Programmed cell death ligand 1 cut-point is associated with reduced disease specific survival in resected pancreatic ductal adenocarcinoma

Machine Learning Developed a MYC Expression Feature-Based Signature for Predicting Prognosis and Chemoresistance in Pancreatic Adenocarcinoma

MYC has been identified to profoundly influence a wide range of pathologic processes in cancers. However, the prognostic value of MYC-related genes in pancreatic adenocarcinoma (PAAD) remains unclarified. Gene expression data and clinical information of PAAD patients were obtained from The Cancer Genome Atlas (TCGA) database (training set). Validation sets included GSE57495, GSE62452, and ICGC-PACA databases. LASSO regression analysis was used to develop a risk signature for survival prediction. Single-cell sequencing data from GSE154778 and CRA001160 datasets were analyzed. Functional studies were conducted using siRNA targeting RHOF and ITGB6 in PANC-1 cells. High MYC expression was found to be significantly associated with a poor prognosis in patients with PAAD. Additionally, we identified seven genes (ADGRG6, LINC00941, RHOF, SERPINB5, INSYN2B, ITGB6, and DEPDC1) that exhibited a strong correlation with both MYC expression and patient survival. They were then utilized to establish a risk model (MYCsig), which showed robust predictive ability. Furthermore, MYCsig demonstrated a positive correlation with the expression of HLA genes and immune checkpoints, as well as the chemotherapy response of PAAD. RHOF and ITGB6, expressed mainly in malignant cells, were identified as key oncogenes regulating chemosensitivity through EMT. Downregulation of RHOF and ITGB6 reduced cell proliferation and invasion in PANC-1 cells. The developed MYCsig demonstrates its potential in enhancing the management of patients with PAAD by facilitating risk assessment and predicting response to adjuvant chemotherapy. Additionally, our study identifies RHOF and ITGB6 as novel oncogenes linked to EMT and chemoresistance in PAAD.

An overview of up-and-coming immune checkpoint inhibitors for pancreatic cancer

INTRODUCTION

Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein-1 (PD-1/PD-L1) pathway as well as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) have demonstrated substantial potential in several malignancies. Pancreatic adenocarcinoma (PC) still carries a high mortality despite tremendous advances in the anti-cancer arsenal.

AREAS COVERED

In this review, we discuss completed and ongoing studies on various ICIs in PC. ICIs have not yielded significant benefits as monotherapy. However, the combination with currently utilized therapies as well as with several other newer forms of therapy has delineated encouraging results. Larger trials are currently underway to definitively characterize the utility of ICIs in the treatment algorithm of PC. ICIs are approved for cancers with mismatch repair deficiency (dMMR) or microsatellite instability-high tumors (MSI-H) as a tumor-agnostic treatment strategy usually referred to as hot tumors.

EXPERT OPINION

Studies evaluating different drugs to transform the tumor microenvironment (TME) from 'cold' to 'hot' have not shown promise in PC. There still needs to be more prospective trials evaluating the efficacy of the combination of ICIs with different therapeutic modalities in PC that can augment the immunogenic potential of those 'cold' tumors. Exploratory biomarker analysis may help us identify those subsets of PC patients who may particularly benefit from ICIs.

Recent Advancement of PD-L1 Detection Technologies and Clinical Applications in the Era of Precision Cancer Therapy

Programmed death-1 is a protein found on the surface of immune cells that can interact with its ligand, programmed death-ligand 1 (PD-L1), which is expressed on the plasma membrane, the surface of secreted cellular exosomes, in cell nuclei, or as a circulating soluble protein. This interaction can lead to immune escape in cancer patients. In clinical settings, PD-L1 plays an important role in tumor disease diagnosis, determining therapeutic effectiveness, and predicting patient prognosis. PD-L1 inhibitors are also essential components of tumor immunotherapy. Thus, the detection of PD-L1 levels is crucial, especially in the era of precision cancer therapy. In recent years, innovations have been made in traditional immunoassay methods and the development of new immunoassays for PD-L1 detection. This review aims to summarize recent research progress in tumor PD-L1 detection technology and highlight the clinical applications of PD-L1.

CXCR4-CXCL12-CXCR7 and PD-1/PD-L1 in Pancreatic Cancer: CXCL12 Predicts Survival of Radically Resected Patients

Pancreatic ductal adenocarcinoma (PDAC) is currently the most deadly cancer. Although characterized by 5-20% of neoplastic cells in the highly fibrotic stroma, immunotherapy is not a valid option in PDAC treatment. As CXCR4-CXCL12 regulates tumor invasion and T-cell access and PD-1/PD-L1 controls immune tolerance, 76 PDACs were evaluated for CXCR4-CXCL12-CXCR7 and PD-1/PD-L1 in the epithelial and stromal component. Neoplastic CXCR4 and CXCL12 discriminated PDACs for recurrence-free survival (RFS), while CXCL12 and CXCR7 discriminated patients for cancer-specific survival (CSS). Interestingly, among patients with radical resection (R0), high tumor CXCR4 clustered patients with worse RFS, high CXCL12 identified poor prognostic patients for both RFS and CSS, while stromal lymphocytic-monocytic PD-L1 associated with improved RFS and CSS. PD-1 was only sporadically expressed (<1%) in focal lymphocyte infiltrate and does not impact prognosis. In multivariate analysis, tumoral CXCL12, perineural invasion, and AJCC lymph node status were independent prognostic factors for RFS; tumoral CXCL12, AJCC Stage, and vascular invasion were independent prognostic factors for CSS. CXCL12's poor prognostic meaning was confirmed in an additional perspective-independent 13 fine-needle aspiration cytology advanced stage-PDACs. Thus, CXCR4-CXCL12 evaluation in PDAC identifies prognostic categories and could orient therapeutic approaches.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

