Identification of Four Immune Subtypes Characterized by Distinct Composition and Functions of Tumor Microenvironment in Intrahepatic Cholangiocarcinoma

Whole-Genome DNA Methylation Profiling of Intrahepatic Cholangiocarcinoma Reveals Prognostic Subtypes with Distinct Biological Drivers

Intrahepatic cholangiocarcinoma (iCCA) is the second most prevalent primary liver cancer. Although the genetic characterization of iCCA has led to targeted therapies for treating tumors with FGFR2 alterations and IDH1/2 mutations, only a limited number of patients can benefit from these strategies. Epigenomic profiles have emerged as potential diagnostic and prognostic biomarkers for improving the treatment of cancers. In this study, we conducted whole-genome bisulfite sequencing on 331 iCCAs integrated with genetic, transcriptomic, and proteomic analyses, demonstrating the existence of four DNA methylation subtypes of iCCAs (S1-S4) that exhibited unique postoperative clinical outcomes. The S1 group was an IDH1/2 mutation-specific subtype with moderate survival. The S2 subtype was characterized by the lowest methylation level and the highest mutational burden among the four subtypes and displayed upregulation of a gene-expression pattern associated with cell cycle/DNA replication. The S3 group was distinguished by high interpatient heterogeneity of tumor immunity, a gene-expression pattern associated with carbohydrate metabolism, and an enrichment of KRAS alterations. Patients with the S2 and S3 subtypes had the shortest survival among the four subtypes. Tumors in the S4 subtype, which had the best prognosis, showed global methylation levels comparable to normal controls, increased FGFR2 fusions/BAP1 mutations, and the highest copy-number variant burdens. Further integrative and functional analyses identified GBP4 demethylation, which is highly prevalent in the S2 and S3 groups, as an epigenetic oncogenic factor that regulates iCCA proliferation, migration, and invasion. Together, this study identifies prognostic methylome alterations and epigenetic drivers in iCCA.

SIGNIFICANCE

Characterization of the DNA methylome of intrahepatic cholangiocarcinoma integrated with genomic, transcriptomic, and proteomic analyses uncovers molecular mechanisms affected by genome-wide DNA methylation alterations, providing a resource for identifying potential therapeutic targets.

Identification of clinically relevant subsets CD39+PD-1+CD8+ T cells and CD39+ regulatory T cells in intrahepatic cholangiocarcinoma using single-cell CyTOF

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive liver malignancy with limited treatment options and a dismal prognosis. The tumor immune microenvironment (TIME) is crucial for iCCA progression, yet its comprehensive characterization remains incomplete. This study utilized mass cytometry by time of flight (CyTOF) to comprehensively analyze immune cell populations in fresh iCCA tumor samples and adjacent peritumor liver tissues. Notably, NK cell percentages significantly decreased in iCCA lesions compared to peritumor liver tissues. Conversely, an enrichment of immunosuppressive CD39+Foxp3+CD4+ regulatory T cells (CD39+T-regs) and exhausted-like CD8+T cells (with pronounced CD39 and PD-1 expression) within TIME was identified and confirmed by multiplex immunofluorescence staining in an independent patient cohort (n = 140). Crucially, tumor-infiltrating CD39+T-regs and CD39+PD-1+CD8+T cells emerged as independent prognostic indicators associated with an unfavorable prognosis in iCCA. These findings unveil the intricate immune landscape within iCCA, offering valuable insights for disease management and novel cancer immunotherapies.

Radiomics of Intrahepatic Cholangiocarcinoma and Peritumoral Tissue Predicts Postoperative Survival: Development of a CT-Based Clinical-Radiomic Model

BACKGROUND

For many tumors, radiomics provided a relevant prognostic contribution. This study tested whether the computed tomography (CT)-based textural features of intrahepatic cholangiocarcinoma (ICC) and peritumoral tissue improve the prediction of survival after resection compared with the standard clinical indices.

METHODS

All consecutive patients affected by ICC who underwent hepatectomy at six high-volume centers (2009-2019) were considered for the study. The arterial and portal phases of CT performed fewer than 60 days before surgery were analyzed. A manual segmentation of the tumor was performed (Tumor-VOI). A 5-mm volume expansion then was applied to identify the peritumoral tissue (Margin-VOI).

