The Clinicopathological and Prognostic Value of PD-L1 Expression in Cholangiocarcinoma: A Meta-Analysis

Epigenetic silencing of miR-125a-3p promotes the progress of human cholangiocarcinoma via increasing CAC1 expression

We aimed to investigate the dysregulation of the microRNAs(miRNAs) in cholangiocarcinoma (CCA), including its impact on the homeostasis of the transcriptome and cellular behavior. MiRNAs serve as potent epigenetic regulators of transcriptional output, targeting various signaling pathways. This study aimed to investigate the expression level, epigenetic mechanism and function of miR-125a-3 in CCA. The study data showed that the expression level of miR125a-3p was decreased in CCA tissue samples and cell lines, and it was closely related to lymph node metastasis, tissue differentiation and TNM stage. The data demonstrate a strong association between decreased miR-125a-3p expression and poorer prognosis in cholangiocarcinoma patients. miR-125a-3p acts as a tumor suppressor by inhibiting the viability, migration and invasion of CCA cells. There are CpG islands in the promoter region of miR-125a-3p gene, and the methylation of the promoter region of miR-125a-3p gene leads to the transcriptional repression of miR-125a-3p. In addition, miR125a-3p can target and regulate CAC1 mRNA and protein expression in the downstream mechanism, and the high expression of CAC1 can promote the proliferation, migration and invasion of cholangiocarcinoma cells. These data demonstrate that miR-125a-3p promoter methylation leads to silencing of its expression. Mechanically, miR-125a-3p acts as a tumor suppressor and participates in the occurrence and development of CCA through targeting CAC1 gene expression. Therefore, miR-125a-3p may serve as a new target for the diagnosis, prognostic assessment or molecular therapy of CCA.

Unveiling the promise of PD1/PD-L1: A new dawn in immunotherapy for cholangiocarcinoma

Cholangiocarcinoma (CCA), a rare yet notably aggressive cancer, has experienced a surge in incidence in recent years. Presently, surgical resection remains the most effective curative strategy for CCA. Nevertheless, a majority of patients with CCA are ineligible for surgical removal at the time of diagnosis. For advanced stages of CCA, the combination of gemcitabine and cisplatin is established as the standard chemotherapy regimen. Despite this, treatment efficacy is often hindered by the development of resistance. In recent times, immune checkpoint inhibitors, particularly those that block programmed death 1 and its ligand (PD1/PD-L1), have emerged as promising strategies against a variety of cancers and are being increasingly integrated into the therapeutic landscape of CCA. A growing body of research supports that the use of PD1/PD-L1 monoclonal antibodies in conjunction with chemotherapy may significantly improve patient outcomes. This article seeks to meticulously review the latest studies on PD1/PD-L1 involvement in CCA, delving into their expression profiles, prognostic significance, contribution to oncogenic processes, and their potential clinical utility.

The Expression of Programmed Death-Ligand 1 on Immune Cells Is Related to a Better Prognosis in Biliary Tract Cancer

Background/Aims

Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis.

Methods

PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC.

Results

Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018).

Conclusions

PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.

Immune checkpoint inhibitors in cholangiocarcinoma

Cholangiocarcinoma is an epithelial malignancy originating in the biliary tracts and frequently recurs even with surgical resection. Unresectable disease has a 5-year overall survival of less than 10%. Given this poor prognosis, additional therapies are urgently needed. Chemotherapy has been the mainstay of treatment for many years. However, with the incorporation of immunotherapy into the treatment of other malignancies, there has been a great deal of interest in immunotherapy for biliary cancers. Recently, durvalumab was approved in combination with gemcitabine and cisplatin for the treatment of unresectable cholangiocarcinoma in the first-line setting. However, predicting which patients may respond to immunotherapy remains a challenge due to the lack of a reliable biomarker.

PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor for patients with intrahepatic cholangiocarcinoma

Cholangiocarcinoma, the second most common liver malignancy, after hepatocarcinoma is highly aggressive and usually diagnosed in advanced cases. In the era of personalized medicine, targeted therapy protocols are limited for cholangiocarcinoma and the only potential curative treatment, surgical resection, is seldom applicable.This retrospective study included all cases with pathology-confirmed intrahepatic cholangiocarcinoma admitted in a tertiary healthcare facility during a 10-year timeframe. Clinical information, laboratory values, imaging studies, and survival data were retrieved, and PD-L1 immunostaining was performed on representative pathology slides, for each case. From the total of 136 included cases (49 surgical resections and 87 liver biopsies), 38.97% showed PD-L1 positivity on tumoral cells, 34.8% on tumor infiltrating immune cells, 10.11% on epithelial cells within the peritumoral area and 15.95% on immune cells from the peritumoral area. Overall survival was significantly higher in the first two scenarios. However, after adjusting for age, tumor number, tumor size, and tumor differentiation in a multivariate analysis, only PD-L1 positivity on tumor infiltrating immune cells remained a favorable prognostic for survival. High immune cell counts also correlated with increased overall survival.Our study demonstrated that PD-1/PD-L1 checkpoint pathway in the microenvironment of intrahepatic cholangiocarcinoma bears prognostic significance. PD-L1 expression on immune cells, in both resection and biopsy specimens, might be a strong independent predictor for a favorable outcome.

