanding of the role of these dysregulated molecules in the cross-talk between the host and its bacterial microbiota.

Potential of fecal microbiota for early-stage detection of colorectal cancer.

Several bacterial species have been implicated in the development of colorectal carcinoma (CRC), but CRC-associated changes of fecal microbiota and their potential for cancer screening remain to be explored. Here, we used metagenomic sequencing of fecal samples to identify taxonomic markers that distinguished CRC patients from tumor-free controls in a study population of 156 participants. Accuracy of metagenomic CRC detection was similar to the standard fecal occult blood test (FOBT) and when both approaches were combined, sensitivity improved > 45% relative to the FOBT, while maintaining its specificity. Accuracy of metagenomic CRC detection did not differ significantly between early- and late-stage cancer and could be validated in independent patient and control populations (N = 335) from different countries. CRC-associated changes in the fecal microbiome at least partially reflected microbial community composition at the tumor itself, indicating that observed gene pool differences may reveal tumor-related host-microbe interactions. Indeed, we deduced a metabolic shift from fiber degradation in controls to utilization of host carbohydrates and amino acids in CRC patients, accompanied by an increase of lipopolysaccharide metabolism.

Neoadjuvant FOLFOX 4 versus FOLFOX 4 with Cetuximab versus immediate surgery for high-risk stage II and III colon cancers: a multicentre randomised controlled phase II trial--the PRODIGE 22--ECKINOXE trial.

BACKGROUND: In patients with high risk stage II and stage III colon cancer (CC), curative surgery followed by adjuvant FOLFOX-4 chemotherapy has become the standard of care. However, for 20 to 30% of these patients, the current curative treatment strategy of surgical excision followed by adjuvant chemotherapy fails either to clear locoregional spread or to eradicate distant micrometastases, leading to disease recurrence. Preoperative chemotherapy is an attractive concept for these CCs and has the potential to impact upon both of these causes of failure. Optimum systemic therapy at the earliest possible opportunity may be more effective at eradicating distant metastases than the same treatment given after the delay and immunological stress of surgery. Added to this, shrinking the primary tumor before surgery may reduce the risk of incomplete surgical excision, and the risk of tumor cell shedding during surgery. METHODS/DESIGN: PRODIGE 22--ECKINOXE is a multicenter randomized phase II trial designed to evaluate efficacy and feasibility of two chemotherapy regimens (FOLFOX-4 alone and FOLFOX-4 + Cetuximab) in a peri-operative strategy in patients with bulky CCs. Patients with CC deemed as high risk T3, T4 and/or N2 on initial abdominopelvic CT scan are randomized to either colectomy and adjuvant chemotherapy (control arm), or 4 cycles of neoadjuvant chemotherapy with FOLFOX-4 (for RAS mutated patients). In RAS wild-type patients a third arm testing FOLFOX+ cetuximab has been added prior to colectomy. Patients in the neoadjuvant chemotherapy arms will receive postoperative treatment for 4 months (8 cycles) to complete their therapeutic schedule. The primary endpoint of the study is the histological Tumor Regression Grade (TRG) as defined by Ryan. The secondary endpoints are: treatment strategy safety (toxicity, primary tumor related complications under chemotherapy, peri-operative morbidity), disease-free and recurrence free survivals at 3 years, quality of life, carcinologic quality and completeness of the surgery, initial radiological staging and radiological response to neoadjuvant chemotherapy, and the correlation between histopathological and radiological response. Taking into account a 50% prevalence of CC without RAS mutation, accrual of 165 patients is needed for this Phase II trial. TRIAL REGISTRATION: NCT01675999 (ClinicalTrials.gov).

Intravoxel incoherent motion (IVIM) MR imaging of colorectal liver metastases: are we only looking at tumor necrosis?

PURPOSE: To determine if intra-voxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters, including free molecular-based (D) and perfusion-related (D*, f) diffusion parameters, correlate with the degree of tumor necrosis and viable tumor in colo-rectal cancer (CRC) metastasis. MATERIALS AND METHODS: Fifteen patients referred for resection of liver metastases from CRC were retrospectively included in this Institutional Review Board approved study. An IVIM-DWI sequence was performed on a 1.5 Tesla MR imaging system, with 10 b factors (0, 10, 20, 30, 50, 80, 100, 200, 400 and 800 s/mm(2) ). Mean D, D*, f and apparent diffusion coefficient (ADC) values were determined in metastases with a longest diameter above 10 mm. Correlations between the diffusion parameters and the degree of liver tumor necrosis and viable tissue were determined (Spearman). RESULTS: Correlation between diffusion parameters and histopathological findings was performed in 35 hepatic metastases with a diameter of more than 10 mm (mean size of 17.9 mm; range, 1-68 mm). Both D (r = 0.36; P = 0.035) and ADC (r = 0.4; P = 0.02) correlated with the degree of tumor necrosis but not with viable tumor. CONCLUSION: ADC variation observed in CRC metastases following systemic chemotherapy reflects a specific increase in free-molecular diffusion (D), in itself correlated to the degree of metastasis necrosis.