RESULTS

The study enrolled 215 patients. After a median follow-up period of 28 months, the overall survival (OS) rate was 57.0%, and the progression-free survival (PFS) rate was 34.9% at 3 years. The clinical predictive model of OS had a C-index of 0.681. The addition of radiomic features led to a progressive improvement of performances (C-index of 0.71, including the portal Tumor-VOI, C-index of 0.752 including the portal Tumor- and Margin-VOI, C-index of 0.764, including all VOIs of the portal and arterial phases). The latter model combined clinical variables (CA19-9 and tumor pattern), tumor indices (density, homogeneity), margin data (kurtosis, compacity, shape), and GLRLM indices. The model had performance equivalent to that of the postoperative clinical model including the pathology data (C-index of 0.765). The same results were observed for PFS.

CONCLUSIONS

The radiomics of ICC and peritumoral tissue extracted from preoperative CT improves the prediction of survival. Both the portal and arterial phases should be considered. Radiomic and clinical data are complementary and achieve a preoperative estimation of prognosis equivalent to that achieved in the postoperative setting.

Heterogeneity in Liver Cancer Immune Microenvironment: Emerging Single-Cell and Spatial Perspectives

Primary liver cancer is a solid malignancy with a high mortality rate. The success of immunotherapy has shown great promise in improving patient care and highlights a crucial need to understand the complexity of the liver tumor immune microenvironment (TIME). Recent advances in single-cell and spatial omics technologies, coupled with the development of systems biology approaches, are rapidly transforming the landscape of tumor immunology. Here we review the cellular landscape of liver TIME from single-cell and spatial perspectives. We also discuss the cellular interaction networks within the tumor cell community in regulating immune responses. We further highlight the challenges and opportunities with implications for biomarker discovery, patient stratification, and combination immunotherapies.

Clinical outcomes of immune checkpoint inhibitor combined with other targeted or immunological therapy regimens for the treatment of advanced bile tract cancer: a systematic review and meta-analysis

Background and aims

A single immune checkpoint inhibitor (ICI) regimen has limited value in treating advanced bile tract cancer (BTC); therefore, ICI combination therapy is often applied. This meta-analysis aimed to evaluate the effectiveness and safety of ICI combination therapy for advanced BTC.

Methods

The study protocol was registered on PROSPERO (CRD42023452422). Data on the median progression-free survival (PFS), median overall survival (OS), objective response rate (ORR), disease control rate (DCR), and grade ≥3 adverse events (AEs) reported in relevant studies were pooled and analyzed to determine the efficacy and safety of ICI combination therapy.

Results

In total, 15 studies with 665 patients were included in this meta-analysis. The overall ORR and DCR were 34.6% and 77.6%, respectively. The overall median PFS and OS were 6.06 months [95% confidence interval (CI): 4.91-7.21] and 12.11 months (95% CI: 10.66-13.55), respectively. Patients receiving ICI combination therapy in addition to other therapies had a considerably prolonged median PFS and OS (z=9.69, p<0.001 and z=16.17, p<0.001). Patients treated as first-line treatment had a substantially longer median PFS and OS compared to patients treated as non-first-line treatment (z=11.19, p<0.001 and z=49.17, p<0.001). The overall pooled grade ≥3 AEs rate was 38.2% (95% CI: 0.268-0.497) and was not influenced by whether ICI therapy was combined with other treatments or not or the treatment line.

Conclusion

Advanced BTC patients may benefit from ICI combination treatment without additional AEs. However, concurrent chemotherapy or radiotherapy is still needed to achieve better outcomes.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023452422.

Evaluating the Therapeutic Potential of Durvalumab in Adults with Locally Advanced or Metastatic Biliary Tract Cancer: Evidence to Date

Advanced biliary tract cancers (BTCs) have historically been managed with chemotherapy but, in recent years, this treatment paradigm has begun to shift with the introduction of immune checkpoint inhibitors in addition to standard of care chemotherapy. The tumor microenvironment of BTC may be enriched with regulatory T lymphocytes and immune checkpoint expression in some patients. Durvalumab, an anti-programmed death ligand-1 (PD-L1) antibody, in combination with gemcitabine and cisplatin, has now received United States Food and Drug Administration approval for treatment of advanced BTC. Regulatory approval was based on the Phase III, randomized TOPAZ-1 trial that demonstrated survival benefit with addition of durvalumab to gemcitabine plus cisplatin compared to chemotherapy alone. The combination of chemotherapy and immunotherapy was well tolerated, and a subset of patients were able to achieve a durable response, with a 2-year overall survival rate of 23.6%. However, limitations remain in identifying which patients are most likely to benefit from immune checkpoint inhibition. Future study should aim to identify biomarkers predictive of substantial benefit, as well as the role of immune checkpoint inhibition in combination with targeted therapies and radiotherapy in the management of advanced BTC.