Advances in molecular and cell therapy for immunotherapy of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly malignant tumor of the hepatobiliary system that has failed to respond to many traditional therapies to a certain extent, including surgery, chemotherapy and radiotherapy. In recent years, the new therapeutic schemes based on immunology have fundamentally changed the systemic treatment of various malignant tumors to a certain extent. In view of the immunogenicity of CCA, during the occurrence and development of CCA, some immunosuppressive substances are released from cells and immunosuppressive microenvironment is formed to promote the escape immune response of its own cells, thus enhancing the malignancy of the tumor and reducing the sensitivity of the tumor to drugs. Some immunotherapy regimens for cholangiocarcinoma have produced good clinical effects. Immunotherapy has more precise characteristics and less adverse reactions compared with traditional treatment approaches. However, due to the unique immune characteristics of CCA, some patients with CCA may not benefit in the long term or not benefit at all after current immunotherapy. At present, the immunotherapy of CCA that have been clinically studied mainly include molecular therapy and cell therapy. In this article, we generalized and summarized the current status of immunotherapy strategies including molecular therapy and cell therapy in CCA in clinical studies, and we outlined our understanding of how to enhance the clinical application of these immunotherapy strategies.

Prognostic roles of leptin-signaling proteins, PD-L1, and tumor-infiltrating lymphocytes in surgically-resected biliary tract cancers

BACKGROUND

Biliary tract cancers are rare, with a poor patient prognosis. Leptin and programmed death-ligand 1 (PD-L1) influence CD8⁺ and forkhead box P3 (FOXP3)⁺ lymphocytes, and thus, cancer cell growth. We aimed to define the prognostic implications of these variables and the clinicopathological features of biliary tract cancers.

METHODS

Immunohistochemistry for leptin signaling-related proteins (leptin, leptin receptor, pSTAT3, extracellular-regulated kinase, mammalian target of rapamycin), PD-L1, CD8, and FOXP3 and in situ hybridization for Epstein-Barr virus-encoded small RNAs were performed in 147 cases of surgically-resected biliary tract cancers.

RESULTS

Immune cell PD-L1-positivity, tumor size < 3 cm, adjuvant chemotherapy, no recurrence, and early-stage tumors were correlated with better 5-year survival in the tumoral PD-L1^(-) and leptin^(-) subgroups, and extrahepatic cholangiocarcinoma through multivariate analysis (all p < 0.05). Immune cell PD-L1 and adjuvant chemotherapy lost its prognostic significance in the tumoral PD-L1⁺ and leptin⁺ subgroups.

CONCLUSIONS

The prognostic implication of the variables may depend upon tumoral protein expression and the anatomical site. Immune cell PD-L1-positivity and the administration of adjuvant chemotherapy may indicate the favorable survival of patients with surgically-resected biliary tract cancers, specifically, in the tumoral PD-L1^(-) or tumor leptin^(-) subgroups and extrahepatic cholangiocarcinoma. PD-L1- or leptin-targeted therapy combined with conventional chemotherapy may benefit the tumoral PD-L1⁺ or leptin⁺ subgroups.

Immune checkpoints and their promising prospect in cholangiocarcinoma treatment in combination with other therapeutic approaches

Cholangiocarcinoma (CCA) is one of the malignant tumors that has shown rapid development in incidence and mortality in recent years. Like other types of cancer, patients with CCA experience alterations in the expression of immune checkpoints, indicating the importance of immune checkpoint inhibitors in treating CCA. The results of TCGA analysis in this study revealed a marginal difference in the expression of important immune checkpoints, Programmed cell death 1 (PD-1) and Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and their ligands in CCA samples compared to normal ones. This issue showed the importance of combination therapy in this cancer. This review considers CCA treatment and covers several therapeutic modalities or combined treatment strategies. We also cover the most recent developments in the field and outline the important areas of immune checkpoint molecules as prognostic variables and therapeutic targets in CCA.

[Research Advances of Immunotherapy of Exosome PD-L1 in Non-small Cell Lung Cancer]

Cancer immunotherapy is increasingly popular in the field of cancer treatment, and related research is emerging. For patients with non-small cell lung cancer (NSCLC), in recent years, immune checkpoint inhibitors (ICIs) represented by programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) immunosuppressants, have become one of the most promising treatments for malignant tumors. Immune checkpoint blockade therapy includes anti-cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) mAb, anti-PD-1 mAb and anti-PD-L1 mAb, with the best-known number of PD-L1 immunotherapy. At present, ICIs have achieved very good therapeutic results in clinical treatment, but with less effective efficiency, so we hope to obtain higher therapeutic efficiency. In recent years, exosomal PD-L1 has played an important role in the progress of immunotherapy for NSCLC. This paper reviews the effects of tumor exosomal PD-L1 protein on the tumor microenvironment, the effect prediction of immunotherapy, and as novel therapeutic strategies for immunotherapy in NSCLC.
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PD-1+ T-Cells Correlate with Nerve Fiber Density as a Prognostic Biomarker in Patients with Resected Perihilar Cholangiocarcinoma

Simple Summary

Recent studies have identified Nerve Fiber Density (NFD) as a prognostic biomarker for Cholangiocarcinoma (CCA). In the field of CCA treatment with checkpoint inhibitors (ICI) is increasing but not all patients respond. Good biomarkers to predict response to ICI are lacking. The present study investigates the immune cell composition and expression of checkpoint molecules in relation to NFD in perihilar cholangiocarcinoma (pCCA) patients. Our study identified NFD to correlate with PD-1+ T cells as a biomarker indicative for a good prognosis.