Contribution of pks+ Escherichia coli (E. coli) to Colon Carcinogenesis.

Colorectal cancer (CRC) stands as a significant global health concern, ranking second in mortality and third in frequency among cancers worldwide. While only a small fraction of CRC cases can be attributed to inherited genetic mutations, the majority arise sporadically due to somatic mutations. Emerging evidence reveals gut microbiota dysbiosis to be a contributing factor, wherein polyketide synthase-positive Escherichia coli (pks+ E. coli) plays a pivotal role in CRC pathogenesis. pks+ bacteria produce colibactin, a genotoxic protein that causes deleterious effects on DNA within host colonocytes. In this review, we examine the role of the gut microbiota in colon carcinogenesis, elucidating how colibactin-producer bacteria induce DNA damage, promote genomic instability, disrupt the gut epithelial barrier, induce mucosal inflammation, modulate host immune responses, and influence cell cycle dynamics. Collectively, these actions foster a microenvironment conducive to tumor initiation and progression. Understanding the mechanisms underlying pks+ bacteria-mediated CRC development may pave the way for mass screening, early detection of tumors, and therapeutic strategies such as microbiota modulation, bacteria-targeted therapy, checkpoint inhibition of colibactin production and immunomodulatory pathways.

Gastric microbiota in patients with gastric MALT lymphoma according to Helicobacter pylori infection.

BACKGROUND: Gastric Mucosa Associated Lymphoid Tissue lymphoma (GML) development is triggered by Helicobacter pylori (H. pylori) infection. Little is known about the impact of H. pylori infection on gastric microbiota. METHODS: The gastric microbiota was retrospectively investigated using 16S rRNA gene sequencing in 32 patients with untreated GML (10 H. pylori-positive and 22 H. pylori-negative), 23 with remitted and 18 refractory GML and 35 controls. Differences in microbial diversity, bacterial composition and taxonomic repartition were assessed. RESULTS: There was no change in diversity and bacterial composition between GML and control patients taking into account H. pylori status. Differential taxa analysis identified specific changes associated with H. pylori-negative GML: the abundances of Actinobacillus, Lactobacillus and Chryseobacterium were increased while the abundances of Veillonella, Atopobium, Leptotrichia, Catonella, Filifactor and Escherichia_Shigella were increased in control patients. In patients with remitted GML, the genera Haemophilus and Moraxella were significantly more abundant than in refractory patients, while Atopobium and Actinomyces were significantly more abundant in refractory patients. CONCLUSION: Detailed analysis of the gastric microbiota revealed significant changes in the bacterial composition of the gastric mucosa in patients with GML that may have a role in gastric lymphomagenesis but not any new pathobionts.

Interest of Integrated Whole-Body PET/MR Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms: A Retro-Prospective Study.

INTRODUCTION AND AIM: Simultaneous positron emission tomography/magnetic resonance imaging (PET-MRI) combines the high sensitivity of PET with the high specificity of MRI and is a tool for the assessment of gastroenteropancreatic neuroendocrine neoplasms (G-NENs). However, it remains poorly evaluated with no clear recommendations in current guidelines. Thus, we evaluated the prognostic impact of PET-MRI in G-NEN patients. METHODS: From June 2017 to December 2021, 71 G-NEN patients underwent whole-body PET-MRI for staging and/or follow-up purposes. A whole-body emission scan with 18F-6-fluoro-L-dihydroxyphenylalanine (18FDOPA, n = 30), 18F-fluoro-2-deoxy-D-glucose (18FDG, n = 21), or 68Ga-(DOTA(0)-Phe(1)-Tyr(3))-octreotide (68Ga-DOTATOC, n = 20) with the simultaneous acquisition of a T1-Dixon sequence and diffusion-weighed imaging (DWI), followed by a dedicated step of MRI sequences with a Gadolinium contrast was performed. The patients underwent PET-MRI every 6-12 months during the follow-up period until death. Over this period, 50 patients with two or more PET-MRI were evaluated. RESULTS: The mean age was 61 [extremes, 31-92] years. At the baseline, PET-MRI provided new information in 12 cases (17%) as compared to conventional imaging: there were more metastases in eight, an undescribed location (myocardia) in two, and an unknown primary location in two cases. G grading at the baseline influenced overall survival. During the follow-up (7-381 months, mean 194), clinical and therapy managements were influenced by PET-MRI in three (6%) patients due to new metastases findings when neither overall, nor disease-free survivals in these two subgroups (n = 12 vs. n = 59), were different. CONCLUSION: Our study suggests that using PET/MRI with the appropriate radiotracer improves the diagnostic performance with no benefit on survival. Further studies are warranted to evaluate the cost-effectiveness of this procedure.

