Disrupted Resolution Mechanisms Favor Altered Phagocyte Responses in COVID-19.

[Figure: see text].

Cancer-associated fibroblasts in pancreatic cancer: new subtypes, new markers, new targets.

Cancer-associated fibroblasts (CAFs) have conflicting roles in the suppression and promotion of cancer. Current research focuses on targeting the undesirable properties of CAFs, while attempting to maintain tumour-suppressive roles. CAFs have been widely associated with primary or secondary therapeutic resistance, and strategies to modify CAF function have therefore largely focussed on their combination with existing therapies. Despite significant progress in preclinical studies, clinical translation of CAF targeted therapies has achieved limited success. Here we will review our emerging understanding of heterogeneous CAF populations in tumour biology and use examples from pancreatic ductal adenocarcinoma to explore why successful clinical targeting of protumourigenic CAF functions remains elusive. Single-cell technologies have allowed the identification of CAF subtypes with a differential impact on prognosis and response to therapy, but currently without clear consensus. Identification and pharmacological targeting of CAF subtypes associated with immunotherapy response offers new hope to expand clinical options for pancreatic cancer. Various CAF subtype markers may represent biomarkers for patient stratification, to obtain enhanced response with existing and emerging combinatorial therapeutic strategies. Thus, CAF subtyping is the next frontier in understanding and exploiting the tumour microenvironment for therapeutic benefit. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Periostin- and podoplanin-positive cancer-associated fibroblast subtypes cooperate to shape the inflamed tumor microenvironment in aggressive pancreatic adenocarcinoma.

Cancer-associated fibroblasts (CAFs) are orchestrators of the pancreatic ductal adenocarcinoma (PDAC) microenvironment. Previously we described four CAF subtypes with specific molecular and functional features. Here, we have refined our CAF subtype signatures using RNAseq and immunostaining with the goal of defining bioinformatically the phenotypic stromal and tumor epithelial states associated with CAF diversity. We used primary CAF cultures grown from patient PDAC tumors, human data sets (in-house and public, including single-cell analyses), genetically engineered mouse PDAC tissues, and patient-derived xenografts (PDX) grown in mice. We found that CAF subtype RNAseq signatures correlated with immunostaining. Tumors rich in periostin-positive CAFs were significantly associated with shorter overall survival of patients. Periostin-positive CAFs were characterized by high proliferation and protein synthesis rates and low α-smooth muscle actin expression and were found in peri-/pre-tumoral areas. They were associated with highly cellular tumors and with macrophage infiltrates. Podoplanin-positive CAFs were associated with immune-related signatures and recruitment of dendritic cells. Importantly, we showed that the combination of periostin-positive CAFs and podoplanin-positive CAFs was associated with specific tumor microenvironment features in terms of stromal abundance and immune cell infiltrates. Podoplanin-positive CAFs identified an inflammatory CAF (iCAF)-like subset, whereas periostin-positive CAFs were not correlated with the published myofibroblastic CAF (myCAF)/iCAF classification. Taken together, these results suggest that a periostin-positive CAF is an early, activated CAF, associated with aggressive tumors, whereas a podoplanin-positive CAF is associated with an immune-related phenotype. These two subpopulations cooperate to define specific tumor microenvironment and patient prognosis and are of putative interest for future therapeutic stratification of patients. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Pancreatic Cancer Organotypic Models.

Pancreatic cancer has a dismal prognosis for patients due to late diagnosis and ineffective treatment options. There is a desperate need for more accurate disease models to enable improved therapies and diagnostic tests to reach the clinic. Pancreatic tumours have a high content of desmoplastic stroma, which forms a stiff, hypoxic tumour mass and contributes significantly to tumour development and metastatic spread. Therefore, 2D cell culture is not sufficient for understanding the complex biology of this disease. 3D in vitro models offer a more representative method of culturing cells for research in the laboratory. There are many different 3D models that can be used in research, organoids formed from patient or murine tumours are grown embedded in collagen or matrigel matrices, giving the potential for screening treatment options and personalised therapy in the future. Also, organotypic models using pancreatic cancer cell lines and stromal cells can be easily manipulated to study different aspects of pancreatic cancer and new therapeutic options in the laboratory. There are new emerging pancreatic cancer 3D models being developed, including microchip technology or synthetic scaffolds instead collagen and matrigel. All of these 3D culturing methods give an advantage over traditional 2D cell culture and could lead to improved understanding of this disease, translating to a better prognosis for patients in the clinic.