Emerging targeted therapies and strategies to overcome resistance in biliary tract cancers

In the last decade, targeted therapies have shown rapid advancement in biliary tract cancer (BTC). Today, many targeted agents are available and under investigation for patients with BTC. More recently, immune checkpoint inhibitors (ICI) such as durvalumab and pembrolizumab in combination with gemcitabine plus cisplatin (gem/cis) have resulted in improved overall survival and progression-free survival in the first-line setting. However, the efficacy benefit of these novel therapeutics is often short-lived, with literature outlining concerns about both primary and secondary resistance to these agents. Investigators also need to consider toxicity profiles that can emerge using this strategy. There have been efforts to reduce evolving resistance through combinatory approaches, both pre-clinically and in early clinical settings. This review summarizes the emerging targeted therapies in BTC, evolving biomarkers of resistance, strategies to overcome them, and an analysis of ongoing clinical trials of patients with advanced BTC.

Recent Advancement in Diagnosis of Biliary Tract Cancer through Pathological and Molecular Classifications

Biliary tract cancers (BTCs), including intrahepatic, perihilar, and distal cholangiocarcinomas, as well as gallbladder cancer, are a diverse group of cancers that exhibit unique molecular characteristics in each of their anatomic and pathological subtypes. The pathological classification of BTCs compromises distinct growth patterns, including mass forming, periductal infiltrating, and intraductal growing types, which can be identified through gross examination. The small-duct and large-duct types of intrahepatic cholangiocarcinoma have been recently introduced into the WHO classification. The presentation of typical clinical symptoms, as well as the extensive utilization of radiological, endoscopic, and molecular diagnostic methods, is thoroughly detailed in the description. To overcome the limitations of traditional tissue acquisition methods, new diagnostic modalities are being explored. The treatment landscape is also rapidly evolving owing to the emergence of distinct subgroups with unique molecular alterations and corresponding targeted therapies. Furthermore, we emphasize the crucial aspects of diagnosing BTC in practical clinical settings.

Fibroblast-Derived Lysyl Oxidase Increases Oxidative Phosphorylation and Stemness in Cholangiocarcinoma

BACKGROUND & AIMS

Metabolic and transcriptional programs respond to extracellular matrix-derived cues in complex environments, such as the tumor microenvironment. Here, we demonstrate how lysyl oxidase (LOX), a known factor in collagen crosslinking, contributes to the development and progression of cholangiocarcinoma (CCA).

METHODS

Transcriptomes of 209 human CCA tumors, 143 surrounding tissues, and single-cell data from 30 patients were analyzed. The recombinant protein and a small molecule inhibitor of the LOX activity were used on primary patient-derived CCA cultures to establish the role of LOX in migration, proliferation, colony formation, metabolic fitness, and the LOX interactome. The oncogenic role of LOX was further investigated by RNAscope and in vivo using the AKT/NICD genetically engineered murine CCA model.

RESULTS

We traced LOX expression to hepatic stellate cells and specifically hepatic stellate cell-derived inflammatory cancer-associated fibroblasts and found that cancer-associated fibroblast-driven LOX increases oxidative phosphorylation and metabolic fitness of CCA, and regulates mitochondrial function through transcription factor A, mitochondrial. Inhibiting LOX activity in vivo impedes CCA development and progression. Our work highlights that LOX alters tumor microenvironment-directed transcriptional reprogramming of CCA cells by facilitating the expression of the oxidative phosphorylation pathway and by increasing stemness and mobility.

CONCLUSIONS

Increased LOX is driven by stromal inflammatory cancer-associated fibroblasts and correlates with diminished survival of patients with CCA. Modulating the LOX activity can serve as a novel tumor microenvironment-directed therapeutic strategy in bile duct pathologies.

N6-methyladenosine-modified circSLCO1B3 promotes intrahepatic cholangiocarcinoma progression via regulating HOXC8 and PD-L1

BACKGROUND

Refractoriness to surgical resection and chemotherapy makes intrahepatic cholangiocarcinoma (ICC) a fatal cancer of the digestive system with high mortality and poor prognosis. Important function invests circRNAs with tremendous potential in biomarkers and therapeutic targets. Nevertheless, it is still unknown how circRNAs contribute to the evolution of ICC.

METHODS

CircRNAs in paired ICC and adjacent tissues were screened by circRNAs sequencing. To explore the impact of circRNAs on ICC development, experiments involving gain and loss of function were conducted. Various experimental techniques, including quantitative real-time PCR (qPCR), western blotting, RNA immunoprecipitation (RIP), luciferase reporter assays, RNA pull-down, chromatin immunoprecipitation (ChIP), ubiquitination assays and so on were employed to identify the molecular regulatory role of circRNAs.