Evaluation of MMR Status and PD-L1 Expression Using Specimens Obtained by EUS-FNB in Patients with Pancreatic Ductal Adenocarcinoma (PDAC)

Deficient DNA mismatch repair status (dMMR)/high microsatellite instability have been shown to be predictive biomarkers for immune checkpoint inhibitor drugs which block the programmed death protein-1/programmed death ligand-1 (PD-1/PD-L1) interaction between tumor cells and activated T cells. The aim of this study was to determine the prevalence of MMR status and quantification of PD-L1 expression in pancreatic endoscopic ultrasound-guided fine-needle biopsy (EUS FNB) specimens. Immunochemistry (IHC) was performed on consecutive archived treatment-naïve formalin-fixed paraffin-embedded EUS-FNB samples. The specimens were considered to have PD-L1 expression if PD-L1 was expressed in ≥1% of tumor cells and a high level of expression if ≥50%. Tumors with absent nuclear staining of DNA mismatch repair proteins (MLH1, MSH2, MSH6, or PMS2) were classified as dMMR. A total of 28 treatment-naïve patients who underwent EUS-FNB and had a final diagnosis of pancreatic ductal adenocarcinoma (PDAC) were included in the study. All the EUS-FNB samples were adequate for the evaluation of MMR and PD-L1 expression. None of the patients with PDAC included in the study had a dMMR tumor. PD-L1 expression was identified in 39% of the cohort (n = 11). Expression thresholds of ≥1%, ≥10%, and ≥50% in tumor cells were identified in 11 (39%), 4 (14%), and 1 (4%) patients, respectively. The evaluation of MMR status and PD-L1 can be successfully performed on EUS-FNB pancreatic specimens. Furthermore, MMR expression failed to show utility in recognizing immunotherapy vulnerability in pancreatic cancer; the only recommendation for testing remains for patients with heritable cancers. Meanwhile high PD-L1 expression was correlated with poor prognosis. This association may identify a subgroup of patients where immune checkpoints inhibitors could provide therapeutic benefits, spotlighting the role of EUS-FNB in the field of immune-oncology.

Comparison of programmed death ligand 1 immunostaining for pancreatic ductal adenocarcinoma between paired cytological and surgical samples

Objectives:

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis with surgery or chemotherapy. Programmed death ligand 1 expression (PD-L1) immunotherapy has been successful for treating lung and other cancers with PD-L1 expression. However, in many unresectable PDAC cases, cytological samples are the only available tissues for PD-L1 testing. The aim of this study is to retrospectively compare the expression of PD-L1 using cytological and surgical samples.

Material and Methods:

Paired formalin-fixed cell blocks and surgical samples from the same patients with confirmed diagnoses of PDAC (n = 28) were sectioned for PD-L1 immunohistochemistry. Using tumor proportion score (TPS) and combined positive score (CPS) to evaluate paired cell blocks and surgical samples, we counted and analyzed the data.

Results:

With TPS, the PD-L1 was expressed in 9/28 (32%) of PDAC surgical samples and in 9/28 (32%) of paired cytological samples. Overall, the PD-L1 expression had a correlation of 26/28 (93%). With CPS, the PD-L1 was expressed in 20/28 (71%) of PDAC surgical samples and in 16/28 (57%) of paired cytological samples. The PD-L1 expression had a correlation of 20/28 (71%) and a discrepancy of 8/28 (29%). The PD-L1 expression was significantly higher in moderately-differentiated PDAC than in well-differentiated with TPS.

Conclusion:

Cytological samples are useful for evaluating PD-L1 expression with TPS because the concordant rate was 93%. With CPS, cytological samples are limited due to the scant inflammatory cells with the concordant rate of 71%. Extensive sampling of the pancreatic tumor may improve the detection of immune cells expressing PD-L1 in cytological samples. With TPS, PD-L1 expression was significantly higher in moderate-differentiation of PDAC than in poor- and well-differentiation.

Immune checkpoint inhibition for pancreatic ductal adenocarcinoma: limitations and prospects: a systematic review

Pancreatic cancer is an extremely malignant tumor with the lowest 5-year survival rate among all tumors. Pancreatic ductal adenocarcinoma (PDAC), as the most common pathological subtype of pancreatic cancer, usually has poor therapeutic results. Immune checkpoint inhibitors (ICIs) can relieve failure of the tumor-killing effect of immune effector cells caused by immune checkpoints. Therefore, they have been used as a novel treatment for many solid tumors. However, PDAC is not sensitive to monotherapy with ICIs, which might be related to the inhibitory immune microenvironment of pancreatic cancer. Therefore, the way to improve the microenvironment has raised a heated discussion in recent years. Here, we elaborate on the relationship between different immune cellular components in this environment, list some current preclinical or clinical attempts to enhance the efficacy of ICIs by targeting the inhibitory tumor microenvironment of PDAC or in combination with other therapies. Such information offers a better understanding of the sophisticated tumor-microenvironment interactions, also providing insights on therapeutic guidance of PDAC targeting. Video Abstract.