Longitudinal profiling of circulating tumour DNA for tracking tumour dynamics in pancreatic cancer.

BACKGROUND: The utility of circulating tumour DNA (ctDNA) for longitudinal tumour monitoring in pancreatic ductal adenocarcinoma (PDAC) has not been explored beyond mutations in the KRAS proto-oncogene. Here, we aimed to characterise and track patient-specific somatic ctDNA variants, to assess longitudinal changes in disease burden and explore the landscape of actionable alterations. METHODS: We followed 3 patients with resectable disease and 4 patients with unresectable disease, including 4 patients with ≥ 3 serial follow-up samples, of whom 2 were rare long survivors (> 5 years). We performed whole exome sequencing of tumour gDNA and plasma ctDNA (n = 20) collected over a ~ 2-year period from diagnosis through treatment to death or final follow-up. Plasma from 3 chronic pancreatitis cases was used as a comparison for analysis of ctDNA mutations. RESULTS: We detected > 55% concordance between somatic mutations in tumour tissues and matched serial plasma. Mutations in ctDNA were detected within known PDAC driver genes (KRAS, TP53, SMAD4, CDKN2A), in addition to patient-specific variants within alternative cancer drivers (NRAS, HRAS, MTOR, ERBB2, EGFR, PBRM1), with a trend towards higher overall mutation loads in advanced disease. ctDNA alterations with potential for therapeutic actionability were identified in all 7 patients, including DNA damage response (DDR) variants co-occurring with hypermutation signatures predictive of response to platinum chemotherapy. Longitudinal tracking in 4 patients with follow-up > 2 years demonstrated that ctDNA mutant allele fractions and clonal trends were consistent with CA19-9 measurements and/or clinically reported disease burden. The estimated prevalence of 'stem clones' was highest in an unresectable patient where changes in ctDNA dynamics preceded CA19-9 levels. Longitudinal evolutionary trajectories revealed ongoing subclonal evolution following chemotherapy. CONCLUSION: These results provide proof-of-concept for the use of exome sequencing of serial plasma to characterise patient-specific ctDNA profiles, and demonstrate the sensitivity of ctDNA in monitoring disease burden in PDAC even in unresectable cases without matched tumour genotyping. They reveal the value of tracking clonal evolution in serial ctDNA to monitor treatment response, establishing the potential of applied precision medicine to guide stratified care by identifying and evaluating actionable opportunities for intervention aimed at optimising patient outcomes for an otherwise intractable disease.

High-grade mesenchymal pancreatic ductal adenocarcinoma drives stromal deactivation through CSF-1.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundance of stroma. Multiple molecular classification efforts have identified a mesenchymal tumor subtype that is consistently characterized by high-grade growth and poor clinical outcome. The relation between PDAC stroma and tumor subtypes is still unclear. Here, we aimed to identify how PDAC cells instruct the main cellular component of stroma, the pancreatic stellate cells (PSCs). We found in primary tissue that high-grade PDAC had reduced collagen deposition compared to low-grade PDAC. Xenografts and organotypic co-cultures established from mesenchymal-like PDAC cells featured reduced collagen and activated PSC content. Medium transfer experiments using a large set of PDAC cell lines revealed that mesenchymal-like PDAC cells consistently downregulated ACTA2 and COL1A1 expression in PSCs and reduced proliferation. We identified colony-stimulating factor 1 as the mesenchymal PDAC-derived ligand that deactivates PSCs, and inhibition of its receptor CSF1R was able to counteract this effect. In conclusion, high-grade PDAC features stroma that is low in collagen and activated PSC content, and targeting CSF1R offers direct options to maintain a tumor-restricting microenvironment.

