Expression of Programmed Death Ligand 1 Is Associated with the Prognosis of Intrahepatic Cholangiocarcinoma

PD-L1 Expression in Biliary Tract Cancer: Comparison Across Antibody Clones and Role as a Predictor of Response to Chemoimmunotherapy: A Meta-Analysis

PURPOSE

PD-L1 positivity in biliary tract cancers (BTCs) is reported from 4% to 76%. BTC clinical trials have not demonstrated PD-L1 expression as a predictor of response to chemotherapy combined with immune checkpoint inhibitor (chemo-ICI). This meta-analysis examines PD-L1 positivity rates in BTC and association between PD-L1 expression and outcomes in patients treated with chemo-ICI.

MATERIALS AND METHODS

Observational studies or clinical trials reporting tissue-based PD-L1 expression by Tumor Proportional Score/Combined Positive Score using immunohistochemistry were included. Clinical trials of BTC treated with chemo-ICI were included to assess PD-L1 expression on treatment response. PubMed, Embase, Web of Science, and Cochrane Library were searched for relevant studies before November 15, 2023. Methods of PD-L1 assessment, including antibody clone, cutoff for PD-L1 positivity, and anatomical subtype, were analyzed. Overall survival (OS) and objective response rates (ORRs) were the main outcomes. The generic inverse variance method and random-effect model were used to assess pooled effect sizes.

RESULTS

Fifty-six studies met eligibility criteria. Among 7,768 patients, pooled PD-L1 positivity was 30%. Positivity rates varied significantly by antibody clone (5H1, 58% v SP142, 17%; P = .02). Clinical trials reported a higher positivity rate compared with observational studies (48% v 26%; P < .01). Across five phase I/II clinical trials (194 patients), PD-L1 ≥1% patients tended to have a better ORR than PD-L1 <1% patients (64% v 46%; P = .08). In two randomized controlled trials (874 patients), PD-L1 ≥1% had a statistically significant improvement in OS (hazard ratio [HR], 0.83; P < .01), while PD-L1 <1% did not (HR, 0.85; P = .2).

CONCLUSION

Given the high PD-L1 positivity rate seen in this study, as well as a possible signal of predictive response for chemo-ICI treatment, PD-L1 expression should be further explored as a predictive biomarker.

Conversion treatment for advanced intrahepatic cholangiocarcinoma: Opportunities and challenges

The prevalence of intrahepatic cholangiocarcinoma (ICC) is increasing globally. Despite advancements in comprehending this intricate malignancy and formulating novel therapeutic approaches over the past few decades, the prognosis for ICC remains poor. Owing to the high degree of malignancy and insidious onset of ICC, numerous cases are detected at intermediate or advanced stages of the disease, hence eliminating the chance for surgical intervention. Moreover, because of the highly invasive characteristics of ICC, recurrence and metastasis postresection are prevalent, leading to a 5-year survival rate of only 20%-35% following surgery. In the past decade, different methods of treatment have been investigated, including transarterial chemoembolization, transarterial radioembolization, radiotherapy, systemic therapy, and combination therapies. For certain patients with advanced ICC, conversion treatment may be utilized to facilitate surgical resection and manage disease progression. This review summarizes the definition of downstaging conversion treatment and presents the clinical experience and evidence concerning conversion treatment for advanced ICC.

The Immune Landscape and Its Potential for Immunotherapy in Advanced Biliary Tract Cancer

Biliary tract cancers (BTC) are a highly heterogeneous group of cancers at the genomic, epigenetic and molecular levels. The vast majority of patients initially present at an advanced (unresectable) disease stage due to a lack of symptoms and an aggressive tumour biology. Chemotherapy has been the mainstay of treatment in patients with advanced BTC but the survival outcomes and prognosis remain poor. The addition of immune checkpoint inhibitors (ICI) to chemotherapy have shown only a marginal benefit over chemotherapy alone due to the complex tumour immune microenvironment of these cancers. This review appraises our current understanding of the immune landscape of advanced BTC, including emerging transcriptome-based classifications, highlighting the mechanisms of immune evasion and resistance to ICI and their therapeutic implications. It describes the shifting treatment paradigm from traditional chemotherapy to immunotherapy combinations as well as the potential biomarkers for predicting response to ICI.

