Experimental Model of Biliary Tract Cancers: Subcutaneous Xenograft of Human Cell Lines in Immunodeficient Nude Mice.

The ectopic xenograft mouse model of cancer is a commonly employed tool for in vivo investigations, particularly for studying cell tumorigenicity and testing the efficacy and tolerability of systemic or local anti-cancer therapies. The model displays advantageous features with an easy-access to visualize and monitor tumor growth in real-time with a caliper. Although the tumor development occurs in an ectopic location, the histology of the tumor resembles that of human cancer upon pathological examination. This suggests that when human malignant cells are transplanted into immunocompromised mice, they can educate and attract murine cells from the surrounding environment to recapitulate a tumor structure. The experimental protocol for ectopic xenograft models is straightforward, making them reproducible, cost-effective, and conductive to shorter experimental durations. Here, we detail the utilization of ectopic xenograft models in studying biliary tract cancers (BTC), which involves subcutaneously grafting human BTC cell lines originating from different biliary tree locations onto immunocompromised nude mice.

Splenic vein tumor thrombosis is a major prognostic factor in distal pancreatic adenocarcinoma.

BACKGROUND: The prognostic value of splenic vessel involvement in distal pancreatic adenocarcinoma remains controversial. The aim of the study was to assess its prognostic relevance in a large multicenter cohort. METHODS: Patients who underwent pancreatosplenectomy for distal pancreatic adenocarcinoma were identified from 5 pancreatic surgical centers. A pathology review of the surgical specimens was performed to assess splenic vessel involvement, defined as invasion of the vessel's adventitia or deeper, and confirm the presence of splenic vein tumor thrombosis. Prognostic factors associated with overall and relapse-free survival were evaluated. RESULTS: 149 patients underwent upfront surgery. Splenic vascular involvement was observed in 69 of them (46.3%). A parietal infiltration of the splenic artery or splenic vein was observed in 26 (17.5%) and 49 patients (32.8%), respectively. A pathologic tumor thrombosis of the splenic vein was identified in 22 patients (14.8%) and associated with larger tumors (>20 mm) (P = .023), more perineural (P = .017), and lymphovascular (P = .002) invasion, and more positive lymph node (P = .001). After a median follow-up of 50.8 months (95% confidence interval: 44.3-57.3), the cumulative 5-year overall and relapse-free survival were 46.2% and 33%, respectively. In multivariate analysis, in addition to lymph node metastasis (hazard ratio = 1.8; 95% confidence interval [1.1-3.1]; P = .023) and perineural invasion (hazard ratio = 3.5; 95% confidence interval [1.3-9.7]; P = .016), presence of splenic vein tumor thrombosis was the only splenic vascular involvement that affected independently the overall survival (HR = 2.3; 95% confidence interval [ 1.3-4.3]; P = .006). CONCLUSION: In resectable distal pancreatic adenocarcinoma, a pathologic tumor thrombosis of the splenic vein is an independent prognostic factor of overall survival. To define the perioperative oncological strategy, a preoperative evaluation of splenic vessel involvement and thrombosis is needed.

Combined hepatocellular-cholangiocarcinoma compared to hepatocellular carcinoma and intrahepatic cholangiocarcinoma: Different survival, similar recurrence: Report of a large study on repurposed databases with propensity score matching.