Temporality of clinical factors associated with pancreatic cancer: a case-control study using linked electronic health records.

BACKGROUND: Pancreatic cancer risk is poorly quantified in relation to the temporal presentation of medical comorbidities and lifestyle. This study aimed to examine this aspect, with possible influence of demographics. METHODS: We conducted a retrospective case-control study on the ethnically-diverse population of East London, UK, using linked electronic health records. We evaluated the independent and two-way interaction effects of 19 clinico-demographic factors in patients with pancreatic cancer (N = 965), compared with non-malignant pancreatic conditions (N = 3963) or hernia (control; N = 4355), reported between April 1, 2008 and March 6, 2020. Risks were quantified by odds ratios (ORs) and 95% confidence intervals (CIs) from multivariable logistic regression models. RESULTS: We observed increased odds of pancreatic cancer incidence associated with recent-onset diabetes occurring within 6 months to 3 years before cancer diagnosis (OR 1.95, 95% CI 1.25-3.03), long-standing diabetes for over 3 years (OR 1.74, 95% CI 1.32-2.29), recent smoking (OR 1.81, 95% CI 1.36-2.4) and drinking (OR 1.76, 95% CI 1.31-2.35), as compared to controls but not non-malignant pancreatic conditions. Pancreatic cancer odds was highest for chronic pancreatic disease patients (recent-onset: OR 4.76, 95% CI 2.19-10.3, long-standing: OR 5.1, 95% CI 2.18-11.9), amplified by comorbidities or harmful lifestyle. Concomitant diagnosis of diabetes, upper gastrointestinal or chronic pancreatic conditions followed by a pancreatic cancer diagnosis within 6 months were common, particularly in South Asians. Long-standing cardiovascular, respiratory and hepatobiliary conditions were associated with lower odds of pancreatic cancer. CONCLUSIONS: Several factors are, independently or via effect modifications, associated with higher incidence of pancreatic cancer, but some established risk factors demonstrate similar magnitude of risk measures of developing non-malignant pancreatic conditions. The findings may inform refined risk-stratification strategies and better surveillance for high-risk individuals, and also provide a means for systematic identification of target population for prospective cohort-based early detection research initiatives.

PRIME-HCC: phase Ib study of neoadjuvant ipilimumab and nivolumab prior to liver resection for hepatocellular carcinoma.

BACKGROUND: After liver resection (LR), patients with hepatocellular cancer (HCC) are at high risk of recurrence. There are no approved anti-cancer therapies known to affect such risk, highlighting the acute need for novel systemic therapies to control the probability of disease relapse. Immunotherapy is expanding as a novel treatment option for HCC. Emerging data from cohort 4 of the CA209-040 study, which investigated the safety and preliminary efficacy of nivolumab/ipilimumab co-administration in advanced HCC, suggest that the combination can be delivered safely with an acceptable proportion of reversible grade 3-4 toxicities (27.1%) and a low discontinuation rate (2%) in patients with HCC. Here, we describe the design and rationale of PRIME-HCC, a two-part, multi-centre, phase Ib study to assess safety and bioactivity of the nivolumab/ipilimumab combination prior to LR in early-stage HCC. METHODS: The study involves an initial safety run-in phase (Part 1) to allow for preliminary safety characterisation within the first 6 patients enrolled and a subsequent expansion (Part 2). Ipilimumab will be administered once only on Day 1. Nivolumab will be administered on Day 1 and Day 22 (± 3 days) for a total of two 21-day cycles (i.e. 6 weeks of treatment). The primary objective of the study is to determine the safety and tolerability of the nivolumab/ipilimumab combination prior to LR. The secondary objective is to preliminarily characterize the efficacy of the combination prior to LR, including objective response rate (ORR) and pathologic response rates. Additional exploratory objectives include preliminary evidence of long-term disease control and to identify predictive correlates of response to the nivolumab/ipilimumab combination in HCC. DISCUSSION: The results of this study will help define the positioning of neoadjuvant nivolumab/ipilimumab combination in the perioperative management of HCC, with potential to improve survival outcomes in this patient population. TRIAL REGISTRATION: EudraCT Number: 2018-000987-27 Clinical trial registry & ID: ClinicalTrials.gov : NCT03682276 .