Factors associated with prognosis and staging of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a relatively rare but aggressive primary liver cancer with a poor prognosis. A number of established clinical and pathologic factors correlate with prognosis, and this is reflected in the American Joint Committee on Cancer (AJCC) 8th Edition staging manual. Researchers have identified areas for improvement in staging and prognostication of ICC using more nuanced tools, including serum biomarkers, molecular profiling, immunophenotyping, and multimodal prognostic scoring systems. These data have led to proposals of novel staging systems that attempt to improve the correlation between stage and prognosis. More accurate staging tools may aid in treatment decisions that are tailored to each individual patient, to maximize therapy for individuals most likely to benefit and to avoid unnecessary toxicity and decision regret in those for whom aggressive treatment is unlikely to alter outcomes. Artificial intelligence and machine learning may help researchers develop new models that predict outcomes with more accuracy and precision.

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.

Interleukin-6 and Lymphocyte-to-Monocyte Ratio Indices Identify Patients with Intrahepatic Cholangiocarcinoma

BACKGROUND AND AIMS

Intrahepatic cholangiocarcinoma (iCCA) is a fatal biliary tract cancer with a dismal prognosis due to ineffective diagnostic tools with limited clinical utility. This study investigated peripheral blood indices and cytokine levels to diagnose iCCA.

METHODS

Blood samples were collected from healthy subjects (n = 48) and patients with advanced-stage iCCA (n = 47) during a phase I and then phase II trial, respectively. Serum cytokines were measured using a flow cytometer. The peripheral blood indices were estimated based on laboratory data. Multi-linear regression analysis was applied, followed by a probability transformation. The cut-off value and model accuracy were determined using the receiver operating curve (ROC) and the area under the curve (AUC).

RESULTS

The interleukin-6 (IL6) and lymphocyte-to-monocyte ratio (LMR) were potential predictors of iCCA [AUC = 0.91 (0.85-0.97) and 0.81 (0.68-0.93); sensitivity = 0.70 and 0.91; specificity = 0.91 and 0.85, respectively]. Patients with IL6 concentrations higher than 11.635 pg/mL (OR = 23.33, p < 0.001) or LMR lower than 7.2 (OR = 58.08, p < 0.001) are at risk of iCCA development. Patients with IL6 levels higher than 21.83 pg/mL, between 15.95 and 21.83 pg/mL, between 8.8 and 15.94 pg/mL, and lower than 8.8 pg/mL were classified as very high-, high-, intermediate-, and low-risk, respectively. Patients with an LMR between 1 and 3.37, 3.38 and 5.76, 5.77 and 7.18, and higher than 7.18 were classified as very high-, high-, intermediate-, and low-risk, respectively.

CONCLUSIONS

LMR is recommended for iCCA screening since the estimation is based on a routine laboratory test, which is available in most hospitals.

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.

The present roles and future perspectives of Interleukin-6 in biliary tract cancer

Biliary tract cancer (BTC) is a highly malignant tumor that originates from bile duct epithelium and is categorized into intrahepatic cholangiocarcinoma (iCCA), perihilar cholangiocarcinoma (pCCA), distal cholangiocarcinoma (dCCA) and gallbladder cancer (GBC) according to the anatomic location. Inflammatory cytokines generated by chronic infection led to an inflammatory microenvironment which influences the carcinogenesis of BTC. Interleukin-6 (IL-6), a multifunctional cytokine secreted by kupffer cells, tumor-associated macrophages, cancer-associated fibroblasts (CAFs) and cancer cells, plays a central role in tumorigenesis, angiogenesis, proliferation, and metastasis in BTC. Besides, IL-6 serves as a clinical biomarker for diagnosis, prognosis, and monitoring for BTC. Moreover, preclinical evidence indicates that IL-6 antibodies could sensitize tumor immune checkpoint inhibitors (ICIs) by altering the number of infiltrating immune cells and regulating the expression of immune checkpoints in the tumor microenvironment (TME). Recently, IL-6 has been shown to induce programmed death ligand 1 (PD-L1) expression through the mTOR pathway in iCCA. However, the evidence is insufficient to conclude that IL-6 antibodies could boost the immune responses and potentially overcome the resistance to ICIs for BTC. Here, we systematically review the central role of IL-6 in BTC and summarize the potential mechanisms underlying the improved efficacy of treatments combining IL-6 antibodies with ICIs in tumors. Given this, a future direction is proposed for BTC to increase ICIs sensitivity by blocking IL-6 pathways.