The colibactin-producing Escherichia coli alters the tumor microenvironment to immunosuppressive lipid overload facilitating colorectal cancer progression and chemoresistance.

Intratumoral bacteria flexibly contribute to cellular and molecular tumor heterogeneity for supporting cancer recurrence through poorly understood mechanisms. Using spatial metabolomic profiling technologies and 16SrRNA sequencing, we herein report that right-sided colorectal tumors are predominantly populated with Colibactin-producing Escherichia coli (CoPEC) that are locally establishing a high-glycerophospholipid microenvironment with lowered immunogenicity. It coincided with a reduced infiltration of CD8+ T lymphocytes that produce the cytotoxic cytokines IFN-γ where invading bacteria have been geolocated. Mechanistically, the accumulation of lipid droplets in infected cancer cells relied on the production of colibactin as a measure to limit genotoxic stress to some extent. Such heightened phosphatidylcholine remodeling by the enzyme of the Land's cycle supplied CoPEC-infected cancer cells with sufficient energy for sustaining cell survival in response to chemotherapies. This accords with the lowered overall survival of colorectal patients at stage III-IV who were colonized by CoPEC when compared to patients at stage I-II. Accordingly, the sensitivity of CoPEC-infected cancer cells to chemotherapies was restored upon treatment with an acyl-CoA synthetase inhibitor. By contrast, such metabolic dysregulation leading to chemoresistance was not observed in human colon cancer cells that were infected with the mutant strain that did not produce colibactin (11G5∆ClbQ). This work revealed that CoPEC locally supports an energy trade-off lipid overload within tumors for lowering tumor immunogenicity. This may pave the way for improving chemoresistance and subsequently outcome of CRC patients who are colonized by CoPEC.

Design of a specific colonic mucus marker using a human commensal bacterium cell surface domain.

Imaging living cells and organs requires innovative, specific, efficient, and well tolerated fluorescent markers targeting cellular components. Such tools will allow proceeding to the dynamic analysis of cells and the adaptation of tissues to environmental cues. In this study, we have identified and synthesized a novel non-toxic fluorescent marker allowing a specific fluorescent staining of the human colonic mucus. Our strategy to identify a molecule able to specifically bind to the human colonic mucus was on the basis of the mucus adhesion properties of commensal bacteria. We identified and characterized the mucus-binding property of a 70-amino acid domain (MUB(70)) expressed on the surface of Lactobacillus strains. The chemical synthesis of MUB(70) was achieved using the human commensal bacterium Lactobacillus reuteri AF120104 protein as a template. The synthesized Cy5-conjugated MUB(70) marker specifically stained the colonic mucus on fixed human, rabbit, and guinea pig tissues. Interestingly, murine tissue was not stained, suggesting significant differences in the composition of the murine colonic mucus. In addition, this marker stained the mucus of living cultured human colonic cells (HT29-MTX) and human colonic tissue explants. Using a biotinylated derivative of MUB(70), we demonstrated that this peptide binds specifically to Muc2, the most abundant secreted mucin, through its glycosylated moieties. Hence, Cy5-MUB(70) is a novel and specific fluorescent marker for mammalian colonic mucus. It may be used for live imaging analysis but also, as demonstrated in this study, as a marker for the diagnosis and the prognosis of colonic mucinous carcinomas.

Aberrant methylation of NPY, PENK, and WIF1 as a promising marker for blood-based diagnosis of colorectal cancer.