Abstract

Background and Aims: Perihilar cholangiocarcinoma (pCCA) is a hepatobiliary malignancy, with a dismal prognosis. Nerve fiber density (NFD)—a novel prognostic biomarker—describes the density of small nerve fibers without cancer invasion and is categorized into high numbers and low numbers of small nerve fibers (high vs low NFD). NFD is different than perineural invasion (PNI), defined as nerve fiber trunks invaded by cancer cells. Here, we aim to explore differences in immune cell populations and survival between high and low NFD patients. Approach and Results: We applied multiplex immunofluorescence (mIF) on 47 pCCA patients and investigated immune cell composition in the tumor microenvironment (TME) of high and low NFD. Group comparison and oncological outcome analysis was performed. CD8+PD-1 expression was higher in the high NFD than in the low NFD group (12.24 × 10⁻⁶ vs. 1.38 × 10⁻⁶ positive cells by overall cell count, p = 0.017). High CD8+PD-1 expression was further identified as an independent predictor of overall (OS; Hazard ratio (HR) = 0.41; p = 0.031) and recurrence-free survival (RFS; HR = 0.40; p = 0.039). Correspondingly, the median OS was 83 months (95% confidence interval (CI): 18–48) in patients with high CD8+PD-1+ expression compared to 19 months (95% CI: 5–93) in patients with low CD8+PD-1+ expression (p = 0.018 log rank). Furthermore, RFS was significantly lower in patients with low CD8+PD-1+ expression (14 months (95% CI: 6–22)) compared to patients with high CD8+PD-1+ expression (83 months (95% CI: 17–149), p = 0.018 log rank). Conclusions: PD-1+ T-cells correlate with high NFD as a prognostic biomarker and predict good survival; the biological pathway needs to be investigated.

Immune cell atlas of cholangiocarcinomas reveals distinct tumor microenvironments and associated prognoses

BACKGROUND

Immunotherapy has demonstrated a limited clinical efficacy in approximately 5% of cholangiocarcinoma. The main challenges for an effective immunotherapy response in cholangiocarcinoma arise from the tumor microenvironment, which is poorly understood.

METHODS

For a comprehensive analysis of the tumor microenvironment in cholangiocarcinoma, we performed multiplex immunohistochemistry with two 15-marker immune panels and Nanostring assays for a comprehensive analysis of 104 surgically resected cholangiocarcinomas including intrahepatic, hilar, and distal cholangiocarcinoma. We also validated some key findings with a batch integration analysis of published single cell RNA sequencing data.

RESULTS

This study found that natural killer cells occupy the largest immune cell compartment in cholangiocarcinoma. Granzyme-B+CD8+ effector T cells are significantly associated with better overall survival in both intrahepatic and distal cholangiocarcinoma. Above 85% of intrahepatic cholangiocarcinomas with higher density of PD-1-EOMES-CD8+ effector T cells are associated with long-term survival. However, only the density of PD-1-EOMES-CD8+ T cells in the tumor areas, but not in the peripheries of the tumors, is prognostic. In all three cholangiocarcinoma subtypes, T regulator cells are significantly associated with a poor prognosis; however, M1 and M2 tumor-associated macrophages or PD-L1+ tumor-associated macrophage demonstrate different prognostic values. Combining PD-L1+ M1 or M2, PD-L1- M1 or M2 tumor-associated macrophages, and T regulator cells to subgroup intrahepatic and distal cholangiocarcinoma, the prognosis is significantly better distinguished. Moreover, PD-L1- M2 tumor-associated macrophages is associated with a good prognosis in intrahepatic and distal cholangiocarcinoma, suggesting this subtype of M2 tumor-associated macrophages may be antitumoral. Interestingly, lower densities of various types of immunosuppressive cells are associated with decreased infiltration of effector T cells in distal and hilar cholangiocarcinoma, but not in intrahepatic cholangiocarcinoma. In intrahepatic cholangiocarcinoma, PD-L1+ tumor-associated macrophages exert their immunosuppressive function likely through promoting T cell exhaustion.

CONCLUSIONS

This study suggests that the densities of Granzyme-B+CD8+ effector T cells and non-exhausted PD-1-EOMES-CD8+ T cells and the PD-L1 status in the tumor-associated macrophages are prognostic makers in cholangiocarcinomas. The study also supports targeting PD-L1+ tumor-associated macrophages as the immunotherapy for cholangiocarcinoma.

Novel and emerging targets for cholangiocarcinoma progression: therapeutic implications

INTRODUCTION

Cholangiocarcinoma (CCA) is a heterogeneous group of aggressive biliary malignancies. While surgery and liver transplantation are the only potentially curative modalities for early-stage disease, limited options are available for most patients with incurable-stage disease. Survival outcomes remain dismal. Recent molecular profiling efforts have led to improved understanding of the genomic landscape of CCA and to the identification of subgroups with distinct diagnostic, prognostic, and therapeutic implications.