Lacking Immunotherapy Biomarkers for Biliary Tract Cancer: A Comprehensive Systematic Literature Review and Meta-Analysis

BACKGROUND

Immunotherapy has recently been incorporated into the spectrum of biliary tract cancer (BTC) treatment. The identification of predictive response biomarkers is essential in order to identify those patients who may benefit most from this novel treatment option. Here, we propose a systematic literature review and a meta-analysis of PD-1, PD-L1, and other immune-related biomarker expression levels in patients with BTC.

METHODS

Prisma guidelines were followed for this systematic review and meta-analysis. Eligible studies were searched on PubMed. Studies published between 2017 and 2022, reporting data on PD-1/PD-L1 expression and other immune-related biomarkers in patients with BTC, were considered eligible.

RESULTS

A total of 61 eligible studies were identified. Despite the great heterogeneity between 39 studies reporting data on PD-L1 expression, we found a mean PD-L1 expression percentage (by choosing the lowest cut-off per study) of 25.6% (95% CI 21.0 to 30.3) in BTCs. The mean expression percentages of PD-L1 were 27.3%, 21.3%, and 27.4% in intrahepatic cholangiocarcinomas (iCCAs-15 studies), perihilar-distal CCAs (p/dCCAs-7 studies), and gallbladder cancer (GBC-5 studies), respectively. Furthermore, 4.6% (95% CI 2.38 to 6.97) and 2.5% (95% CI 1.75 to 3.34) of BTCs could be classified as TMB-H and MSI/MMRd tumors, respectively.

CONCLUSION

From our analysis, PD-L1 expression was found to occur approximately in 26% of BTC patients, with minimal differences based on anatomical location. TMB-H and MSI molecular phenotypes occurred less frequently. We still lack a reliable biomarker, especially in patients with mismatch-proficient tumors, and we must need to make an effort to conceive new prospective biomarker discovery studies.

New Era of Immune-Based Therapy in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (CC) accounts for approximately 20% of all biliary tract cancer (BTC) cases and 10-15% of all primary liver cancer cases. Many patients are diagnosed with unresectable BTC, and, even among patients with resectable BTC, the 5-year survival rate is approximately 20%. The BTC incidence rate is high in Southeast and East Asia and has increased worldwide in recent years. Since 2010, cytotoxic chemotherapy, particularly combination gemcitabine + cisplatin (ABC-02 trial), has been the first-line therapy for patients with BTC. In 2022, a multicenter, double-blind, randomized phase 3 trial (TOPAZ-1 trial) examined the addition of programmed death-ligand 1 immunotherapy (durvalumab) to combination gemcitabine + cisplatin for BTC treatment, resulting in significantly improved survival without notable additional toxicity. As a result of this trial, this three-drug combination has become the new standard first-line therapy, leading to notable advances in BTC management for the first time since 2010. The molecular profiling of BTC has continued to drive the development of new targeted therapies for use when first-line therapies fail. Typically, second-line therapy decisions are based on identified genomic alterations in tumor tissue. Mutations in fibroblast growth factor receptor 1/2/3, isocitrate dehydrogenase 1/2, and neurotrophic tyrosine receptor kinase A/B/C are relatively frequent in intrahepatic CC, and precision medicines are available that can target associated pathways. In this review, we suggest strategies for systemic pharmacotherapy with a focus on intrahepatic CC, in addition to presenting the results and safety outcomes of clinical trials evaluating immune checkpoint inhibitor therapies in BTC.