BACKGROUND: Combined hepatocholangiocarcinoma is a rare cancer with a grim prognosis composed of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma morphologic patterns in the same tumor. The aim of this multicenter, international cohort study was to compare the oncologic outcomes after surgery of combined hepatocholangiocarcinoma to hepatocellular carcinoma and intrahepatic cholangiocarcinoma. METHODS: Patients treated by surgery for combined hepatocholangiocarcinoma, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma from 2000 to 2021 from multicenter international databases were analyzed retrospectively. Patients with combined hepatocholangiocarcinoma (cases) were compared with 2 control groups of hepatocellular carcinoma or intrahepatic cholangiocarcinoma, sequentially matched using a propensity score based on 8 preoperative characteristics. Overall and disease-free survival were compared, and predictors of mortality and recurrence were analyzed with Cox regression after propensity score matching. RESULTS: During the study period, 3,196 patients were included. Propensity score adjustment and 2 sequential matching processes produced a new cohort (n = 244) comprising 3 balanced groups was obtained (combined hepatocholangiocarcinoma = 56, intrahepatic cholangiocarcinoma = 66, and hepatocellular carcinoma = 122). Kaplan-Meier overall survival estimations at 1, 3, and 5 years were 67%, 45%, and 28% for combined hepatocholangiocarcinoma, 92%, 75%, and 55% for hepatocellular carcinoma, and 86%, 53%, and 42% for the intrahepatic cholangiocarcinoma group, respectively (P = .0014). Estimations of disease-free survival at 1, 3, and 5 years were 51%, 25%, and 17% for combined hepatocholangiocarcinoma, 63%, 35%, and 26% for the hepatocellular carcinoma group, and 51%, 31%, and 28% for the intrahepatic cholangiocarcinoma group, respectively (P = .19). Predictors of mortality were combined hepatocholangiocarcinoma subtype, metabolic syndrome, preoperative tumor markers alpha-fetoprotein and carbohydrate antigen 19-9, and satellite nodules, and recurrence was associated with satellite nodules rather than cancer subtype. CONCLUSION: Despite data limitations, overall survival among patients with combined hepatocholangiocarcinoma was worse than both groups and closer intrahepatic cholangiocarcinoma, whereas disease-free survival was similar among the 3 groups. Future research on immunophenotypic profiling may hold more promise than traditional nonmodifiable clinical characteristics (as found in this study) in predicting recurrence or response to salvage treatments.

Deep learning-based phenotyping reclassifies combined hepatocellular-cholangiocarcinoma.

Primary liver cancer arises either from hepatocytic or biliary lineage cells, giving rise to hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICCA). Combined hepatocellular- cholangiocarcinomas (cHCC-CCA) exhibit equivocal or mixed features of both, causing diagnostic uncertainty and difficulty in determining proper management. Here, we perform a comprehensive deep learning-based phenotyping of multiple cohorts of patients. We show that deep learning can reproduce the diagnosis of HCC vs. CCA with a high performance. We analyze a series of 405 cHCC-CCA patients and demonstrate that the model can reclassify the tumors as HCC or ICCA, and that the predictions are consistent with clinical outcomes, genetic alterations and in situ spatial gene expression profiling. This type of approach could improve treatment decisions and ultimately clinical outcome for patients with rare and biphenotypic cancers such as cHCC-CCA.

The liver in sickle cell disease.

Liver involvement in SCD patients is frequent but often misdiagnosed or underestimated, except in case of advanced liver diseases. Because of so far poorly recognized forms of chronic SCD-related vascular injury that can silently evolved towards end stages or facilitate ACLF, any persisting liver function tests abnormalities should be carefully investigated, following the above proposed algorithm. Work up and management must be considered multidisciplinary in relationship with a Hepatologist. Early SCD hepatopathy should prompt revision of SCD management to prevent further liver injury and decompensation, discussing transfusion exchanges and hydro urea when not yet initiated, and control for any cofactor of liver injury. The role of HSCT in early SCD hepatopathies also deserves evaluation. In advanced SCD hepatopathies, liver transplantation, which has been rarely performed so far, is the only therapeutic option associated with improved survival. It should definitely be discussed- either electively in case of decompensation in SCD cirrhosis or jaundice/recurrent cholangitis in cholestatic diseases, with excellent outcome, - or emergently in case of ALF or ACLF with more mitigate results. To improve knowledge and management of SCD liver diseases, creation of national and international registries, as well as longitudinal observational cohorts are encouraged.

Borderline Hepatocellular Adenomas: A Practical Diagnostic Approach Based on Pathologic and Molecular Features.