Impact of SARS-CoV-2 pandemic on pancreatic cancer services and treatment pathways: United Kingdom experience.

INTRODUCTION: The SARS-CoV-2 pandemic presented healthcare providers with an extreme challenge to provide cancer services. The impact upon the diagnostic and treatment capacity to treat pancreatic cancer is unclear. This study aimed to identify national variation in treatment pathways during the pandemic. METHODS: A survey was distributed to all United Kingdom pancreatic specialist centres, to assess diagnostic, therapeutic and interventional services availability, and alterations in treatment pathways. A repeating methodology enabled assessment over time as the pandemic evolved. RESULTS: Responses were received from all 29 centres. Over the first six weeks of the pandemic, less than a quarter of centres had normal availability of diagnostic pathways and a fifth of centres had no capacity whatsoever to undertake surgery. As the pandemic progressed services have gradually improved though most centres remain constrained to some degree. One third of centres changed their standard resectable pathway from surgery-first to neoadjuvant chemotherapy. Elderly patients, and those with COPD were less likely to be offered treatment during the pandemic. CONCLUSION: The COVID-19 pandemic has affected the capacity of the NHS to provide diagnostic and staging investigations for pancreatic cancer. The impact of revised treatment pathways has yet to be realised.

A combination of urinary biomarker panel and PancRISK score for earlier detection of pancreatic cancer: A case-control study.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with around 9% of patients surviving >5 years. Asymptomatic in its initial stages, PDAC is mostly diagnosed late, when already a locally advanced or metastatic disease, as there are no useful biomarkers for detection in its early stages, when surgery can be curative. We have previously described a promising biomarker panel (LYVE1, REG1A, and TFF1) for earlier detection of PDAC in urine. Here, we aimed to establish the accuracy of an improved panel, including REG1B instead of REG1A, and an algorithm for data interpretation, the PancRISK score, in additional retrospectively collected urine specimens. We also assessed the complementarity of this panel with CA19-9 and explored the daily variation and stability of the biomarkers and their performance in common urinary tract cancers. METHODS AND FINDINGS: Clinical specimens were obtained from multiple centres: Barts Pancreas Tissue Bank, University College London, University of Liverpool, Spanish National Cancer Research Center, Cambridge University Hospital, and University of Belgrade. The biomarker panel was assayed on 590 urine specimens: 183 control samples, 208 benign hepatobiliary disease samples (of which 119 were chronic pancreatitis), and 199 PDAC samples (102 stage I-II and 97 stage III-IV); 50.7% were from female individuals. PDAC samples were collected from patients before treatment. The samples were assayed using commercially available ELISAs. Statistical analyses were performed using non-parametric Kruskal-Wallis tests adjusted for multiple comparisons, and multiple logistic regression. Training and validation datasets for controls and PDAC samples were obtained after random division of the whole available dataset in a 1:1 ratio. The substitution of REG1A with REG1B enhanced the performance of the panel to detect resectable PDAC. In a comparison of controls and PDAC stage I-II samples, the areas under the receiver operating characteristic curve (AUCs) increased from 0.900 (95% CI 0.843-0.957) and 0.926 (95% CI 0.843-1.000) in the training (50% of the dataset) and validation sets, respectively, to 0.936 in both the training (95% CI 0.903-0.969) and the validation (95% CI 0.888-0.984) datasets for the new panel including REG1B. This improved panel showed both sensitivity (SN) and specificity (SP) to be >85%. Plasma CA19-9 enhanced the performance of this panel in discriminating PDAC I-II patients from controls, with AUC = 0.992 (95% CI 0.983-1.000), SN = 0.963 (95% CI 0.913-1.000), and SP = 0.967 (95% CI 0.924-1.000). We demonstrate that the biomarkers do not show significant daily variation, and that they are stable for up to 5 days at room temperature. The main limitation of our study is the low number of stage I-IIA PDAC samples (n = 27) and lack of samples from individuals with hereditary predisposition to PDAC, for which specimens collected from control individuals were used as a proxy. CONCLUSIONS: We have successfully validated our urinary biomarker panel, which was improved by substituting REG1A with REG1B. At a pre-selected cutoff of >80% SN and SP for the affiliated PancRISK score, we demonstrate a clinically applicable risk stratification tool with a binary output for risk of developing PDAC ('elevated' or 'normal'). PancRISK provides a step towards precision surveillance for PDAC patients, which we will test in a prospective clinical study, UroPanc.