Advancing the Care of Pancreatic Cancer Patients: Moving Beyond Just Tumour Tissue

Biobanking efforts, to establish and grow the pool of available tissue from which evidence on aetiology, therapeutic susceptibility and prognosis of various diseases, have been underway for decades. This is illustrated nowhere better than in cancer. High incidence cancers such as breast, colorectal and lung have seen massive increases in their requisite formularies that have yielded improved prognoses. These discoveries, on a very fundamental level, were made by scientists who had access to tumour tissue and associated clinical data from patient donors. As the research space for higher incidence malignancies became increasingly crowded, attention has turned towards those malignancies with lower incidence. In the same time span, technology has continued to evolve, allowing the next generation of scientists and clinicians to ask more nuanced questions. Inquiries are no longer limited to the -omics of tumour tissue but also include biomarkers of blood and excretory products, concurrent disease status and composition of the gut microbiome. The impact of these new technologies and the questions now facing researchers in low-incidence cancers will be summarized and discussed. Our experience with pancreatic ductal adenocarcinoma will be used as a model for this review.

Proteotranscriptomic classification and characterization of pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (PNENs) are biologically and clinically heterogeneous. Here, we use a multi-omics approach to uncover the molecular factors underlying this heterogeneity. Transcriptomic analysis of 84 PNEN specimens, drawn from two cohorts, is substantiated with proteomic profiling and identifies four subgroups: Proliferative, PDX1-high, Alpha cell-like and Stromal/Mesenchymal. The Proliferative subgroup, consisting of both well- and poorly differentiated specimens, is associated with inferior overall survival probability. The PDX1-high and Alpha cell-like subgroups partially resemble previously described subtypes, and we further uncover distinctive metabolism-related features in the Alpha cell-like subgroup. The Stromal/Mesenchymal subgroup exhibits molecular characteristics of YAP1/WWTR1(TAZ) activation suggestive of Hippo signaling pathway involvement in PNENs. Whole-exome sequencing reveals subgroup-enriched mutational differences, supported by activity inference analysis, and identifies hypermorphic proto-oncogene variants in 14.3% of sequenced PNENs. Our study reveals differences in cellular signaling axes that provide potential directions for PNEN patient stratification and treatment strategies.

PD-1/PD-L1 expression in pancreatic cancer and its implication in novel therapies

Pancreatic cancer is the seventh leading cause of death in developed countries and it still has a poor prognosis despite intense research in the last 20 years. Immunotherapy is a relatively new strategy in cancer treatment. The aim of immunotherapy is to block the immunosuppressive effect of tumoral cells. The PD1/PD-L1 axis has an important role in the inhibition of effector T cells and the development of regulatory T cells (Tregs). Blocking these checkpoints, and also inhibitory signals, leads to apoptosis of Tregs and increased immune response of effector T cells against tumoral antigens. Unfortunately, pancreatic cancer is generally considered to be a non-immunogenic tumor. Thus PD-1/PD-L1 inhibitors demonstrated poor results in pancreatic cancer, excepting some patients with MSI/dMMR (microsatellite instability/deficient mismatch repair). Furthermore, pancreatic cancer has a particular microenvironment with a strong desmoplastic reaction, increased interstitial fluid pressure, hypoxic conditions, and acidic extracellular pH, which promote tumorigenesis and progression of the tumor. Mismatch repair deficiency (dMMR) is correlated with a high level of mutation-associated neoantigens, most recognized by immune cells which could predict a favorable response to anti-PD-1/PD-L1 therapy. PD-1/PD-L1 molecules could be also found as soluble forms (sPD-1, sPD-L1). These molecules have a potential role in the prognosis and treatment of pancreatic cancer.

Targeting Pin1 renders pancreatic cancer eradicable by synergizing with immunochemotherapy

Pancreatic ductal adenocarcinoma (PDAC) is characterized by notorious resistance to current therapies attributed to inherent tumor heterogeneity and highly desmoplastic and immunosuppressive tumor microenvironment (TME). Unique proline isomerase Pin1 regulates multiple cancer pathways, but its role in the TME and cancer immunotherapy is unknown. Here, we find that Pin1 is overexpressed both in cancer cells and cancer-associated fibroblasts (CAFs) and correlates with poor survival in PDAC patients. Targeting Pin1 using clinically available drugs induces complete elimination or sustained remissions of aggressive PDAC by synergizing with anti-PD-1 and gemcitabine in diverse model systems. Mechanistically, Pin1 drives the desmoplastic and immunosuppressive TME by acting on CAFs and induces lysosomal degradation of the PD-1 ligand PD-L1 and the gemcitabine transporter ENT1 in cancer cells, besides activating multiple cancer pathways. Thus, Pin1 inhibition simultaneously blocks multiple cancer pathways, disrupts the desmoplastic and immunosuppressive TME, and upregulates PD-L1 and ENT1, rendering PDAC eradicable by immunochemotherapy.

Gemcitabine Plus Nab-Paclitaxel Induces PD-L1 mRNA Expression in Plasma-Derived Microvesicles in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a non-immunogenic tumor poorly responsive to immune checkpoint inhibitors. This study investigates the effect of 5-fluorouracil (5-FU), irinotecan, and oxaliplatin (FOLFIRINOX), and gemcitabine plus nab-paclitaxel (GEMnPAC) regimens on PD-L1 mRNA expression in plasma-derived microvesicles (MVs) in 50 PDAC patients. Plasma was collected before starting chemotherapy and after 3 months of treatment. mRNA was extracted from MVs, and PD-L1 expression was measured by digital droplet PCR. Twenty-eight patients were PD-L1 positive in MVs at baseline, of which 18 were in the GEMnPAC cohort and 10 in the FOLFIRINOX one. The amount of PD-L1 expression in MVs increased from baseline to 3 months of treatment in patients receiving GEMnPAC (median value 0.002 vs. 0.005; p = 0.01) compared to those treated with FOLFIRINOX (median 0.003 vs. 0.004; p = 0.97). The increase in PD-L1 mRNA expression in MVs was not related to tumor response (PR + SD: p = 0.08; PD: p = 0.28). Our findings demonstrate that GEMnPAC can increase PD-L1 mRNA expression in patient-derived circulating MVs, providing a rationale for testing the efficacy of this regimen in sequential or simultaneous combinations with immunotherapy in PDAC patients.