Borderline hepatocellular adenomas (BL-HCA) are characterized by focal architectural/cytologic atypia and reticulin loss, features that are insufficient for a definitive diagnosis of hepatocellular carcinoma (HCC). The diagnosis and management of BL-HCA are challenging as their biological behavior, especially in terms of malignant potential, is still debated. We aimed to compare the clinicopathologic and molecular features of BL-HCA with those of typical HCA (T-HCA), HCA with malignant transformation (HCC on HCA), and HCC to assess the risk of malignancy. One hundred six liver resection specimens were retrospectively selected from 2 reference centers, including 39 BL-HCA, 42 T-HCA, 12 HCC on HCA, and 13 HCC specimens. Somatic mutations, including TERT promoter mutations associated with HCA malignant transformation and the gene expression levels of 96 genes, were investigated in 93 frozen samples. Additionally, TERT promoter mutations were investigated in 44 formalin-fixed, paraffin-embedded samples. The clinical features of patients with BL-HCA were similar to those of patients with T-HCA, patients being mainly women (69%) with a median age of 37 years. The median tumor size was 7.5 cm, 64% of patients had a single nodule, and no recurrence was observed. Compared with T-HCA, BL-HCA was significantly enriched in ß-catenin-mutated HCA in exon 3 (41% vs 6%; P < .001). Unsupervised statistical analysis based on gene expression showed that BL-HCA overlapped with T-HCA and HCC on HCA, favoring a molecular continuum of the tumors. TERT promoter mutations were observed only in HCC on HCA (42%) and in HCC (38%). In conclusion, these results suggest that despite their worrisome morphologic features, the clinicopathologic and molecular features of BL-HCA are much closer to those of T-HCA than those of HCC on HCA or HCC. This strongly supports the usefulness of combining morphologic and molecular analyses in a practical diagnostic approach for guiding the management of BL-HCA.

[Development of the use of artificial intelligence in the management of chronic inflammatory bowel disease]. / Mise au point de l'utilisation de l'intelligence artificielle dans la prise en charge des maladies inflammatoires chroniques de l'intestin.

Complexity of inflammatory bowel diseases (IBD) lies on their management and their biology. Clinics, blood and fecal samples tests, endoscopy and histology are the main tools guiding IBD treatment, but they generate a large amount of data, difficult to analyze by clinicians. Because of its capacity to analyze large number of data, artificial intelligence is currently generating enthusiasm in medicine, and this technology could be used to improve IBD management. In this review, after a short summary on IBD management and artificial intelligence, we will report pragmatic examples of artificial intelligence utilisation in IBD. Lastly, we will discuss the limitations of this technology.

Residual Microscopic Peritoneal Metastases after Macroscopic Complete Cytoreductive Surgery for Advanced High-Grade Serous Ovarian Carcinoma: A Target for Folate Receptor Targeted Photodynamic Therapy?

Despite conventional treatment combining complete macroscopic cytoreductive surgery (CRS) and systemic chemotherapy, residual microscopic peritoneal metastases (mPM) may persist as the cause of peritoneal recurrence in 60% of patients. Therefore, there is a real need to specifically target these mPM to definitively eradicate any traces of the disease and improve patient survival. Therapeutic targeting method, such as photodynamic therapy, would be a promising method for such a purpose. Folate receptor alpha (FRα), as it is specifically overexpressed by cancer cells from various origins, including ovarian cancer cells, is a good target to address photosensitizing molecules. The aim of this study was to determine FRα expression by residual mPM after complete macroscopic CRS in patients with advanced high-grade serous ovarian cancer (HGSOC). A prospective study conducted between 1 June 2018 and 10 July 2019 in a single referent center accredited by the European Society of Gynecological Oncology for advanced EOC surgical management. Consecutive patients presenting with advanced HGSOC and eligible for complete macroscopic CRS were included. Up to 13 peritoneal biopsies were taken from macroscopically healthy peritoneum at the end of CRS and examined for the presence of mPM. In case of detection of mPM, a systematic search for RFα expression by immunohistochemistry was performed. Twenty-six patients were included and 26.9% presented mPM. In the subgroup of patients with mPM, FRα expression was positive on diagnostic biopsy before neoadjuvant chemotherapy for 67% of patients, on macroscopic peritoneal metastases for 86% of patients, and on mPM for 75% of patients. In the subgroup of patients with no mPM, FRα expression was found on diagnostic biopsy before neoadjuvant chemotherapy in 29% of patients and on macroscopic peritoneal metastases in 78% of patients. FRα is well expressed by patients with or without mPM after complete macroscopic CRS in patients with advanced HGSOC. In addition to conventional cytoreductive surgery, the use of a therapeutic targeting method, such as photodynamic therapy, by addressing photosensitizing molecules that specifically target FRα may be studied.