Immune microenvironment of cholangiocarcinoma: Biological concepts and treatment strategies

Cholangiocarcinoma is characterized by a poor prognosis with limited treatment and management options. Chemotherapy using gemcitabine with cisplatin is the only available first-line therapy for patients with advanced cholangiocarcinoma, although it offers only palliation and yields a median survival of < 1 year. Recently there has been a resurgence of immunotherapy studies focusing on the ability of immunotherapy to inhibit cancer growth by impacting the tumor microenvironment. Based on the TOPAZ-1 trial, the US Food and Drug Administration has approved the combination of durvalumab and gemcitabine with cisplatin as the first-line treatment of cholangiocarcinoma. However, immunotherapy, like immune checkpoint blockade, is less effective in cholangiocarcinoma than in other types of cancer. Although several factors such as the exuberant desmoplastic reaction are responsible for cholangiocarcinoma treatment resistance, existing literature on cholangiocarcinoma cites the inflammatory and immunosuppressive environment as the most common factor. However, mechanisms activating the immunosuppressive tumor microenvironment contributing to cholangiocarcinoma drug resistance are complicated. Therefore, gaining insight into the interplay between immune cells and cholangiocarcinoma cells, as well as the natural development and evolution of the immune tumor microenvironment, would provide targets for therapeutic intervention and improve therapeutic efficacy by developing multimodal and multiagent immunotherapeutic approaches of cholangiocarcinoma to overcome the immunosuppressive tumor microenvironment. In this review, we discuss the role of the inflammatory microenvironment-cholangiocarcinoma crosstalk and reinforce the importance of inflammatory cells in the tumor microenvironment, thereby highlighting the explanatory and therapeutic shortcomings of immunotherapy monotherapy and proposing potentially promising combinational immunotherapeutic strategies.

Prognostic role of PD-L1 expression in patients with salivary gland carcinoma: A systematic review and meta-analysis

Background

Although programmed cell death-ligand 1 (PD-L1) has been recognized as a potential marker in several cancers, the relationship between PD-L1 expression and survival in patients with salivary gland carcinoma (SGC) has remained unclear. We aimed to evaluate the association of PD-L1 expression with clinicopathological features and prognosis in SGC patients.

Methods

The databases Ovid Medline, PubMed, Scopus, and EMBASE were searched for relevant studies that detected PD-L1 expression in SGC. The meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), and the reporting recommendations for tumor marker prognostic studies (REMARK) was used to assess the quality of research eligible for this meta-analysis. Included studies were assessed using the Quality in Prognosis Studies (QUIPS) tool. Odds ratios (ORs) with 95% confidence interval (CI) were calculated to estimate the correlation between PD-L1 expression and clinicopathological features. Hazard ratios (HRs) with 95% CI were applied to assess the association between PD-L1 expression and survival outcomes of patients.

Results

A total of ten studies (including 952 patients with SGC) were evaluated. The meta-analysis showed that positive PD-L1 expression in SGC was significantly associated with male patients, older age, Tumor stage, lymph node metastasis, high pathological grade, and non-adenoid cystic carcinoma subtype. The pooled data demonstrated that high PD-L1 expression was associated with poor overall survival and disease-free survival. There was no significant correlation between PD-L1 expression and progression-free survival or disease-specific survival of SGC patients.

Conclusion

According to the meta-analysis, positive PD-L1 expression may play an important role as an effective marker of poor prognosis in patients with SGC. However, large-scale, prospective investigations are still needed to confirm the findings. The assessment of PD-L1 expression may aid in the personalized management of SGC.

Immune Checkpoint Inhibitors: The Emerging Cornerstone in Cholangiocarcinoma Therapy?

BACKGROUND

Cholangiocarcinoma (CCA) encompasses a heterogeneous group of malignant tumors with dismal prognosis and increasing incidence worldwide. Both late diagnosis due to the lack of early symptoms and the refractory nature of these tumors seriously compromise patients' welfare and outcomes.