Inter- and intra-tumoural heterogeneity in cancer-associated fibroblasts of human pancreatic ductal adenocarcinoma.

Cancer-associated fibroblasts (CAF) are orchestrators of the pancreatic ductal adenocarcinoma (PDAC) microenvironment. Stromal heterogeneity may explain differential pathophysiological roles of the stroma (pro- versus anti-tumoural) in PDAC. We hypothesised that multiple CAF functional subtypes exist in PDAC, that contribute to stromal heterogeneity through interactions with cancer cells. Using molecular and functional analysis of patient-derived CAF primary cultures, we demonstrated that human PDAC-derived CAFs display a high level of inter- and intra-tumour heterogeneity. We identified at least four subtypes of CAFs based on transcriptomic analysis, and propose a classification for human PDAC-derived CAFs (pCAFassigner). Multiple CAF subtypes co-existed in individual patient samples. The presence of these CAF subtypes in bulk tumours was confirmed using publicly available gene expression profiles, and immunostainings of CAF subtype markers. Each subtype displayed specific phenotypic features (matrix- and immune-related signatures, vimentin and α-smooth muscle actin expression, proliferation rate), and was associated with an assessable prognostic impact. A prolonged exposure of non-tumoural pancreatic stellate cells to conditioned media from cancer cell lines (cancer education experiment) induced a CAF-like phenotype, including loss of capacity to revert to quiescence and an increase in the expression of genes related to CAF subtypes B and C. This classification demonstrates molecular and functional inter- and intra-tumoural heterogeneity of CAFs in human PDAC. Our subtypes overlap with those identified from single-cell analyses in other cancers, and pave the way for the development of therapies targeting specific CAF subpopulations in PDAC. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

The integrin αvß6 drives pancreatic cancer through diverse mechanisms and represents an effective target for therapy.

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of less than 4% and desperately needs novel effective therapeutics. Integrin αvß6 has been linked with poor prognosis in cancer but its potential as a target in PDAC remains unclear. We report that transcriptional expression analysis revealed that high levels of ß6 mRNA correlated strongly with significantly poorer survival (n = 491 cases, p = 3.17 × 10-8 ). In two separate cohorts, we showed that over 80% of PDACs expressed αvß6 protein and that paired metastases retained αvß6 expression. In vitro, integrin αvß6 promoted PDAC cell growth, survival, migration, and invasion. Treatment of both αvß6-positive human PDAC xenografts and transgenic mice bearing αvß6-positive PDAC with the αvß6 blocking antibody 264RAD, combined with gemcitabine, significantly reduced tumour growth (p < 0.0001) and increased survival (log-rank test, p < 0.05). Antibody therapy was associated with suppression of tumour cell activity (suppression of pErk growth signals, increased apoptosis seen as activated caspase-3) and suppression of the pro-tumourigenic microenvironment (suppression of TGFß signalling, fewer αSMA-positive myofibroblasts, decreased blood vessel density). These data show that αvß6 promotes PDAC growth through both tumour cell and tumour microenvironment mechanisms and represents a valuable target for PDAC therapy. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

The Pancreatic Expression Database: 2018 update.