Nestin as a diagnostic and prognostic marker for combined hepatocellular-cholangiocarcinoma.

BACKGROUND & AIMS: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer (PLC) associated with a poor prognosis. Given the challenges in its identification and its clinical implications, biomarkers are critically needed. We aimed to investigate the diagnostic and prognostic value of the immunohistochemical expression of Nestin, a progenitor cell marker, in a large multicentric series of PLCs. METHODS: We collected 461 cHCC-CCA samples from 32 different clinical centers. Control cases included 368 hepatocellular carcinomas (HCCs) and 221 intrahepatic cholangiocarcinomas (iCCAs). Nestin immunohistochemistry was performed on whole tumor sections. Diagnostic and prognostic performances of Nestin expression were determined using receiver-operating characteristic curves and Cox regression modeling. RESULTS: Nestin was able to distinguish cHCC-CCA from HCC with AUCs of 0.85 and 0.86 on surgical and biopsy samples, respectively. Performance was lower for the distinction of cHCC-CCA from iCCA (AUCs of 0.59 and 0.60). Nestin, however, showed a high prognostic value, allowing identification of the subset of cHCC-CCA ("Nestin High", >30% neoplastic cells with positive staining) associated with the worst clinical outcome (shorter disease-free and overall survival) after surgical resection and liver transplantation, as well as when assessment was performed on biopsies. CONCLUSION: We show in different clinical settings that Nestin has diagnostic value and that it is a useful biomarker to identify the subset of cHCC-CCA associated with the worst clinical outcome. Nestin immunohistochemistry may be used to refine risk stratification and improve treatment allocation for patients with this highly aggressive malignancy. LAY SUMMARY: There are different types of primary liver cancers (i.e. cancers that originate in the liver). Accurately identifying a specific subtype of primary liver cancer (and determining its associated prognosis) is important as it can have a major impact on treatment allocation. Herein, we show that a protein called Nestin could be used to refine risk stratification and improve treatment allocation for patients with combined hepatocellular carcinoma, a rare but highly aggressive subtype of primary liver cancer.

Diversity of the nucleic acid forms of circulating HBV in chronically infected patients and its impact on viral cycle.

BACKGROUND: Besides the prototypical hepatitis B virus (HBV) infectious particle, which contains a full-length double-stranded DNA (flDNA), additional circulating virus-like particles, which carry pregenomic RNA (pgRNA), spliced1RNA (sp1RNA) or spliced-derived DNA (defDNA) forms have been described. We aimed to determine the level of these four circulating forms in patients and to evaluate their impact on viral lifecycle. METHODS: Chronic HBV untreated patients (n = 162), included in the HEPATHER cohort, were investigated. Pangenomic qPCRs were set up to quantify the four circulating forms of HBV nucleic acids (HBVnaf). In vitro infection assays were performed to address the impact of HBVnaf. RESULTS: Hierarchical clustering individualized two clusters of HBVnaf diversity among patients: (1) cluster 1 (C1) showing a predominance of flDNA; (2) cluster 2 (C2) showing various proportions of the different forms. HBeAg-positive chronic hepatitis phase and higher viral load (7.0 ± 6.4 vs 6.6 ± 6.2 Log10 copies/ml; p < 0.001) characterized C2 compared to C1 patients. Among the different HBVnaf, pgRNA was more prevalent in C1 patients with high vs low HBV viral load (22.1% ± 2.5% vs 4.1% ± 1.8% of HBVnaf, p < 0.0001) but remained highly prevalent in C2 patients, whatever the level of replication. C2 patients samples used in infection assays showed that: (1) HBVnaf secretion was independent of the viral strain; (2) the viral cycle efficiency differed according to the proportion of HBVnaf in the inoculum, independently of cccDNA formation. Inoculum enrichment before infection suggests that pgRNA-containing particles drive this impact on viral replication. CONCLUSION: Besides the critical role of HBV replication in circulating HBVnaf diversity, our data highlight an impact of this diversity on the dynamics of viral cycle. CLINICAL TRIAL REGISTRATION: Patients were included from a prospective multicenter French national cohort (ANRS CO22 HEPATHER, NCT01953458).