RESULTS

Herein, we reported a new circRNA, which originates from exon 9 to exon 15 of the SLCO1B3 gene (named circSLCO1B3), orchestrated ICC progression by promoting tumor proliferation, metastasis and immune evasion. We found that the circSLCO1B3 gene was highly overexpressed in ICC tissues and related to lymphatic metastasis, tumor sizes, and tumor differentiation. Mechanically, circSLCO1B3 not only promoted ICC proliferation and metastasis via miR-502-5p/HOXC8/SMAD3 axis, but also eradicated anti-tumor immunity via suppressing ubiquitin-proteasome-dependent degradation of PD-L1 by E3 ubiquitin ligase SPOP. We further found that methyltransferase like 3 (METTL3) mediated the m6A methylation of circSLCO1B3 and stabilizes its expression. Our findings indicate that circSLCO1B3 is a potential prognostic marker and therapeutic target in ICC patients.

CONCLUSIONS

Taken together, m6A-modified circSLCO1B3 was correlated with poor prognosis in ICC and promoted ICC progression not only by enhancing proliferation and metastasis via potentiating HOXC8 expression, but also by inducing immune evasion via antagonizing PD-L1 degradation. These results suggest that circSLCO1B3 is a potential prognostic marker and therapeutic target for ICC.

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.

Treatment resistance in pancreatic and biliary tract cancer: molecular and clinical pharmacology perspectives

INTRODUCTION

Treatment resistance poses a significant obstacle in oncology, especially in biliary tract cancer (BTC) and pancreatic cancer (PC). Current therapeutic options include chemotherapy, targeted therapy, and immunotherapy. Resistance to these treatments may arise due to diverse molecular mechanisms, such as genetic and epigenetic modifications, altered drug metabolism and efflux, and changes in the tumor microenvironment. Identifying and overcoming these mechanisms is a major focus of research: strategies being explored include combination therapies, modulation of the tumor microenvironment, and personalized approaches.

AREAS COVERED

We provide a current overview and discussion of the most relevant mechanisms of resistance to chemotherapy, target therapy, and immunotherapy in both BTC and PC. Furthermore, we compare the different strategies that are being implemented to overcome these obstacles.

EXPERT OPINION

So far there is no unified theory on drug resistance and progress is limited. To overcome this issue, individualized patient approaches, possibly through liquid biopsies or single-cell transcriptome studies, are suggested, along with the potential use of artificial intelligence, to guide effective treatment strategies. Furthermore, we provide insights into what we consider the most promising areas of research, and we speculate on the future of managing treatment resistance to improve patient outcomes.

Genetic/Epigenetic Alteration and Tumor Immune Microenvironment in Intrahepatic Cholangiocarcinoma: Transforming the Immune Microenvironment with Molecular-Targeted Agents

Background

Intrahepatic cholangiocarcinoma (iCCA) is often diagnosed at an advanced stage, leading to limited treatment options and a poor prognosis. So far, standard systemic therapy for advanced iCCA has been a combination of gemcitabine and cisplatin. However, recent advancements in the understanding of the molecular characteristics of iCCA have opened new possibilities for molecular-targeted therapies and immunotherapy.

Summary

Reportedly, 9-36% of iCCA cases have an inflamed tumor immune microenvironment (TME) based on the immune gene expression signature, which is characterized by the presence of immune cells involved in anti-tumor immune responses. The majority of iCCA cases have a non-inflamed TME with a lack of effector T cells, rendering immune checkpoint inhibitors (ICIs) ineffective in these cases. Interestingly, alterations in the fibroblast growth factor receptor (FGFR2) gene and IDH1/2 gene mutations are often observed in the non-inflamed TME in iCCA. Several mechanisms have been reported for the role of driver mutations on the establishment of TME unique for iCCA. For example, IDH1/2 mutations, which cause an increase in DNA methylation, are associated with the downregulation and hypermethylation of antigen processing and presentation machinery, which may contribute to the establishment of a non-inflamed TME. Therefore, inhibitors targeting IDH1/2 may restore the DNA methylation and expression status of molecules involved in antigen presentation, potentially improving the efficacy of ICIs. FGFR inhibitors may also have the potential to modulate immunosuppressive TME by inhibitingthe suppressor of cytokine signaling 1 and activating the interferon-γ signaling as a consequence of inhibition of the FGFR signal. From this perspective, understanding the molecular characteristics of iCCA, including the TME and driver mutations, is essential for the effective application of ICIs and molecular-targeted therapies.