The Pancreatic Expression Database (PED, http://www.pancreasexpression.org) continues to be a major resource for mining pancreatic -omics data a decade after its initial release. Here, we present recent updates to PED and describe its evolution into a comprehensive resource for extracting, analysing and integrating publicly available multi-omics datasets. A new analytical module has been implemented to run in parallel with the existing literature mining functions. This analytical module has been created using rich data content derived from pancreas-related specimens available through the major data repositories (GEO, ArrayExpress) and international initiatives (TCGA, GENIE, CCLE). Researchers have access to a host of functions to tailor analyses to meet their needs. Results are presented using interactive graphics that allow the molecular data to be visualized in a user-friendly manner. Furthermore, researchers are provided with the means to superimpose layers of molecular information to gain greater insight into alterations and the relationships between them. The literature-mining module has been improved with a redesigned web appearance, restructured query platforms and updated annotations. These updates to PED are in preparation for its integration with the Pancreatic Cancer Research Fund Tissue Bank (PCRFTB), a vital resource of pancreas cancer tissue for researchers to support and promote cutting-edge research.

CRABP2 and FABP5 expression levels in diseased and normal pancreas.

Recently, stromal targeting, by agents such as All trans retinoic acid (ATRA), has been regarded as a promising avenue for the treatment of pancreatic ductal adenocarcinoma (PDAC). The intra-cellular transportation of ATRA to the nuclear receptors is performed by either: fatty acid binding protein 5 (FABP5) or cellular retinoic acid binding protein 2 (CRABP2), dictating the transcription of downstream genes and, thus, eventual cell phenotype. Here, we explored the levels of each protein, in pancreatic tissues of patients presenting with a range of pancreatic diseases (pancreatic ductal adenocarcinoma (PDAC), chronic pancreatitis (CP), cholangiocarcinoma (CC)). We demonstrate that there is a significantly lower CRABP2 and FABP5 expression in activated fibroblasts or pancreatic stellate cells (PSC) in PDAC, as well as other diseased pancreas as in CC and CP, versus quiescent fibroblasts. The quiescent fibroblasts consistently show a pattern of high FABP5:CRABP2 ratio, whereas PSC in all non-PDAC tissues showed a low FABP5:CRABP2 ratio. PSC in PDAC patients had a range of FABP5:CRABP2 ratios (high, even and low). There was a lower CRABP2 expression in cancerous epithelial cells (PDAC) versus normal epithelial cells. This is also present in other disease states (CP, CC). Contrasting to the patterns seen for fibroblasts, the FABP5 expression in PDAC epithelial cells matched that of the normal epithelial cells. However, the normal epithelial cells had a high FABP5:CRABP2 ratio, compared to the PDAC epithelial cells. These ratios may have correlation with tumor progression, and overall survival. These findings could be confirmed in in vitro cell lysates. CRABP2 and FABP5 levels and ratios could serve as valuable biomarkers.

A new pragmatic design for dose escalation in phase 1 clinical trials using an adaptive continual reassessment method.

BACKGROUND: A key challenge in phase I trials is maintaining rapid escalation in order to avoid exposing too many patients to sub-therapeutic doses, while preserving safety by limiting the frequency of toxic events. Traditional rule-based designs require temporarily stopping recruitment whilst waiting to see whether enrolled patients develop toxicity. This can be both inefficient and introduces logistic challenges to recruitment in the clinic. We describe a novel two-stage dose assignment procedure designed for a phase I clinical trial (STARPAC), where a good estimation of prior was possible. METHODS: The STARPAC design uses rule-based design until the first patient has a dose limiting toxicity (DLT) and then switches to a modified CRM, with rules to handle patient recruitment during follow-up of earlier patients. STARPAC design is compared via simulations with the TITE-CRM and 3 + 3 methods in various toxicity estimate (T1-5), rate of recruitment (R1-2), and DLT events timing (DT1-4), scenarios using several metrics: accuracy of maximum tolerated dose (MTD), numbers of DLTs, number of patients enrolled and those missed; duration of trial; and proportion of patients treated at the therapeutic dose or MTD. RESULTS: The simulations suggest that STARPAC design performed well in MTD estimation and in treating patients at the highest possible therapeutic levels. STARPAC and TITE-CRM were comparable in the number of patients required and DLTs incurred. The 3 + 3 design often had fewer patients and DLTs although this is due to its low escalation rate leading to poor MTD estimation. For the numbers of declined patients and MTD estimation 3 + 3 is uniformly worse, with STARPAC being better in those metrics for high toxicity scenarios and TITE-CRM better with low toxicity. In situations including doses with toxicities both above and below 30%, the STARPAC design outperformed TITE-CRM with respect to every metric. CONCLUSION: When considering doses with toxicities both above and below the target of 30% toxicities, the two-stage STARPAC dose escalation design provides a more efficient phase I trial design than either the traditional 3 + 3 or the TITE-CRM design. Trialists should model various designs via simulation to adopt the most efficient design for their clinical scenario. TRIAL REGISTRATION: Clinical Trials NCT03307148 (11 October 2017).