BRCA1 and RAD51C promotor methylation in human resectable pancreatic adenocarcinoma.

BACKGROUND: Homozygous Recombination Deficiency (HRD) is associated with sensitivity to PARP-inhibitors (PARPi) in different cancer types. In pancreatic adenocarcinoma (PA) the main cause of HRD is BRCA1/2 germline mutation and patients with mutations in BRCA1/2 may benefit from PARPi. Recently other mechanisms leading to HRD were described in different cancer types, including gene mutations and epigenetic changes such as promoter hypermethylation. In PA, BRCA1 promoter hypermethylation, a known mechanism of gene silencing, was recently described. However, results are discordant between North American studies (0.7% of PA) and Asian ones (up to 60% of PA) and the association with HRD is not clear. METHODS: Here, we developed 2 quantifications methods to explore BRCA1 and RAD51C promoter methylation in a series of 121 Formalin Fixed-Paraffin-Embedded (FFPE) specimens from resected PA without neoadjuvant treatment. The methylation-specific PCR was done with 2 different methods after DNA bisulfite conversion: a digital droplet PCR, and a PCR followed by capillary electrophoresis, to score the methylated / non methylated ratios in tumor samples. Methods were validated for specificity and sensibility using 100, 20, 10, 5 and 0% methylated commercial DNA for fragment analysis with a detection cutoff of 5-10%. Limit of blank was defined as 5 dropplets/20µL for RAD51C and 1 dropplet/20µL for BRCA1 for ddPCR. Samples were reviewed by a pathologist, macrodissected before DNA extraction to obtain 50-60% of tumoral cells. DNAs were treated for bisulfite conversion and analyzed using both methods in parallel to known positive and negative controls in each run. RESULTS AND CONCLUSION: No methylation at BRCA1 or RAD51C was found in this series of PA suggesting that HRD gene promoter methylation is a rare event in European patients.

Immune Profiling of Combined Hepatocellular- Cholangiocarcinoma Reveals Distinct Subtypes and Activation of Gene Signatures Predictive of Response to Immunotherapy.

PURPOSE: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare malignancy associated with an overall poor prognosis. We aimed to investigate the immune profile of cHCC-CCA and determine its impact on disease outcome. EXPERIMENTAL DESIGN: We performed a multicenter study of 96 patients with cHCC-CCA. Gene expression profile was analyzed using nCounter PanCancer IO 360 Panel. Densities of main immune cells subsets were quantified from digital slides of IHC stainings. Genetic alterations were investigated using targeted next-generation sequencing. RESULTS: Two main immune subtypes of cHCC-CCA were identified by clustering analysis: an "immune-high" (IH) subtype (57% of the cases) and an "immune-low" (IL) subtype (43% of the cases). Tumors classified as IH showed overexpression of genes related to immune cells recruitment, adaptive and innate immunity, antigen presentation, cytotoxicity, immune suppression, and inflammation (P < 0.0001). IH cHCC-CCAs also displayed activation of gene signatures recently shown to be associated with response to immunotherapy in patients with HCC. Quantification of immunostainings confirmed that IH tumors were also characterized by higher densities of immune cells. Immune subtypes were not associated with any genetic alterations. Finally, multivariate analysis showed that the IH subtype was an independent predictor of improved overall survival. CONCLUSIONS: We have identified a subgroup of cHCC-CCA that displays features of an ongoing intratumor immune response, along with an activation of gene signatures predictive of response to immunotherapy in HCC. This tumor subclass is associated with an improved clinical outcome. These findings suggest that a subset of patients with cHCC-CCA may benefit from immunomodulating therapeutic approaches.

Phase II study of pembrolizumab in refractory esophageal cancer with correlates of response and survival.