Levels of Circulating PD-L1 Are Decreased in Patients with Resectable Cholangiocarcinoma

Tumor resection represents the only curative treatment option for patients with biliary tract cancers (BTCs), including intrahepatic cholangiocarcinoma (CCA), perihilar and extrahepatic CCA and gallbladder cancer. However, many patients develop early tumor recurrence and are unlikely to benefit from surgery. Therefore, markers to identify ideal surgical candidates are urgently needed. Circulating programmed cell death 1 ligand 1 (PD-L1) has recently been associated with different malignancies, including pancreatic cancer which closely resembles BTC in terms of patients’ prognosis and tumor biology. Here, we aim at evaluating a potential role of circulating PD-L1 as a novel biomarker for resectable BTC. Methods: Serum levels of PD-L1 were analyzed by ELISA in 73 BTC patients and 42 healthy controls. Results: Circulating levels of preoperative PD-L1 were significantly lower in patients with BTC compared to controls. Patients with low PD-L1 levels displayed a strong trend towards an impaired prognosis, and circulating PD-L1 was negatively correlated with experimental markers of promalignant tumor characteristics such as CCL1, CCL21, CCL25 and CCL26. For 37 out of 73 patients, postoperative PD-L1 levels were available. Interestingly, after tumor resection, circulating PD-L1 raised to almost normal levels. Notably, patients with further decreasing PD-L1 concentrations after surgery showed a trend towards an impaired postoperative outcome. Conclusion: Circulating PD-L1 levels were decreased in patients with resectable BTC. Lack of normalization of PD-L1 levels after surgery might identify patients at high risk for tumor recurrence or adverse outcome.

Immune cell infiltrates as prognostic biomarkers in pancreatic ductal adenocarcinoma: a systematic review and meta-analysis

Immune cell infiltration has been identified as a prognostic biomarker in several cancers. However, no immune based biomarker has yet been validated for use in pancreatic ductal adenocarcinoma (PDAC). We undertook a systematic review and meta-analysis of immune cell infiltration, measured by immunohistochemistry (IHC), as a prognostic biomarker in PDAC. All other IHC prognostic biomarkers in PDAC were also summarised. MEDLINE, EMBASE and Web of Science were searched between 1998 and 2018. Studies investigating IHC biomarkers and prognosis in PDAC were included. REMARK score and Newcastle-Ottawa scale were used for qualitative analysis. Random-effects meta-analyses were used to pool results, where possible. Twenty-six articles studied immune cell infiltration IHC biomarkers and PDAC prognosis. Meta-analysis found high infiltration with CD4 (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.51-0.83.) and CD8 (HR = 0.68, 95% CI = 0.55-0.84.) T-lymphocytes associated with better disease-free survival. Reduced overall survival was associated with high CD163 (HR = 1.62, 95% CI = 1.03-2.56). Infiltration of CD3, CD20, FoxP3 and CD68 cells, and PD-L1 expression was not prognostic. In total, 708 prognostic biomarkers were identified in 1101 studies. In summary, high CD4 and CD8 infiltration are associated with better disease-free survival in PDAC. Increased CD163 is adversely prognostic. Despite the publication of 708 IHC prognostic biomarkers in PDAC, none has been validated for clinical use. Further research should focus on reproducibility of prognostic biomarkers in PDAC in order to achieve this.

Topographical Distribution and Spatial Interactions of Innate and Semi-Innate Immune Cells in Pancreatic and Other Periampullary Adenocarcinoma

Background

The clinical management of pancreatic and other periampullary neoplasms remains challenging. In contrast to other cancer types, immunotherapies are largely ineffective, and the reason for the deprived immune response and the immune inhibiting cellular composition is only fragmentarily understood. The aim of this study was to comprehensively map the abundance, topographic distribution and spatial interaction of innate and innate-like immune cells in the tumor microenvironment of periampullary adenocarcinoma.

Methods

Multiplexed immunofluorescent imaging was performed on tissue microarrays with tumors from a consecutive cohort of 175 patients with resected periampullary adenocarcinoma. To obtain a detailed spatial analysis of immune cell infiltration, two multiplex immune panels including antibodies against CD3, NKp46, CD56, CD68, CD163 and CD1a, CD208, CD123, CD15, CD68 and pan-cytokeratin were applied.

Results

The infiltration of natural killer (NK) and NK-like T (NKT) cells was lower in malignant compared to benign tissue. NKT cells were more abundant in intestinal type compared to pancreatobiliary type tumors, and were associated with more favorable clinicopathological features and a prolonged survival. The interaction of NKp46⁺ NKT cells with macrophages was also associated with a prolonged survival.

Conclusions

This study provides a comprehensive map of the innate immune landscape in periampullary adenocarcinoma. NK cells, and even more so NKT cells, are revealed to be central players in the local immune response in a clinically relevant context.