AREAS COVERED

: We provide an updated review and future perspectives on features of cholangiocarcinogenesis that can be translated into therapeutic biomarkers and targets. We highlight the critical studies that have established current systemic chemotherapy and targeted therapeutics, while elaborating on novel targeted and immunotherapeutic approaches in development. Relevant literature and clinical studies were identified by searching PubMed and www.ClinicalTrials.gov.

EXPERT OPINION

: While therapies targeting the various molecular subgroups of CCA are rapidly emerging and changing treatment paradigms, their success has been limited by the genetic heterogeneity of CCA and the plasticity of the targets. Novel strategies aiming to combine immunotherapy, chemotherapy, and molecularly-targeted therapeutics will be required to offer durable clinical benefit and maximize survival.

Application of Immune Checkpoint Inhibitors in the Treatment of Cholangiocarcinoma

Cholangiocarcinoma is a general term for intrahepatic and extrahepatic malignant tumors deriving in the biliary system. According to the location, it is divided into intrahepatic cholangiocarcinoma, hilar cholangiocarcinoma, and distal cholangiocarcinoma. Progressive cholangiocarcinoma yields poor outcomes with radiotherapy; therefore, there is an urgent need for new therapeutic breakthroughs. Immune checkpoint inhibitor (ICI) therapy brings the treatment for cancer into a new field, with the use of drugs targeting PD-1/PD-L1 and CTLA-4 considerably extending the survival of patients with melanoma, lung cancer, and other solid tumors. The FDA has approved the application of pembrolizumab for solid tumors with high microsatellite instability and defective mismatch repair, including cholangiocarcinoma. Moreover, the combination of ICIs with chemotherapy and radiation therapy showed good promise. The aim of the present study was to review the application of ICIs in the treatment of cholangiocarcinoma and to summarize the reported individualized immunotherapy-based protocols and ongoing clinical trials for clinical reference.

Lymphocyte-C-reactive protein ratio as a prognostic marker associated with the tumor immune microenvironment in intrahepatic cholangiocarcinoma

BACKGROUND

Changes in immune cell and inflammation-associated protein levels, either independently or in combination, are commonly used as prognostic factors for various cancers. The ratio of lymphocyte count to C-reactive protein concentration (lymphocyte-CRP ratio; LCR) is a recently identified prognostic marker for several cancers. Here, we examined the prognostic value of LCR and its relationship to various aspects of the tumor immune microenvironment in patients with intrahepatic cholangiocarcinoma (ICC).

METHODS

This was a single-center, retrospective study of patients who underwent surgical resection for ICC between 1998 and 2018. Patients were dichotomized into high- and low-LCR status groups, and the relationships between LCR status, prognosis, and other clinicopathological characteristics were analyzed. Tumor-infiltrating CD8+ and FOXP3s+ lymphocytes and tumor expression of CD34 and programmed death-ligand 1 were evaluated by immunohistochemical staining of resected tumors.

RESULTS

A total of 78 ICC patients were enrolled and assigned to the high (n = 44)- and low (n = 34)-LCR groups. Compared with the high-LCR group, patients in the low-LCR group had a significantly higher serum CA19-9 level (median 20.6 vs. 77.3 U/mL, P = 0.0017) and larger tumor size (median 3.5 vs. 5.5 cm, P = 0.0018). LCR correlated significantly with tumor microvessel density (r = 0.369, P = 0.0009) and CD8+ T lymphocyte infiltration (r = 0.377, P = 0.0007) but not with FOXP3+ T lymphocyte infiltration or tumor PD-L1 expression. Low-LCR status was significantly associated with worse overall survival by multivariate analysis (P = 0.0348).

CONCLUSIONS

Low-LCR status may reflect a poor anti-tumor immune response and predict worse outcomes in ICC patients.

Tumor necroptosis is correlated with a favorable immune cell signature and programmed death-ligand 1 expression in cholangiocarcinoma

Necroptosis, a regulated form of necrosis, has emerged as a novel therapeutic strategy that could enhance cancer immunotherapy. However, its role in tumorigenesis is still debated because recent studies have reported both anti- and pro-tumoral effects. Here, we aimed to systematically evaluate the associations between tumor necroptosis (mixed lineage kinase domain-like protein, MLKL; phosphorylated MLKL, pMLKL; and receptor-interacting protein kinase 1-receptor-interacting protein kinase 3, RIPK1-RIPK3 interaction) and tumor-infiltrating immune cells (CD8+ and FOXp3+ T cells and CD163+ M2 macrophages) and tumor PD-L1 by immunohistochemistry in 88 cholangiocarcinoma (CCA) patients who had undergone surgical resection. Their associations with clinicopathological characteristics, survival data, and prognosis were evaluated. MLKL was found to be an unfavorable prognostic factor (p-value = 0.023, HR = 2.070) and was inversely correlated with a clinically favorable immune cell signature (high CD8+/high FOXp3+/low CD163+). Both pMLKL and RIPK1-RIPK3 interaction were detected in CCA primary tissues. In contrast to MLKL, pMLKL status was significantly positively correlated with a favorable immune signature (high CD8+/high FOXp3+/low CD163+) and PD-L1 expression. Patients with high pMLKL-positive staining were significantly associated with an increased abundance of CD8+ T cell intratumoral infiltration (p-value = 0.006). Patients with high pMLKL and PD-L1 expressions had a longer overall survival (OS). The results from in vitro experiments showed that necroptosis activation in an RMCCA-1 human CCA cell line selectively promoted proinflammatory cytokine and chemokine expression. Jurkat T cells stimulated with necroptotic RMCCA-1-derived conditioned medium promoted PD-L1 expression in RMCCA-1. Our findings demonstrated the differential associations of necroptosis activation (pMLKL) and MLKL with a clinically favorable immune signature and survival rates and highlighted a novel therapeutic possibility for combining a necroptosis-based therapeutic approach with immune checkpoint inhibitors for more efficient treatment of CCA patients.