BACKGROUND: Immune checkpoint inhibitors have revolutionized cancer treatment, but the benefits in refractory patients with esophageal cancer have been modest. Predictors of response as well as new targets for novel therapeutic combinations are needed. In this phase 2 clinical trial, we tested single-agent pembrolizumab in patients with advanced esophageal cancer, who received at least one prior line of therapy. METHODS: Pembrolizumab 200 mg every 3 weeks was tested in 49 patients with refractory esophageal cancer: 39 with adenocarcinoma and 10 with esophageal squamous cell carcinoma. Major endpoints were radiological response by Immune-related Response Evaluation Criteria In Solid Tumors and survival. Tumor samples were evaluated for programmed cell death ligand 1 (PD-L1) expression, tumor mutational burden (TMB), and immune contexture by both NanoString mRNA expression analysis and flow cytometry. Peripheral blood mononuclear cells and a panel of circulating chemokines were also analyzed. RESULTS: The overall response rate (ORR) was 8% (4 of 49 patients; 95% CI 2.3% to 19.6%). Median overall survival (OS) was 5.8 months (95% CI 4.0 to 9.5). ORR and OS were not associated with histology. For PD-L1-positive patients, ORR was 13.3% (95% CI 1.7% to 40.5%) and median OS was 7.9 months (95% CI 4.7 to 15.5). A trend toward improved OS was observed in seven patients with a TMB ≥10 mut/Mb (p=0.086). Tumors with a PD-L1 Combined Positive Score ≥1 showed enrichment of LAG3 (p=0.005) and IDO1 (p=0.04) gene expression. Baseline levels of circulating CXCL10, interleukin 2 (IL2) receptor α (IL2RA) and IL6 were associated with survival: CXCL10 favorably, (HR 0.37, p=0.002 (progression-free survival); HR 0.55, p=0.018 (OS)); IL2RA and IL6 unfavorably (HR 1.57, p=0.020 for IL6 (OS); HR 2.36, p=0.025 for IL2RA (OS)). CONCLUSIONS: Pembrolizumab monotherapy was modestly effective in refractory esophageal cancer. Circulating CXCL10 at baseline appeared to be a robust predictor of response. Other T cell exhaustion markers are upregulated in PD-L1-positive patients, suggesting that immunotherapy combinations such as anti-LAG3/programmed cell death protein 1 (PD-1) or anti-IDO1/PD-1 may be of promise in refractory esophageal cancer.

Autoimmunity affecting the biliary tract fuels the immunosurveillance of cholangiocarcinoma.

Cholangiocarcinoma (CCA) results from the malignant transformation of cholangiocytes. Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are chronic diseases in which cholangiocytes are primarily damaged. Although PSC is an inflammatory condition predisposing to CCA, CCA is almost never found in the autoimmune context of PBC. Here, we hypothesized that PBC might favor CCA immunosurveillance. In preclinical murine models of cholangitis challenged with syngeneic CCA, PBC (but not PSC) reduced the frequency of CCA development and delayed tumor growth kinetics. This PBC-related effect appeared specific to CCA as it was not observed against other cancers, including hepatocellular carcinoma. The protective effect of PBC was relying on type 1 and type 2 T cell responses and, to a lesser extent, on B cells. Single-cell TCR/RNA sequencing revealed the existence of TCR clonotypes shared between the liver and CCA tumor of a PBC host. Altogether, these results evidence a mechanistic overlapping between autoimmunity and cancer immunosurveillance in the biliary tract.

Prognostic Relevance of Pancreatic Adenocarcinoma Whole-Tumor Transcriptomic Subtypes and Components.

PURPOSE: Our team previously defined six quantitative transcriptomic components, and a classification in five subtypes by association of these components. In this study, we compared the robustness of quantitative components and qualitative classifications from different transcriptomic profiling techniques, investigated their clinical relevance, and proposed a new prognostic model. EXPERIMENTAL DESIGN: A total of 210 patients from a multicentric cohort and 149 patients from a monocentric cohort were included in this study. RNA microarray profiles were obtained from 165 patients of the multicentric cohort. RNA sequencing (RNA-seq) profiles were obtained from all the patients. RESULTS: For the patients with both RNA microarray and RNA-seq profiles, the concordance in subtype assignment was partial with an 82.4% coherence rate. The correlation between the two technique projections of the six components ranged from 0.85 to 0.95, demonstrating an advantage of robustness. On the basis of the Akaike information criterion, the RNA components showed more prognostic value in univariate or multivariate models than the subtypes. Using the monocentric cohort for training, we developed a multivariate Cox regression model using all six components and clinicopathologic characteristics (node invasion and resection margins) on disease-free survival (DFS). This prognostic model was highly associated with DFS (P < 0.001). The evaluation of the model in the multicentric cohort showed significant association with DFS and overall survival (P < 0.001). CONCLUSIONS: We described the advantage of the prognostic value and robustness of the whole-tumor transcriptomic components than subtypes. We created and validated a new DFS-based multivariate Cox regression prognostic model, including six pancreatic adenocarcinoma transcriptomic component levels and pathologic characteristics.