Immuno-Surgical Management of Pancreatic Cancer with Analysis of Cancer Exosomes

Exosomes (EXs), a type of extracellular vesicles secreted from various cells and especially cancer cells, mesenchymal cells, macrophages and other cells in the tumor microenvironment (TME), are involved in biologically malignant behaviors of cancers. Recent studies have revealed that EXs contain microRNAs on their inside and express proteins and glycolipids on their outsides, every component of which plays a role in the transmission of genetic and/or epigenetic information in cell-to-cell communications. It is also known that miRNAs are involved in the signal transduction. Thus, EXs may be useful for monitoring the TME of tumor tissues and the invasion and metastasis, processes that are associated with patient survival. Because several solid tumors secrete immune checkpoint proteins, including programmed cell death-ligand 1, the EX-mediated mechanisms are suggested to be potent targets for monitoring patients. Therefore, a companion therapeutic approach against cancer metastasis to distant organs is proposed when surgical removal of the primary tumor is performed. However, EXs and immune checkpoint mechanisms in pancreatic cancer are not fully understood, we provide an update on the recent advances in this field and evidence that EXs will be useful for maximizing patient benefit in precision medicine.

Quantitative, qualitative and spatial analysis of lymphocyte infiltration in periampullary and pancreatic adenocarcinoma

Immunotherapeutic modalities are currently revolutionizing cancer treatment. In pancreatic cancer, however, early clinical trials have been disappointing. The optimization of immunotherapeutic strategies requires better understanding of the inflammatory tumor microenvironment. Therefore, the aim of our study was to perform a detailed in situ description of lymphocyte infiltration patterns in resected pancreatic and other periampullary cancers. Multiplexed immunofluorescence imaging was applied to tissue microarrays with tumors from a cohort of 175 patients with resected periampullary adenocarcinoma. A panel of immune cell markers including CD4, CD8α, FoxP3, CD20, CD45RO and pan-cytokeratin was applied to allow for simultaneous spatial analysis of multiple lymphocyte populations. The majority of lymphocyte populations were significantly more abundant in intestinal (I-type) compared to pancreatobiliary (PB-type) tumors. Hierarchical cluster analysis revealed several immune cell signatures of potential clinical relevance. Notably, in the stromal compartment of PB-type tumors, high infiltration of B cells, CD8α⁺ CD45RO⁺ and single-positive CD4⁺ T cells, but low levels of FoxP3⁺ CD45RO^high and single-positive CD8α⁺ T cells were associated with improved overall survival (OS). The study also defined prognostic relevant topographical patterns of lymphocytic infiltration, in particular proximity of CD8α⁺ cells to cancer cells. Moreover, the presence of lymphocytes with potential T-helper capacities (CD4⁺ ) in the nearest vicinity to CD8α⁺ cells was associated with a prolonged OS. Our data demonstrate that the composition and clinical impact of immune infiltrates in periampullary adenocarcinoma differ by morphological type as well as localization. Furthermore, spatial in situ analysis identified potential immunological mechanisms of prognostic significance.

A systemic inflammation response index (SIRI) correlates with survival and predicts oncological outcome for mFOLFIRINOX therapy in metastatic pancreatic cancer

OBJECTIVES

Systemic inflammatory response and survival has not been evaluated as a predictive factor of chemotherapy in metastatic pancreatic cancer. The aim of this study was to evaluate the prognostic and predictive value of a baseline Systemic Inflammation Response Index (SIRI) in metastatic pancreatic cancer.

METHODS

Retrospective study of 164 metastatic pancreatic cancer patients. Associations between overall survival (OS), progression free survival (PFS), chemotherapy and SIRI were analyzed. SIRI is defined by neutrophil x monocyte/lymphocyte 10⁹/L.

RESULTS

Median age 66 years. 22 (13%) received mFOLFIRINOX, 59 (36%) gemcitabine + nab-paclitaxel, 40 (24%) gemcitabine, 13 (8%) other regimens and 30 (18%) had not received treatment. Patients with SIRI<2.3 × 10⁹/L showed a statistically significant improvement in OS compared to SIRI≥2.3 × 10⁹/L [16 months versus 4.8 months, Hazard Ratio (HR) 2.87, Confidence Interval (CI) 95% 2.02-4.07, p < 0.0001] that was confirmed in multivariate analysis. In addition, patients with SIRI<2.3 × 10⁹ showed a longer PFS (12 versus 6 months, HR 1.92, IC 95% 1.314-2.800, P = 0.001). Furthermore, we observed that patients with SIRI ≥2.3 × 10⁹/L were more likely to benefit from mFOLFIRINOX therapy. Patients with an elevated SIRI treated with mFOLFIRINOX versus gemcitabine plus nab-paclitaxel and gemcitabine showed a clinically and statistically significant difference in median OS of 17 months compared to 6 and 4 months respectively (p < 0.001). Conversely, the difference was not clinically significant in the SIRI<2.3 × 10⁹/L subgroup: 15.9 months versus 16.5 and 16, respectively.

CONCLUSION

An elevated SIRI (≥2.3 × 10⁹/L) was an independent prognostic factor for patients with metastatic pancreatic cancer, warranting prospective evaluation.

Spatiotemporal Changes in Checkpoint Molecule Expression

Immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 blockade, have led to therapeutic breakthrough in patients with advanced malignancy, covering the lung, breast, gastrointestinal, head and neck, urinary system, lymphoma, and solid tumor harboring MSI/dMMR. In certain cancer types, the expression level of immune checkpoint molecule will be required if the immune-based approaches are considered, especially the PD-L1 expression. However, in other types, survival benefit has been proven regardless of PD-L1 expression. It raises a question of how to select patients for immune therapy and whether the expression of immune checkpoint molecules will be optimal biomarkers. Before answering this question, a comprehensive map for the expression of immune checkpoint molecules is needed. In this chapter, we describe our current knowledge on the spatiotemporal changes in the expression of checkpoint molecules. We discuss the different frequencies of expression depending on tumor types and stages, the different patterns between primary and metastatic tumors, as well as the change of expression before and after treatment. The expression of PD-L1 has been most studied, but the threshold that separate "positive" and "negative" PD-L1 expressions and the consistency of testing platform remain under debate. Better understanding on the tumor microenvironment and expression of checkpoint molecules will help to identify patients who will benefit from checkpoint blockade therapy.