BACKGROUND: DNA methylation is a well-known epigenetic mechanism involved in epigenetic gene regulation. Several genes were reported hypermethylated in CRC, althought no gene marker was proven to be individually of sufficient sensitivity or specificity in routine clinical practice. Here, we identified novel epigenetic markers and assessed their combined use for diagnostic accuracy. METHODS: We used methylation arrays on samples from several effluents to characterize methylation profiles in CRC samples and controls, as established by colonoscopy and pathology findings, and selected two differentially methylated candidate epigenetic genes (NPY, PENK). To this gene panel we added WIF, on the basis of being reported in literature as silenced by promoter hypermethylation in several cancers, including CRC. We measured their methylation degrees by quantitative multiplex-methylation specific PCR (QM-MSP) on 15 paired carcinomas and adjacent non-cancerous colorectal tissues and we subsequently performed a clinical validation on two different series of 266 serums, subdivided in 32 CRC, 26 polyps, 47 other cancers and 161 with normal colonoscopy. We assessed the results by receiver operating characteristic curve (ROC), using cumulative methylation index (CMI) as variable threshold. RESULTS: We obtained CRC detection on tissues with both sensitivity and specificity of 100%. On serum CRC samples, we obtained sensitivity/specificity values of, e.g., 87%/80%, 78%/90% and 59%/95%, and negative predictive value/positive predictive value figures of 97%/47%, 95%/61% and 92%/70%. On serum samples from other cancers we obtained sensitivity/specificity of, e.g, 89%/25%, 43%/80% and 28%/91%. CONCLUSIONS: We showed the potential of NPY, PENK, and WIF1 as combined epigenetic markers for CRC diagnosis, both in tissue and serum and tested their use as serum biomarkers in other cancers. We optimized a QM-MSP for simultaneously quantifying their methylation levels. Our assay can be an effective blood test for patients where CRC risk is present but difficult to assess (e.g. mild symptoms with no CRC family history) and who would therefore not necessarily choose to go for further examination. This panel of markers, if validated, can also be a cost effective screening tool for the detection of asymptomatic cancer patients for colonoscopy.

Loss of symbiotic and increase of virulent bacteria through microbial networks in Lynch syndrome colon carcinogenesis.

Purpose: Through a pilot study, we performed whole gut metagenomic analysis in 17 Lynch syndrome (LS) families, including colorectal cancer (CRC) patients and their healthy first-degree relatives. In a second asymptomatic LS cohort (n=150) undergoing colonoscopy-screening program, individuals with early precancerous lesions were compared to those with a normal colonoscopy. Since bacteria are organized into different networks within the microbiota, we compared related network structures in patients and controls. Experimental design: Fecal prokaryote DNA was extracted prior to colonoscopy for whole metagenome (n=34, pilot study) or 16s rRNA sequencing (validation study). We characterized bacteria taxonomy using Diamond/MEGAN6 and DADA2 pipelines and performed differential abundances using Shaman website. We constructed networks using SparCC inference tools and validated the construction's accuracy by performing qPCR on selected bacteria. Results: Significant differences in bacterial communities in LS-CRC patients were identified, with an enrichment of virulent bacteria and a depletion of symbionts compared to their first-degree relatives. Bacteria taxa in LS asymptomatic individuals with colonic precancerous lesions (n=79) were significantly different compared to healthy individuals (n=71). The main bacterial network structures, constructed based on bacteria-bacteria correlations in CRC (pilot study) and in asymptomatic precancerous patients (validation-study), showed a different pattern than in controls. It was characterized by virulent/symbiotic co-exclusion in both studies and illustrated (validation study) by a higher Escherichia/Bifidobacterium ratio, as assessed by qPCR. Conclusion: Enhanced fecal virulent/symbiotic bacteria ratios influence bacterial network structures. As an early event in colon carcinogenesis, these ratios can be used to identify asymptomatic LS individual with a higher risk of CRC.

Focal loss of mural stratification as a radiological predictor for small bowel adenocarcinoma in Crohn's disease.

AIM: Patients with Crohn's disease (CD) are at higher risk of small bowel adenocarcinoma (SBA). We aimed to identify radiological predictors of SBA in CD. METHODS: We conducted a retrospective case-control study at two tertiary inflammatory bowel disease centers and identified CD patients diagnosed with SBA between 2003 and 2019. Patients were matched with up to four controls. Pre-operative imaging (magnetic resonance imaging (MRI) or computed tomography (CT)) were reviewed by three gastrointestinal radiologists. RESULTS: Nineteen patients with CD-associated SBA with a mean age of 54.9 and 32 matched controls were included. Mean length of small bowel involvement was 216 (± 188) mm in the SBA group versus 156 (± 167) mm in the control group (p = 0.76). Only 11.8 % of cases had a diagnosis of SBA made preoperatively. In univariate analysis, focal loss of mural stratification (odds ratio [OR], 11; 95%CI, 2.43-49.5, p = 0.002), and wall thickening (OR, 1.32; 95%CI, 1.05-1.66, p = 0.02) were significantly associated with SBA. After adjustment, focal loss of mural stratification was the only independent risk factor (OR, 11; 95 % CI, 2.43-49.5, p = 0.002). CONCLUSIONS: Focal loss of mural stratification was identified as a predictor of CD-associated SBA, which should be described in imaging reports and further validated.