Alternative splicing of viral transcripts: the dark side of HBV.

Regulation of alternative splicing is one of the most efficient mechanisms to enlarge the proteomic diversity in eukaryotic organisms. Many viruses hijack the splicing machinery following infection to accomplish their replication cycle. Regarding the HBV, numerous reports have described alternative splicing events of the long viral transcript (pregenomic RNA), which also acts as a template for viral genome replication. Alternative splicing of HBV pregenomic RNAs allows the synthesis of at least 20 spliced variants. In addition, almost all these spliced forms give rise to defective particles, detected in the blood of infected patients. HBV-spliced RNAs have long been unconsidered, probably due to their uneasy detection in comparison to unspliced forms as well as for their dispensable role during viral replication. However, recent data highlighted the relevance of these HBV-spliced variants through (1) the trans-regulation of the alternative splicing of viral transcripts along the course of liver disease; (2) the ability to generate defective particle formation, putative biomarker of the liver disease progression; (3) modulation of viral replication; and (4) their intrinsic propensity to encode for novel viral proteins involved in liver pathogenesis and immune response. Altogether, tricky regulation of HBV alternative splicing may contribute to modulate multiple viral and cellular processes all along the course of HBV-related liver disease.

Tumour and stroma RNA signatures predict more accurately distant recurrence than clinicopathological factors in resected pancreatic adenocarcinoma.

BACKGROUND: Few patients with pancreatic adenocarcinoma (PAC) are eligible for surgery. Patients with early relapse have a poor prognosis and might be better candidates for a medical approach. Clinical and pathological parameters only partially predict recurrence and are only obtained after surgery. PAC subtypes based on gene expression were proposed, and we assessed if they could predict the risk and type of recurrence independently of clinicopathological parameters. METHODS: Patients with curative-intent surgery for PAC without pretreatment were selected and divided into two independent cohorts defined as discovery (n = 381) and validation (n = 149) cohorts. Transcriptomic analyses were performed on formalin-fixed paraffin-embedded surgical samples to characterise tumour and stroma compartments using previously defined signatures. We associated molecular and clinicopathological characteristics with general, distant, and local recurrences using Cox regression analyses. RESULTS: We found that tumour biology predicted distant recurrence contrary to local recurrence, which was directly related to resection margin status. Pure basal-like and stroma-activated subtypes were strongly associated with distant recurrence, independently of clinicopathological factors (hazard ratios [HRs] = 5.85, p < 0.001 and HR = 1.75, p = 0.007, respectively). By dissecting tumoural and stromal compartments, we demonstrated that the basal-like tumour component positively correlated with distant recurrence in both cohorts (HR = 1.45, p < 0.001 and HR = 1.90, p < 0.001), whereas the inactive structural stroma component was protective against distant recurrence (HR = 0.68, p < 0.001 and HR = 0.72, p < 0.001). CONCLUSIONS: In addition to suggesting a different mechanism for local and distant relapse (incomplete resection and high metastatic potential, respectively), our results show the potency of molecular phenotype to predict patient outcome regarding distant recurrences.

Microscopic Peritoneal Residual Disease after Complete Macroscopic Cytoreductive Surgery for Advanced High Grade Serous Ovarian Cancer.