SUMMARY

During the last decade, immunotherapy and, more specifically, modulation of immune checkpoints-mediated signaling pathways have been under the spotlight in the field of oncology, emerging as a potential therapeutic approach for the treatment of several cancers, including CCA. Generally, high expression levels of immune checkpoints in patients with CCA have been associated with worse clinical outcomes, particularly with shorter overall survival and relapse-free survival. Thus, immune checkpoint inhibitors (ICIs), which mainly constitute different monoclonal antibodies, have been developed in order to hamper the immune checkpoint-mediated pathways. Interestingly, chemotherapy may increase the expression of immune checkpoints, while other therapeutic approaches such as ablative and targeted therapies may enhance their antitumor activity. In this sense, several clinical trials evaluated the safety and efficacy of ICIs for CCA, both as a monotherapy and in combination with other ICIs or loco-regional and systemic therapies. Additionally, many other clinical trials are currently ongoing and results are eagerly awaited. Here, we summarize the key aspects of immune checkpoint molecules as prognostic factors and therapeutic targets in CCA, highlighting the most recent advances in the field and future research directions.

KEY MESSAGES

(1) Effective therapeutic approaches for CCA are urgently needed. (2) Expression levels of immune checkpoints in patients with CCA have been proposed to be related with clinical outcomes. (3) Combination of different ICIs may outperform the efficacy of ICI monotherapy for CCA treatment. (4) Recent studies point toward the combination of ICIs and other common therapies, especially chemotherapy, as a promising strategy for treatment of CCA patients.

High TIL, HLA, and Immune Checkpoint Expression in Conventional High-Grade and Dedifferentiated Chondrosarcoma and Poor Clinical Course of the Disease

Purpose

The aim of this study was to characterize chondrosarcoma tumor infiltration by immune cells and the expression of immunologically relevant molecules. This information may contribute to our understanding of the role of immunological events in the pathogenesis of chondrosarcoma and to the rational design of immunotherapeutic strategies.

Patients and Methods

A tissue microarray (TMA) containing 52 conventional and 24 dedifferentiated chondrosarcoma specimens was analyzed by immunohistochemical staining for the expression of parameters associated with tumor antigen-specific immune responses, namely, CD4⁺ and CD8⁺ tumor infiltrating lymphocytes (TILs) and the expression of HLA class I heavy chain, beta-2 microglobulin (β2m), HLA class II and immune checkpoint molecules, B7-H3 and PD-1/PD-L1. The results were correlated with histopathological characteristics and the clinical course of the disease.

Results

CD8⁺ TILs were present in 21% of the conventional and 90% of the dedifferentiated chondrosarcoma tumors tested. B7-H3 was expressed in 69% of the conventional and 96% of the dedifferentiated chondrosarcoma tumors tested. PD-1 and PD-L1 were expressed 53% and 33% respectively of the dedifferentiated tumors tested. PD-L1 expression was associated with shorter time to metastasis.

Conclusion

The tumor infiltration by lymphocytes suggests that chondrosarcoma is immunogenic. Defects in HLA class I antigen and expression of the checkpoint molecules B7-H3 and PD-1/PD-L1 suggest that tumor cells utilize escape mechanisms to avoid immune recognition and destruction. This data implies that chondrosarcoma will benefit from strategies that enhance the immunogenicity of tumor antigens and/or counteract the escape mechanisms.

Implication of CD69+ CD103+ tissue-resident-like CD8+ T cells as a potential immunotherapeutic target for cholangiocarcinoma

BACKGROUND

The heterogeneous immune landscapes of intrahepatic cholangiocarcinoma (ICC) remain largely unknown. Here we aimed to investigate the implications of tissue-resident memory (TRM)-related features of tumour-infiltrating CD8⁺ T cells (CD8⁺ TILs) from ICC patients.

METHODS

From ICC patients, we obtained blood samples and ICC surgical specimens (n = 33). We performed multicolour flow cytometry, multiplexed immunohistochemistry and RNA sequencing.