Prognostic Role of Immune Checkpoint Regulators in Cholangiocarcinoma: A Pilot Study

Cholangiocarcinoma (CCA) is a hepatobiliary malignancy associated with steadily increasing incidence and poor prognosis. Ongoing clinical trials are assessing the effectiveness and safety of a few immune checkpoint inhibitors (ICIs) in CCA patients. However, these ICI treatments as monotherapies may be effective for a proportion of patients with CCA. The prevalence and distribution of other immune checkpoints (ICs) in CCA remain unclear. In this pilot study, we screened databases of CCA patients for the expression of 19 ICs and assessed the prognostic significance of these ICs in CCA patients. Notably, expression of immune modulator IDO1 and PD-L1 were linked with poor overall survival, while FASLG and NT5E were related to both worse overall survival and progression-free survival. We also identified immune modulators IDO1, FASLG, CD80, HAVCR2, NT5E, CTLA-4, LGALS9, VTCN1 and TNFRSF14 that synergized with PD-L1 and correlated with worse patient outcomes. In vitro studies revealed that the expression of ICs was closely linked with aggressive CCA subpopulations, such as cancer stem cells and cells undergoing TGF-β and TNF-α-mediated epithelial-to-mesenchymal transition. These findings suggest that the aforementioned IC molecules may serve as potential prognostic biomarkers and drug targets in CCA patients, leading to lasting and durable treatment outcomes.

Prognostic impact of tumor microvessels in intrahepatic cholangiocarcinoma: association with tumor-infiltrating lymphocytes

Tumor microvessel density (MVD) is a prognostic factor for patients with intrahepatic cholangiocarcinoma (ICC). Tumor-infiltrating lymphocytes (TILs) are also key components of the tumor microenvironment that play important roles in ICC progression. This study aimed to clarify the relationships between the MVD and immune status and prognosis in patients with ICC. Immunohistochemical staining for cluster of differentiation 34 (CD34), cluster of differentiation 8 (CD8), forkhead box protein P3 (Foxp3), and programmed death-ligand 1 (PD-L1) was performed. The relationships between the MVD and clinicopathological characteristics and outcomes were analyzed. Additionally, the correlations between the MVD, CD8+ and Foxp3+ TIL counts, and PD-L1 expression were evaluated. One hundred ICC patients were classified into high (n = 50) and low (n = 50) MVD groups. The serum platelet and carbohydrate antigen 19-9 levels were higher in the low MVD group than in the high MVD group (P = 0.017 and P = 0.008, respectively). The low MVD group showed a significantly larger tumor size (P = 0.016), more frequent microvascular invasion (P = 0.001), and a higher rate of intrahepatic (P = 0.023) and lymph node (P < 0.001) metastasis than the high MVD group. Moreover, the MVD showed a high positive correlation with CD8+ TILs (r = 0.754, P < 0.001) and a negative correlation with Foxp3+ TILs (r = -0.302, P = 0.003). In contrast, no significant correlation was observed between the MVD and PD-L1 expression in cancer cells (P = 0.817). Patients with low MVDs had a significantly worse prognosis than those with high MVDs. Furthermore, multivariable analyses revealed that a low MVD influenced recurrence-free survival. A decreased intratumoral MVD might predict ICC patient outcomes. Tumor microvessels might be associated with ICC progression, possibly by altering TIL recruitment.

Programmed Death Ligand 1 Expression as a Prognostic Marker in Patients with Advanced Biliary Tract Cancer

BACKGROUND

Biliary tract cancer (BTC) is associated with poor prognosis because of its aggressive and heterogeneous nature. Programmed death ligand 1 (PD-L1) has been considered a novel biomarker for prognosis and response of immune checkpoint inhibitors in various tumors. However, there are limited data reporting on the role of PD-L1 in advanced BTC patients.

PATIENTS AND METHODS

We analyzed 186 patients with advanced BTC who received palliative gemcitabine and platinum between May 2010 and December 2019. All patients were evaluated for PD-L1 expression by combined positive score positivity.