BACKGROUND: Epithelial ovarian cancers (EOC) are usually diagnosed at an advanced stage and managed by complete macroscopic cytoreductive surgery (CRS) and systemic chemotherapy. Peritoneal recurrence occurs in 60% of patients and may be due to microscopic peritoneal metastases (mPM) which are neither eradicated by surgery nor controlled by systemic chemotherapy. The aim of this study was to assess and quantify the prevalence of residual mPM after complete macroscopic CRS in patients with advanced high-grade serous ovarian cancer (HGSOC). METHODS: A prospective study conducted between 1 June 2018 and 10 July 2019 in a single referent center accredited by the European Society of Gynecological Oncology for advanced EOC management. Consecutive patients presenting with advanced HGSOC and eligible for complete macroscopic CRS were included. Up to 13 peritoneal biopsies were taken from macroscopically healthy peritoneum at the end of CRS and examined for the presence of mPM. A mathematical model was designed to determine the probability of presenting at least one mPM after CRS. RESULTS: 26 patients were included and 26.9% presented mPM. There were no differences in characteristics between patients with or without identified mPM. After mathematical analysis, the probability that mPM remained after complete macroscopic CRS in patients with EOC was 98.14%. CONCLUSION: Microscopic PM is systematically present after complete macroscopic CRS for EOC and could be a relevant therapeutic target. Adjuvant locoregional strategies to conventional surgery may improve survival by achieving microscopic CRS.

HPV Detection in Head and Neck Squamous Cell Carcinomas: What Is the Issue?

Besides classic tobacco and alcohol risk factors, human papillomavirus (HPV) plays a role in the development of a subset of head and neck squamous cell carcinomas (HNSCCs), and notably oropharynx squamous cell carcinomas (OPSCCs). HPV-induced OPSCCs have a different biological behavior and a better prognosis compared to non-HPV-induced OPSCCs and the eighth-edition TNM classification now separates these two entities. Therefore, determining the HPV status of patients with OPSCC is now essential for treatment, prognosis, and development of clinical trials. In this review, after reminding essential steps of HPV implication in the cell cycle, we describe the existing tools that are currently feasible in routine practice according to facilities available in health structures, with their benefits and drawbacks: HPV PCR, E6/E7 mRNA RT-PCR, E6/E7 mRNA in situ hybridization, HPV DNA in situ hybridization, and P16 immunochemistry. Besides these traditional HPV detection tools, novel diagnostic approaches are being evaluated for HPV-induced OPSCC "ultrastaging." E6 humoral response and ddPCR-detecting HPVct DNA are two techniques performed on blood and are therefore non-invasive. Baseline E6 humoral levels could have a prognostic value, and HPVct DNA could be helpful for HPV OPSCC recurrence monitoring. At last, next-generation sequencing (NGS)-based "capture HPV" is a technique feasible on biopsies and circulating DNA material. It helps characterize HPV integration status and sites, and it could define prognostic subgroups in HPV-induced OPSCC. These novel precision detection tools could be further integrated in the care of patients with HPV-induced OPSCC.

Freeze-dried fecal samples are biologically active after long-lasting storage and suited to fecal microbiota transplantation in a preclinical murine model of Clostridioides difficile infection.

Fecal microbiota transplantation is now recommended for treating recurrent forms of Clostridioides difficile infection. Recent studies have reported protocols using capsules of either frozen or freeze-dried stool allowing oral administration in in- and out-patient settings. However, a central question remains the viability, engraftment, and efficacy of the microbiome over time during storage life. This study shows that both the freeze-drying and freezing procedures for fecal samples allowed preserving viability, short-chain fatty acids concentration, and anti-Clostridioides difficile properties of microbiota without significant alteration after storage for 12 months. Fecal transplantation with freeze-dried microbiota allowed engraftment of microbiota leading to clearance of Clostridioides difficile infection in a preclinical murine model with a survival rate of 70% versus 53-60% in mice treated with frozen inocula, and 20% in the untreated group. Moreover, the freeze-dried powder can be used to fill oral hard capsules using a very low amount (0.5%) of glidant excipient, allowing oral formulation. Altogether, this study showed that freeze-dried inocula can be used for the treatment of Clostridioides difficile infection with long-lasting stability of the fecal microbiota. This formulation facilitates biobanking and allows the use of hard capsules, an essential step to simplify patient access to treatment.