Durvalumab With or Without Tremelimumab for Patients With Metastatic Pancreatic Ductal Adenocarcinoma: A Phase 2 Randomized Clinical Trial

Importance

New therapeutic options for patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) are needed. This study evaluated dual checkpoint combination therapy in patients with mPDAC.

Objective

To evaluate the safety and efficacy of the anti-PD-L1 (programmed death-ligand 1) antibody using either durvalumab monotherapy or in combination with the anticytotoxic T-lymphocyte antigen 4 antibody using durvalumab plus tremelimumab therapy in patients with mPDAC.

Design, Setting, and Participants

Part A of this multicenter, 2-part, phase 2 randomized clinical trial was a lead-in safety, open-label study with planned expansion to part B pending an efficacy signal from part A. Between November 26, 2015, and March 23, 2017, 65 patients with mPDAC who had previously received only 1 first-line fluorouracil-based or gemcitabine-based treatment were enrolled at 21 sites in 6 countries. Efficacy analysis included the intent-to-treat population; safety analysis included patients who received at least 1 dose of study treatment and for whom any postdose data were available.

Interventions

Patients received durvalumab (1500 mg every 4 weeks) plus tremelimumab (75 mg every 4 weeks) combination therapy for 4 cycles followed by durvalumab therapy (1500 mg every 4 weeks) or durvalumab monotherapy (1500 mg every 4 weeks) for up to 12 months or until the onset of progressive disease or unacceptable toxic effects.

Main Outcomes and Measures

Safety and efficacy were measured by objective response rate, which was used to determine study expansion to part B. The threshold for expansion was an objective response rate of 10% for either treatment arm.

Results

Among 65 randomized patients, 34 (52%) were men and median age was 61 (95% CI, 37-81) years. Grade 3 or higher treatment-related adverse events occurred in 7 of 32 patients (22%) receiving combination therapy and in 2 of 32 patients (6%) receiving monotherapy; 1 patient randomized to the monotherapy arm did not receive treatment owing to worsened disease. Fatigue, diarrhea, and pruritus were the most common adverse events in both arms. Overall, 4 of 64 patients (6%) discontinued treatment owing to treatment-related adverse events. Objective response rate was 3.1% (95% CI, 0.08-16.22) for patients receiving combination therapy and 0% (95% CI, 0.00-10.58) for patients receiving monotherapy. Low patient numbers limited observation of the associations between treatment response and PD-L1 expression or microsatellite instability status.

Conclusion and Relevance

Treatment was well tolerated, and the efficacy of durvalumab plus tremelimumab therapy and durvalumab monotherapy reflected a population of patients with mPDAC who had poor prognoses and rapidly progressing disease. Patients were not enrolled in part B because the threshold for efficacy was not met in part A.

Trial Registration

ClinicalTrials.gov identifier: NCT02558894.

Prognostic implications of soluble programmed death-ligand 1 and its dynamics during chemotherapy in unresectable pancreatic cancer

In pancreatic cancer, acquiring a sufficient amount of tumor tissue is an obstacle. The soluble form of PD-L1 (sPD-L1) may have immunosuppressive activity. Here, we evaluated the prognostic implications of sPD-L1 in unresectable pancreatic cancer. We prospectively enrolled 60 patients treated with first-line FOLFIRINOX chemotherapy. We collected blood samples at diagnosis, first response assessment and disease progression. Serum sPD-L1 levels were measured using enzyme-linked immunosorbent assays. The median sPD-L1 level was 1.7 ng/mL (range, 0.4-5.7 ng/mL). Patients with low sPD-L1 level (<4.6 ng/mL) at diagnosis showed better overall survival (OS) than those with high sPD-L1 level (P = 0.015). Multivariate analysis identified sPD-L1 and the neutrophil-to-lymphocyte ratio as independent prognostic factors for OS. During chemotherapy, more patients achieved complete response (CR)/partial response (PR) as their best response when sPD-L1 was decreased at the first response assessment (P = 0.038). In the patients who achieved CR/PR as their best response, sPD-L1 was significantly higher at the time of disease progression than at the first response assessment (P = 0.025). In conclusion, the sPD-L1 level at diagnosis exhibits a prognostic value in pancreatic cancer. Furthermore, sPD-L1 dynamics correlate with disease course and could be used to understand various changes in the tumor microenvironment during chemotherapy.

[18F]FMISO PET/CT as a preoperative prognostic factor in patients with pancreatic cancer

Background

While [¹⁸F]fluoromisonidazole (FMISO), a representative PET tracer to detect hypoxia, is reported to be able to prospect the prognosis after treatment for various types of cancers, the relation is unclear for pancreatic cancer. The aim of this study is to assess the feasibility of [¹⁸F]FMISO PET/CT as a preoperative prognostic factor in patients with pancreatic cancer.

Methods

Patients with pancreatic cancer who had been initially planned for surgery received [¹⁸F]FMISO PET/CT. Peak standardized uptake value (SUV) of the pancreatic tumor was divided by SUVpeak of the aorta, and tumor blood ratio using SUVpeak (TBRpeak) was calculated. After preoperative examination, surgeons finally decided the operability of the patients. TBRpeak was compared with hypoxia-inducible factor (HIF)-1α immunohistochemistry when the tissues were available. Furthermore, correlation of TBRpeak with the recurrence-free survival and the overall survival were evaluated by Kaplan-Meyer methods.