RESULTS

Of the 186 patients, the primary tumor location was intrahepatic cholangiocarcinoma (IHCC) in 72 (38.7%), extrahepatic cholangiocarcinoma (EHCC) in 90 (48.4%), and gallbladder (GB) cancer in 24 (12.9%). Among all the patients, 53 (28.5%) had PD-L1 positivity. The median overall survival (OS) of patients with PD-L1 positivity or negativity was 12.1 and 15.4 months, respectively. The median progression-free survival (PFS) in patients with PD-L1 positivity or negativity was 5.7 and 7.1 months, respectively. OS and PFS were not statistically different between groups. In subgroup analysis, EHCC patients with PD-L1 negativity had more favorable OS (17.2 vs. 11.6 months, p = 0.002) and PFS (7.8 vs. 5.4 months, p = 0.005) than those who were PD-L1-positive. However, this finding was not reproduced in patients with IHCC or GB cancer.

CONCLUSION

This study demonstrated that PD-L1 expression might be a novel prognostic biomarker in patients with EHCC but not in patients with IHCC or GB cancer.

Obesity is a risk factor for intrahepatic cholangiocarcinoma progression associated with alterations of metabolic activity and immune status

Body mass index (BMI) is well known to be associated with poor prognosis in several cancers. The relationship between BMI and the long-term outcomes of patients with intrahepatic cholangiocarcinoma (ICC) is incompletely understood. This study investigated the relationships of BMI with clinicopathological characteristics and patient outcomes, focusing on metabolic activity and immune status. The relationship between BMI and the maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) was analyzed. In addition, immunohistochemistry was performed for programmed cell death-ligand 1 (PD-L1), cluster of differentiation 8 (CD8), and forkhead box protein P3 (Foxp3). Seventy-four patients with ICC were classified into normal weight (BMI < 25.0 kg/m², n = 48) and obesity groups (BMI ≥ 25.0 kg/m², n = 26), respectively. Serum carbohydrate antigen 19–9 levels were higher in the obesity group than in the normal weight group. Tumor size and the intrahepatic metastasis rate were significantly larger in the obesity group. Patients in the obesity group had significantly worse prognoses than those in the normal weight group. Moreover, BMI displayed a positive correlation with SUVmax on ¹⁸F-FDG PET/CT (n = 46, r = 0.5152). Patients with high ¹⁸F-FDG uptake had a significantly higher rate of PD-L1 expression, lower CD8 + tumor-infiltrating lymphocyte (TIL) counts, and higher Foxp3 + TIL counts. The elevated BMI might predict the outcomes of patients with ICC. Obesity might be associated with ICC progression, possibly through alterations in metabolic activity and the immune status.

Inhibition of T-cell-mediated immune response via the PD-1/ PD-L1 axis in cholangiocarcinoma cells

Cholangiocarcinoma (CCA) is a malignant biliary tract epithelium tumor. The programmed death-1 (PD-1)/programmed receptor-ligand 1 (PD-L1) signaling pathway has been implicated as an immune escape mechanism in several cancers. The present study aimed to assess the expression of PD-L1 on human CCA cell lines and its potential role in suppressing CD8⁺ T- cell function. A panel of intrahepatic CCA cell lines was evaluated for immune regulatory checkpoint ligands and inflammation markers. Effects of pro-inflammatory cytokine, interferon gamma (IFN-γ), on the expression of immune regulatory checkpoint ligands and inflammation markers were determined. The PD-L1 function was measured by co-culturing CCA cells with lymphocytes. Most of the selected Thai CCA cell lines, including HuCCA-1, RMCCA-1, KKU-100, and KKU-213, expressed higher PD-L1 than normal cholangiocyte MMNK-1 and ANK-1 cells. Both PD-L1 and cyclooxygenase-2 (COX-2) expressions were highest in HuCCA-1 cells. A 48 h treatment with IFN-γ increased the expression of PD-L1 and COX-2 in CCA cells. The expression of CTLA-4 ligands, including H7-1 and H7-2, did not change after IFN-γ treatment. Rofecoxib, a specific COX-2 inhibitor, mitigated IFN-γ-induced PD-L1 expression. After 48 h co-incubation, CD8⁺ T-cell apoptosis was increased as compared to the control group. Pretreatment of CCA cells with IFN-γ further increased CD8⁺ T-cell apoptosis. Pembrolizumab, an anti-PD-1 antibody, mitigated CCA cell escape phenomenon. The inhibition of T-cell-mediated immune response via the PD-L1/PD-1 axis are evidenced in intrahepatic CCA. Immunotherapy with checkpoint inhibitor offers a potentially therapeutic strategy for CCA patients; however, further in vivo and clinical studies are required.

Targeting the tumor microenvironment in cholangiocarcinoma: implications for therapy

Introduction: Cholangiocarcinoma (CCA) is a rare, deadly cancer that is characterized by an abundant desmoplastic stroma. Late diagnoses and limited available effective treatments are major problems with this malignancy. Targeting of the tumor microenvironment (TME) has emerged as a potential therapeutic strategy.Areas covered: In this review, we describe the role of the various compartments of the TME in CCA and focus on the preclinical rationale for the development of innovative therapies. Relevant literature was identified by a PubMed search covering the last decade (2010-2020).Expert opinion: Low efficacy of surgery and cytotoxic chemotherapy emphasizes the need for new therapeutic strategies and companion biomarkers. Single-cell RNA sequencing of the stroma is yielding a critical functional characterization of TME in CCA and is paving the way for immunotherapies and cancer-associated fibroblast and extracellular matrix-oriented treatments. We believe that the development of treatments targeting the components of the TME will produce the best results if in combination with cytotoxic chemotherapy. Biomarkers should be developed to define the patient population of interest for each combination strategy.