RESULTS

When compared to peripheral CD8⁺ T cells, the CD8⁺ TILs included significantly higher proportions of the CD69⁺ CD103^- and CD69⁺ CD103⁺ TRM-like subsets (P < .001 for both). Relative to CD69^- and CD69⁺ CD103^- cells, the CD69⁺ CD103⁺ CD8⁺ TILs harboured higher levels of T-cell markers representing tumour specificity (ie CD39), proliferation (ie Ki-67) and T-cell activation (ie HLA-DR and CD38) (all P < .001). Moreover, compared to the stroma, the tumour margin and core density each had a significantly higher density of CD103⁺ CD8⁺ TILs (P < .001 for both). ICCs with high proportions of CD69⁺ CD103⁺ cells displayed higher levels of parameters associated with response to immune checkpoint inhibitors (ICIs)-including number of CD8⁺ TIL infiltrates (P = .019), PD-L1 expression in the tumour (P = .046) and expression of the T cell-inflamed gene signature (P < .001). ICCs with lower proportions of CD69⁺ CD103⁺ CD8⁺ TILs exhibited significant enrichment of genes related to the Wnt/β-catenin (P < .001) and TGF-β pathways (P = .002).

CONCLUSION

CD69⁺ CD103⁺ TRM-like CD8⁺ TILs represent prominent tumour-specific immune responses and hold promise as a potential therapeutic target in ICC patients. Differential TRM-related features of ICCs may help develop future immunotherapeutic strategies such as maximizing TRM responses or inhibiting pathways contributing to immune evasion.

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.

Prognostic and Clinicopathological Significance of PD-L1 in Patients with Cholangiocarcinoma: A Meta-Analysis

Background

In recent years, there is growing literature on the prognostic significance of programmed death-ligand 1 (PD-L1) in cholangiocarcinoma (CCA); however, data have been conflicting. Therefore, the objective of this study was to assess the correlation between PD-L1 and prognosis in CCA through meta-analysis.

Methods

Published studies were retrieved from the Web of Science, PubMed, Embase, and Cochrane Library up to April 17, 2020. The relationships between PD-L1 expression and survival outcomes were assessed using hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Eighteen studies consisting of 2012 patients were included. Overexpression of PD-L1 was significantly associated with worse overall survival (OS) (HR = 1.58, 95%CI = 1.30 - 1.92, p < 0.001) but not with poor disease-free survival (DFS) (HR = 1.03, 95%CI = 0.68 - 1.55, p = 0.895) in CCA. Moreover, PD-L1 was associated with low differentiation (OR = 1.43, 95%CI = 1.09 - 1.87, p = 0.010) and higher pN stage (OR = 1.45, 95%CI = 1.10 - 1.92, p = 0.009) but not with sex, TNM stage, vascular invasion, perineural invasion, age, or tumor size.

Conclusion

High PD-L1 expression was associated with worse OS, poor differentiation, and higher pN stage in patients with CCA. PD-L1 could be a potential prognostic marker in CCA.

Prognostic role of programmed death-ligand 1 expression in patients with biliary tract cancer: a meta-analysis

Previous studies investigated the prognostic role of programmed death-ligand 1 (PD-L1) expression in patients with biliary tract cancer (BTC); however, the results remained controversial. Therefore, we conducted the current meta-analysis with the aim of clarifying the association between PD-L1 expression and prognosis as well as with several important clinicopathological features of BTC. We searched PubMed, Embase, and Web of Science for relevant studies. Studies that detected PD-L1 expression in tumor cells by using immunohistochemistry (IHC) were selected. Pooled hazard ratios (HRs) and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the correlations. In total, 15 independent studies with 1,776 patients were included in this meta-analysis. The pooled data demonstrated that high PD-L1 expression was associated with poor overall survival (n=15, HR=1.79, 95% CI=1.55-2.07, p<0.001). The correlation between PD-L1 expression and disease-free survival was not significant (n=6, HR=1.38, 95% CI=1.00-1.91, p=0.051). In addition, no significant correlation was observed between PD-L1 expression and clinical features in patients with BTC. Our study results showed that PD-L1 expression could play a pivotal role as an effective factor of poor prognosis in patients with BTC.