Neutrophil: Lymphocyte ratio as a method of predicting complications following hepatic resection for colorectal liver metastasis.

BACKGROUND AND OBJECTIVES: Approximately 30-50% of patients with colorectal cancer develop liver metastasis for which liver resection is the only hope for potential cure. However, hepatic resection is associated with considerable morbidity. The aim was to detect early complications by utilising the neutrophil: lymphocyte ratio (NLR). METHODS: We performed a retrospective cohort study of patients undergoing hepatic resection at a single institution between 2008 and 2016. Baseline demographics and complications within 30 days following surgery were recorded, with blood tests measured until day 7. Statistical analysis was performed using Mann Whitney and ROC analysis. RESULTS: One hundred eighty-eight operations were included. 47.3% had an associated complication, of which 31.46% were major. The median NLR was 6.31 across the cohort, 5.44 for uncomplicated procedures, 7.0 for complications and 10.65 in major complications. Median NLR was the best parameter for detecting major complications versus minor complications (AUC 0.74) as opposed to lymphocytes (AUC 0.65), neutrophils (AUC 0.60), and CRP (AUC 0.60). The diagnostic ability of NLR increased further when predicting major complications versus an uncomplicated recovery (AUC 0.78), and it was the only significant parameter in the early post-operative period on days 2, 3, and 4 (AUC 0.70, 0.72, and 0.75). CONCLUSIONS: The NLR may have a role in predicting complications following hepatic resection for CLM, and with earlier detection, potentially improving outcomes.

Expression of polymeric immunoglobulin receptor and stromal activity in pancreatic ductal adenocarcinoma.

BACKGROUND/OBJECTIVES: Polymeric immunoglobulin receptor (pIgR) traffics Immunoglobulins (IgA and IgM) through epithelial cells in normal mucosae but neither are expressed in the normal pancreas. Recent work from our laboratory suggested pIgR may be upregulated in pancreatic ductal adenocarcinoma (PDAC). Our aim was to assess the role of pIgR in human PDAC. METHODS: pIgR expression was manipulated (siRNA and shRNA) in cell lines to evaluate its subsequent effect on cell behaviour in 2D assays as well as 3D organotypics models. Tissue Microarrays of 88 patients with PDAC were analysed after pIgR, αSMA, E-Cadherin and Picrosirius Red staining to assess their role as a combined bio-marker panel. RESULTS: Cytokines such as interleukin 4 (IL4) and Tumour Necrosis Factor (TNFα) could not modulate pIgR expression in PDAC cell lines despite this effect being seen in other studies. Down-regulation in pIgR expression in Capan1 cancer cell line resulted in reduction of cellular proliferation, adhesion and migration in 2D assays. In 3D physiomimetic organotypic models, pIgR downregulation resulted in reduced cancer cell invasion, alteration of apico-basal polarity and diminished stromal activity. In human PDAC, decreased E-cadherin expression correlates with increased pIgR expression through pancreatic intra-epithelial neoplasia (PanIN) progression. In combination with enhanced stromal indices (α-smooth muscle action (SMA) and Picrosirius red), low pIgR scores had a trend towards better survival. CONCLUSION: pIgR may be involved in PDAC progression and may be linked stromal activity. Further work on its precise role is mandated in in vivo models, to understand its influence on cancer progression.