Clinicopathological and Prognostic Significance of Immunoscore and PD-L1 in Intrahepatic Cholangiocarcinoma

Background

An increasing amount of evidence reveals that immunosuppression is a major issue in cancer progression. The association of immunoscore (IS) and its impact on clinical outcome have been studied in many tumor types, but its significance in intrahepatic cholangiocarcinoma (ICC) is poorly known.

Methods

By immunohistochemistry, CD3 and CD8 expressions were assessed in tissue samples of 50 cases of postoperative ICC. The IS was determined by analyzing CD3+ and CD8+ expression data in different areas (intratumor and invasion margins). The relationship between IS and clinicopathological characteristics, including the overall survival (OS) and recurrence-free survival (RFS), was analyzed. In addition, PD-L1, a major regulator of immune escape, was also assessed in tumor cells by immunohistochemistry.

Results

IS was related to histological differentiation (P=0.026), the presence of lymphoid metastasis (P=0.034), and TNM clinical stages (P = 0.031) of ICC. High IS was significantly associated with better RFS (P=0.033) and OS (P=0.014). IS was an independent prognostic factor for better OS in multivariate analysis. PD-L1 expression was closely related to tumor vascular invasion (P=0.044). Although there was no association between PD-L1 expression and IS, high PD-L1 expression in tumor cells indicated poor RFS (P=0.017) and OS (P=0.004) in ICC.

Conclusion

The IS and PD-L1 may be used as a complement to the TNM system for predicting the prognosis of patients with ICC.

Intrahepatic cholangiocarcinoma: Morpho-molecular pathology, tumor reactive microenvironment, and malignant progression

Intrahepatic cholangiocarcinoma (iCCA) is a relatively rare, but highly lethal and biologically complex primary biliary epithelial cancer arising within liver. After hepatocellular carcinoma, iCCA is the second most common primary liver cancer, accounting for approximately 10-20% of all primary hepatic malignancies. Over the last 10-20 years, iCCA has become the focus of increasing concern largely due to its rising incidence and high mortality rates in various parts of the world, including the United States. The challenges posed by iCCA are daunting and despite recent progress in the standard of care and management options for iCCA, the prognosis for this cancer continues to be dismal. In an effort to provide a framework for advancing our understanding of iCCA malignant aggressiveness and therapy resistance, this review will highlight key etiological, biological, molecular, and microenvironmental factors hindering more effective management of this hepatobiliary cancer. Particular focus will be on critically reviewing the cell origins and morpho-molecular heterogeneity of iCCAs, providing mechanistic insights into high risk fibroinflammatory cholangiopathies associated with iCCA development, and notably discussing the deleterious role played by the tumor reactive desmoplastic stroma in regulating iCCA malignant progression, lymphangiogenesis, and tumor immunobiology.

Omics-Based Platforms: Current Status and Potential Use for Cholangiocarcinoma

Cholangiocarcinoma (CCA) has been identified as a highly malignant cancer that can be transformed from epithelial cells of the bile duct, including intrahepatic, perihilar and extrahepatic. High-resolution imaging tools (abdominal ultrasound, computed tomography and percutaneous transhepatic cholangial drainage) are recruited for diagnosis. However, the lack of early diagnostic biomarkers and treatment evaluation can lead to serious outcomes and poor prognosis (i.e., CA19-9, MUC5AC). In recent years, scientists have established a large number of omics profiles to reveal underlying mechanisms and networks (i.e., IL-6/STAT3, NOTCH). With these results, we achieved several genomic alteration events (i.e., TP53_mut, KRAS_mut) and epigenetic modifications (i.e., DNA methylation, histone modification) in CCA cells and clinical patients. Moreover, we reviewed candidate gene (such as NF-kB, YAP1) that drive gene transcription factors and canonical pathways through transcriptomics profiles (including microarrays and next-generation sequencing). In addition, the proteomics database also indicates which molecules and their directly binding status could trigger dysfunction signatures in tumorigenesis (carbohydrate antigen 19-9, mucins). Most importantly, we collected metabolomics datasets and pivotal metabolites. These results reflect the pharmacotherapeutic options and evaluate pharmacokinetic/pharmacodynamics in vitro and in vivo. We reversed the panels and selected many potentially small compounds from the connectivity map and L1000CDS² system. In this paper, we summarize the prognostic value of each candidate gene and correlate this information with clinical events in CCA. This review can serve as a reference for further research to clearly investigate the complex characteristics of CCA, which may lead to better prognosis, drug repurposing and treatment strategies.