Results

We analyzed 25 patients with pancreatic adenocarcinoma (11 women and 14 men, median age, 73 years; range, 58–81 years), and observed for 39–1101 days (median, 369 days). Nine cases (36.0%) were identified as visually positive of pancreatic cancer on [¹⁸F]FMISO PET/CT images. TBRpeak of the negative cases was significantly lower than that of the positive cases (median 1.08, interquartile range (IQR) 1.02–1.15 vs median 1.50, IQR 1.25–1.73, p < 0.001), and the cutoff TBRpeak was calculated as 1.24. Five patients were finally considered inoperable. There was no significant difference in TBRpeak of inoperable and operable patients (median 1.48, IQR 1.06–1.98 vs median 1.12, IQR 1.05–1.21, p = 0.10). There was no significant difference between TBRpeak and HIF-1α expression (p = 0.22). The patients were dichotomized by the TBRpeak cutoff, and the higher group showed significantly shorter recurrence-free survival than the other (median 218 vs 441 days, p = 0.002). As for overall survival of 20 cases of operated patients, the higher TBRpeak group showed significantly shorter overall survival than the other (median survival, 415 vs > 1000 days, p = 0.04).

Conclusions

[¹⁸F]FMISO PET/CT has the possibility to be a preoperative prognostic factor in patients with pancreatic cancer.

Electronic supplementary material

The online version of this article (10.1186/s13550-019-0507-8) contains supplementary material, which is available to authorized users.

HDAC3 modulates cancer immunity via increasing PD-L1 expression in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the second leading cause of cancer-related deaths worldwide. Despite immune checkpoints based immunotherapy highlights a new therapeutic strategy and achieves a remarkable therapeutic effect in various types of malignant tumors. Pancreatic cancer is one of the non-immunogenic cancers and is resistant to immunotherapy. Programmed death ligand 1 (PD-L1) is expressed on the surface of tumor cells and its level is a key determinant of the checkpoint immunotherapy efficacy. Here, we reported that the specific inhibitor of histone deacetylase 3 (HDAC3) decreased the protein and mRNA level of PD-L1 in pancreatic cancer cells. Furthermore, we showed that HDAC3 was critical for PD-L1 regulation and positively correlated with PD-L1 in PDAC patient specimens. Finally, we demonstrated that HDAC3/signal transducer and activator of transcription 3 (STAT3) pathway transcriptionally regulated PD-L1 expression. Collectively, our data contributes to a better understanding of the function of HDAC3 in cancer immunity and the regulatory mechanism of PD-L1. More importantly, these data suggest that the HDAC3 inhibitors might be used to improve immunotherapy in pancreatic cancer.

PD-L1 expression in pancreatic adenosquamous carcinoma: PD-L1 expression is limited to the squamous component

AIM

We examined the programmed death-ligand 1 (PD-L1) expression in surgically resected pancreatic adenosquamous carcinoma (PASC) samples. Furthermore, the detection rate was also assessed using biopsy cases obtained from endoscopic ultrasound-guided fine needle aspiration (EUS-FNA).

METHODS

Fifteen cases of PASC (six resected and nine EUS-FNA biopsied) from the Kurume University Hospital between 2009 and 2016 were used for the evaluation of PD-L1 expression. As a control group, 34 cases of pancreatic ductal adenocarcinomas (PDACs) were selected. To compare　the positivity and intensity of PD-L1, two types of clones (SP263, E1L3N) were examined for immunostaining. Only the membrane expression of PD-L1 was regarded as positive. The PD-L1 expressions in the squamous cell carcinoma component (SCc), adenocarcinoma component (ACc), and immune cells were assessed separately. The ratio of PD-L1 expression was calculated by counting the positive tumor cells, and tumor proportion score (TPS) was applied (TPS; Null < 1%, low expression; 1 ≤ TPS ≤ 49% and high expression; ≥ 50%).

RESULTS

PD-L1 expression was observed in five surgical PASC samples (83%). This shows that SCc presented a high expression in these cases. However, the overall TPS indicated a low expression. In contrast, only one case (3%) was positive for PD-L1 in PDACs, and the TPS indicated a low expression. No differences in PD-L1 expression were observed between the two clones, SP263 and E1L3N. High PD-L1 expression in the EUS-FNA sample was found in only one case (11%).

DISCUSSION

Although assessment using the tumor cells of PASC samples obtained from EUS-FNA was difficult, this study suggests the selective expression of PD-L1 in the SCc of PASC. Furthermore, it was considered that immune checkpoint inhibitors could provide therapeutic effects selectively on the SCc for the entire range of TPSs, though the PD-L1 expression was low.

The immune checkpoint, HVEM may contribute to immune escape in non-small cell lung cancer lacking PD-L1 expression

BACKGROUND

Herpes Virus Entry Mediator (HVEM) is an important immune checkpoint in cancer recognition. HVEM expressed on tumor cell membranes activates immune cell signaling pathways leading to either inhibition of activity (B- and T-lymphocyte attenuator, BTLA) or activation of immune activity (LIGHT). The aim of this study is to investigate the prevalence of HVEM expression and its association with PDL1 expression in NSCLC.

METHODS

A TMA of 527 resected NSCLC samples and 56 NSCLC cell lines were evaluated for HVEM and PD-L1 expression. The IHC assay for HVEM was optimized on the Dako Link48 autostainer using a polyclonal antibody from R&D Systems(AF356). PD-L1 IHC was performed on the Dako Link48 autostainer using the PD-L1 28-8 pharmDx kit. Scoring HVEM employed the H-score system while for PD-L1 the tumor proportion score (TPS) was used.