Anti-stromal treatment together with chemotherapy targets multiple signalling pathways in pancreatic adenocarcinoma.

Stromal targeting for pancreatic ductal adenocarcinoma (PDAC) is rapidly becoming an attractive option, due to the lack of efficacy of standard chemotherapy and increased knowledge about PDAC stroma. We postulated that the addition of stromal therapy may enhance the anti-tumour efficacy of chemotherapy. Gemcitabine and all-trans retinoic acid (ATRA) were combined in a clinically applicable regimen, to target cancer cells and pancreatic stellate cells (PSCs) respectively, in 3D organotypic culture models and genetically engineered mice (LSL-Kras(G12D) (/+) ;LSL-Trp53(R172H) (/+) ;Pdx-1-Cre: KPC mice) representing the spectrum of PDAC. In two distinct sets of organotypic models as well as KPC mice, we demonstrate a reduction in cancer cell proliferation and invasion together with enhanced cancer cell apoptosis when ATRA is combined with gemcitabine, compared to vehicle or either agent alone. Simultaneously, PSC activity (as measured by deposition of extracellular matrix proteins such as collagen and fibronectin) and PSC invasive ability were both diminished in response to combination therapy. These effects were mediated through a range of signalling cascades (Wnt, hedgehog, retinoid, and FGF) in cancer as well as stellate cells, affecting epithelial cellular functions such as epithelial-mesenchymal transition, cellular polarity, and lumen formation. At the tissue level, this resulted in enhanced tumour necrosis, increased vascularity, and diminished hypoxia. Consequently, there was an overall reduction in tumour size. The enhanced effect of stromal co-targeting (ATRA) alongside chemotherapy (gemcitabine) appears to be mediated by dampening multiple signalling cascades in the tumour-stroma cross-talk, rather than ablating stroma or targeting a single pathway. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Pancreatic stellate cells regulate blood vessel density in the stroma of pancreatic ductal adenocarcinoma.

BACKGROUND/OBJECTIVES: The vascular heterogeneity of pancreatic ductal adenocarcinoma (PDAC) has never been characterised. We analysed the heterogeneous vascular density of human PDAC along with its prognostic correlation. METHODS: Tissue Microarrays of 87 patients with different pancreatico-biliary pathologies were analysed in an automated manner (Ariol™) after CD31 staining to assess vascular density in juxta-tumoral and panstromal compartments. In vitro and ex vivo assays were carried out to assess the role of PSC. RESULTS: PDAC has a distinct vascular density and distribution of vessels compared to cholangiocarcinoma. The PDAC juxta-tumoral stroma was hypovascular and the normal adjacent rim was hypervascular compared to the panstromal compartment. These features adversely affected patient prognosis, suggesting a model for spatio-temporal PDAC evolution. Mice aortic rings and 3D organotypic cultures demonstrated pro- and anti-angiogenic signalling from activated PSC and cancer cells respectively. ATRA-induced quiescence suppressed the pro-angiogenic activity of PSC. CONCLUSION: Human PDAC has variable vascularity at microscopic level suggesting that novel stromal directed therapies would need to be determined by pathological characteristics.

Role of laparoscopy in hepatobiliary malignancies.

The many benefits of laparoscopy, including smaller incision, reduced length of hospital stay and more rapid return to normal function, have seen its popularity grow in recent years. With concurrent improvements in non-surgical cancer management the importance of accurate staging is becoming increasingly important. There are two main applications of laparoscopic surgery in managing hepato-pancreatico-biliary (HPB) malignancy: accurate staging of disease and resection. We aim to summarize the use of laparoscopy in these contexts. The role of staging laparoscopy has become routine in certain cancers, in particular T[2] staged, locally advanced gastric cancer, hilar cholangiocarcinoma and non-Hodgkin's lymphoma. For other cancers, in particular colorectal, laparoscopy has now become the gold standard management for resection such that there is no role for stand-alone staging laparoscopy. In HPB cancers, although staging laparoscopy may play a role, with ever improving radiology, its role remains controversial.