News on immune checkpoint inhibitors as immunotherapy strategies in adult and pediatric solid tumors

Immune checkpoint inhibitors (ICIs) have shown unprecedented benefits in various adult cancers, and this success has prompted the exploration of ICI therapy even in childhood malignances. Although the use of ICIs as individual agents has achieved disappointing response rates, combinational therapies are likely to promise better results. However, only a subset of patients experienced prolonged clinical effects, thus suggesting the need to identify robust bio-markers that predict individual clinical response or resistance to ICI therapy as the main challenge. In this review, we focus on how the use of ICIs in adult cancers can be translated into pediatric malignances. We discuss the physiological mechanism of action of each IC, including PD-1, PD-L1 and CTLA-4 and the new emerging ones, LAG-3, TIM-3, TIGIT, B7-H3, BTLA and IDO-1, and evaluate their prognostic value in both adult and childhood tumors. Furthermore, we offer an overview of preclinical models and clinical trials currently under investigation to improve the effectiveness of cancer immunotherapies in these patients. Finally, we outline the main predictive factors that influence the efficacy of ICIs, in order to lay the basis for the development of a pan-cancer immunogenomic model, able to direct young patients towards more specific immunotherapy.

A pooled analysis of the prognostic value of PD-L1 in melanoma: evidence from 1062 patients

Background

Programmed death-ligand 1 (PD-L1) was the first identified ligand of programmed death-1 (PD-1). PD-1/PD-L1 interactions inhibit T cell-mediated immune responses, limit cytokine production, and promote tumor immune escape. Recently, many studies have investigated the prognostic value of PD-L1 expression in patients with melanoma. However, the results of these analyses remain a subject of debate. We have therefore carried out a meta-analysis to identify the prognostic role of PD-L1 in melanoma.

Methods

A thorough medical literature search was performed in the databases PubMed, Web of Science, and Embase until October 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated to evaluate the correlation between PD-L1 overexpression and prognosis. Publication bias was evaluated using Begg’s test and Egger’s test.

Results

Thirteen articles with 1062 enrolled patients were included in this meta-analysis. High PD-L1 expression did not correlate with overall survival (OS) (HR = 0.93, 95% CI 0.57–1.52, P = 0.781) or progression-free survival (PFS) (HR = 0.82, 95% CI 0.43–1.54, P = 0.535). However, PD-L1 overexpression correlated with the absence of lymph node (LN) metastasis (OR = 0.46, 95% CI 0.22–0.95, P = 0.036). Further, there was no significant relationship between PD-L1 expression and sex (OR = 1.29, 95% CI 0.90–1.84, P = 0.159), age (OR = 0.90, 95% CI 0.51–1.57, P = 0.708), or Eastern Cooperative Oncology Group Performance Status (OR = 0.55, 95% CI 0.06–4.83, P = 0.592).

Conclusions

This meta-analysis suggested that PD-L1 expression did not predict an inferior prognosis in patients with melanoma. However, high PD-L1 expression was associated with absence of LN metastasis in such patients.

Prognostic impact of CD8+ T cell distribution and its association with the HLA class I expression in intrahepatic cholangiocarcinoma

PURPOSE

A lack of effective systemic therapy is one reason for the poor prognosis of intrahepatic cholangiocarcinoma. Newly developed immune checkpoint inhibitors function by minimizing CD8+ T cell suppression to improve tumor-specific responses. This study aimed to examine the characteristics of CD8+ T cells in intrahepatic cholangiocarcinoma.

METHODS

Clinicopathological data, including the overall survival, of 69 cases of postoperative intrahepatic cholangiocarcinoma were prospectively investigated. We then immunohistochemically stained for CD8, Foxp3, CD163, PD-L1, and human leukocyte antigen (HLA) class I and counted the number of CD8+ T cells, Foxp3+ T cells, and CD163+ macrophages in different areas (outer border, interborder, and intratumor).

RESULTS

A significant difference was found in the 5-year overall survival between the CD8+ T cell high group (45.5%) and low group (24.7%) in the outer border area (p = 0.0103). Furthermore, the number of CD8+ T cells and the high expression of HLA class I were positively correlated (p = 0.0341).

CONCLUSION

The number of CD8+ T cells in the outer border area of the tumor correlated with the HLA class I expression of intrahepatic cholangiocarcinoma and may therefore be a prognostic factor for patients with postoperative intrahepatic cholangiocarcinoma.

Exosomal PD-L1: New Insights Into Tumor Immune Escape Mechanisms and Therapeutic Strategies

As a classical immune checkpoint molecule, PD-L1 on the surface of tumor cells plays a pivotal role in tumor immunosuppression, primarily by inhibiting the antitumor activities of T cells by binding to its receptor PD-1. PD-1/PD-L1 inhibitors have demonstrated unprecedented promise in treating various human cancers with impressive efficacy. However, a significant portion of cancer patients remains less responsive. Therefore, a better understanding of PD-L1-mediated immune escape is imperative. PD-L1 can be expressed on the surface of tumor cells, but it is also found to exist in extracellular forms, such as on exosomes. Recent studies have revealed the importance of exosomal PD-L1 (ExoPD-L1). As an alternative to membrane-bound PD-L1, ExoPD-L1 produced by tumor cells also plays an important regulatory role in the antitumor immune response. We review the recent remarkable findings on the biological functions of ExoPD-L1, including the inhibition of lymphocyte activities, migration to PD-L1-negative tumor cells and immune cells, induction of both local and systemic immunosuppression, and promotion of tumor growth. We also discuss the potential implications of ExoPD-L1 as a predictor for disease progression and treatment response, sensitive methods for detection of circulating ExoPD-L1, and the novel therapeutic strategies combining the inhibition of exosome biogenesis with PD-L1 blockade in the clinic.