RESULTS

HVEM expression in the NSCLC resected samples and cell lines revealed a positive H-score more than 1 was 18.6% (77/415) and 48.2% (27/56) respectively. HVEM expression was significantly higher in patients with lymph node N2 metastasis (25.5% vs 7.9% vs 17.5%, p = 0.046) when comparing with N1 or no lymph node metastasis, and was marginally significantly higher in patients with stage III/IV disease (24.5% vs 16.4%, p = 0.059). Subgroup analysis showed that HVEM (median 45 vs 36 months, p = 0.706) and PD-L1 expression (median 45 vs 48 months, p = 0.178) status was not predictive of overall survival. HVEM was found to have a significant negative correlation with PD-L1 expression (r=-0.274, p < 0.001) in patients with NSCLC and also a weak negative correlation in NSCLC cell lines (r=-0.162, p = 0.352).

CONCLUSION

HVEM was found to be overexpressed in NSCLC patients of N2 lymph node metastasis or later stage and has a negative co-relationship with PD-L1 expression. HVEM was not prognostic for NSCLC patients.

PD-1, PD-L1, and CD163 in pancreatic undifferentiated carcinoma with osteoclast-like giant cells: expression patterns and clinical implications

Undifferentiated carcinoma with osteoclast-like giant cells (UCOGC), a variant of pancreatic ductal adenocarcinoma (PDAC), has a striking genetic similarity to PDAC but a significantly improved overall survival. We hypothesize that this difference could be due to the immune response to the tumor, and as such, we investigated the expression of PD-1, PD-L1, and CD163 in a series of UCOGC. To this aim, 27 pancreatic UCOGCs (11 pure and 16 PDAC-associated), 5 extrapancreatic tumors with osteoclast-like giant cells and 10 pancreatic anaplastic carcinomas were immunostained using antibodies against PD-1, PD-L1, and CD163. In pancreatic UCOGCs, PD-L1 was expressed in neoplastic cells of 17 (63%) of 27 cases, more often in cases with an associated PDAC (P = .04). Expression of PD-L1 was associated with poor prognosis, confirmed by multivariate analysis: patients with PD-L1-positive UCOGCs had a risk of all-cause mortality that was 3 times higher than did patients with PD-L1-negative UCOGCs (hazard ratio, 3.397; 95% confidence interval, 1.023-18.375; P = .034). PD-L1 expression on tumor cells was also associated with aberrant P53 expression (P = .035). PD-1 was expressed on rare lymphocytes in 12 UCOGCs (44.4%), mainly located at the tumor periphery. CD163 was expressed on histiocytes, with a diffuse and strong staining pattern in all UCOGCs. Extrapancreatic tumors with osteoclast-like giant cells showed very similar staining patterns for the same proteins. Anaplastic carcinomas have some similarities to UCOGCs, but PD-L1 has no prognostic roles. Our results may have important implications for immunotherapeutic strategies in UCOGCs; these tumors may also represent a model for future therapeutic approaches against PDAC.

Expression of STING and PD-L1 in colorectal cancer and their correlation with clinical prognosis

OBJECTIVE

To investigate the expression of PD-L1 and STING in colorectal cancer and analyze their correlation with disease prognosis.

METHODS

The colorectal tissue chip was taken as the research object. Immunohistochemical methods were used to detect expression of PD-L1 and STING of 87 cases of colorectal cancer tissue and corresponding adjacent tissue in the tissue chip. Chi-square test or Fisher's test were used to analyze the relationship of expression of PD-L1 and STING and with the clinical pathological features. Kaplan-Meier curves were used to analyze the relationship between expression of PD-L1 and STING and the prognosis of colorectal cancer.

RESULTS

The positive expression rate of PD-L1 in 87 cases of colorectal cancer tissue and corresponding adjacent tissue was 79.3% and 42.5% respectively, and the difference was significant (P < 0.05). The positive expression rate of PD-L1 in colorectal carcinoma tissues was not related with age, gender, tumor size, differentiation, TNM clinical stage, or depth of invasion (P > 0.05). The positive expression rate of STING in 87 cases colorectal cancer tissues and corresponding adjacent tissue was 9.2% and 40.2% respectively and the difference was significant (P < 0.05). The positive expression rate of STING in colorectal carcinoma tissue was correlated with gender, age, and differentiation (P < 0.05), but not associated with tumor size, depth of invasion, and TNM clinical stage (P > 0.05). The expression rate of PD-L1 was related to the prognosis of colorectal cancer (P=0.018). The expression rate of STING was not correlated with prognosis of colorectal cancer (P=0.784). In four independent groups (PD-L1⁺STING⁺ group, PD-L1^-STING^- group, PD-L1^-STING⁺ group, PD-L1⁺STING^- group), there were significant differences in 5-year survival (P=0.047 < 0.05), the 5-year survival rate of the PD-L1^-STING⁺ group was significantly higher than that of the other three groups. In the STING positive group, the PD-L1⁺STING⁺ group had a worse prognosis than the PD-L1^-STING⁺ group. In the STING negative group, the PD-L1^-STING^-group had a higher survival rate than the PD-L1⁺STING^- group.

CONCLUSION

PD-L1 might promote the occurrence of disease and STING might play an important role in anti-tumor immunity. PD-L1 was related with the prognosis of patients with colorectal cancer but the expression of STING was not obviously associated with the prognosis. Survival rates of patients with colorectal cancer were higher in patients with PD-L1 negative expression or STING positive expression. When PD-L1 expression was negative and STING expression was positive, the 5-year survival rate of patients with colorectal cancer was highest.