Key Messages

Combination approaches that target both the tumor and immune system hold promise for improving the outcomes of patients with iCCA. Further research and clinical trials are needed to validate these approaches and optimize the treatment strategies for iCCA.

Heterogeneity, crosstalk, and targeting of cancer-associated fibroblasts in cholangiocarcinoma

Cholangiocarcinoma (CCA) comprises diverse tumors of the biliary tree and is characterized by late diagnosis, short-term survival, and chemoresistance. CCAs are mainly classified according to their anatomical location and include diverse molecular subclasses harboring inter-tumoral and intratumoral heterogeneity. Besides the tumor cell component, CCA is also characterized by a complex and dynamic tumor microenvironment where tumor cells and stromal cells crosstalk in an intricate network of interactions. Cancer-associated fibroblasts, one of the most abundant cell types in the tumor stroma of CCA, are actively involved in cholangiocarcinogenesis by participating in multiple aspects of the disease including extracellular matrix remodeling, immunomodulation, neo-angiogenesis, and metastasis. Despite their overall tumor-promoting role, recent evidence indicates the presence of transcriptional and functional heterogeneous CAF subtypes with tumor-promoting and tumor-restricting properties. To elucidate the complexity and potentials of cancer-associated fibroblasts as therapeutic targets in CCA, this review will discuss the origin of cancer-associated fibroblasts, their heterogeneity, crosstalk, and role during tumorigenesis, providing an overall picture of the present and future perspectives toward cancer-associated fibroblasts targeting CCA.

Prognostic implications of tumor histology and microenvironment in surgically resected intrahepatic cholangiocarcinoma: a single institutional experience

Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive malignant neoplasm. Certain histologic features and the tumor microenvironment may impact disease progression. We aim to characterize the clinicopathologic features of ICC to identify prognostic factors. A total of 50 surgically resected ICC (partial or transplant) cases were analyzed. The cohort included 26 men and 24 women with a median age of 62 years. Eighteen (36%) cases were multifocal ICC with a mean largest tumor size of 6.5 cm. Neoadjuvant and adjuvant chemotherapy was done in eight (16%) and 33 (66%) patients, respectively. Histologically, 42 (84%) were small duct type, seven (14%) large duct type, and one mixed (2%). Thirty (60%) cases showed lymphovascular invasion (LVI) and 11 (22%) with perineural invasion (PNI). Twenty-eight (56%) cases demonstrated dense intratumoral hyaline fibrosis and 18 (36%) with tumor necrosis, each ≥ 10% tumor volume. On follow-up, 35 (70%) patients died of disease after a median disease-specific survival (DSS) of 21 months. Univariate analysis revealed that hyaline fibrosis and adjuvant chemotherapy were associated with better DSS, while tumor size, multifocality, necrosis, and peritumoral neutrophil to lymphocyte ratio were associated with worse DSS. In contrast, age, sex, small vs. large duct types, LVI, and individual inflammatory cell counts were not significant prognostic factors. In summary, ICC is a heterogeneous malignancy with variable clinical courses associated with tumor burden, histology, and microenvironment. Targeting specific components within the tumor microenvironments may be a promising approach for treatment in the future.

Immunotherapy for the treatment of biliary tract cancer: an evolving landscape

Biliary tract cancers (BTCs), consisting of intrahepatic and extrahepatic cholangiocarcinoma and gallbladder cancer, are an aggressive, heterogeneous malignancy. They are most often diagnosed in the locally advanced or metastatic setting, at which point treatment consists of systemic therapy or best supportive care. Our understanding of the tumor microenvironment and the molecular classification has led to the identification of targetable mutations, such as isocitrate dehydrogenase 1 and fibroblast growth factor receptor 2. Despite the identification of these genomic alterations, until recently, little advancement had been made in the first-line setting for advanced BTC. While immunotherapy (IO) has revolutionized the treatment of many malignancies, the use of IO in BTC had yielded limited results prior to TOPAZ-1. In this review, we discuss the systemic therapeutic advances for BTC over the past decade, the rationale for immunotherapy in BTC, prior trials utilizing IO in BTC, and current and emerging immune-based therapeutic options. We further analyze the culmination of these advances, which resulted in the approval of durvalumab with gemcitabine and cisplatin for the first-line treatment of BTC per TOPAZ-1. We also discuss the results of KEYNOTE-966, which similarly reported improved clinical outcomes with the use of pembrolizumab in combination with gemcitabine and cisplatin.

Molecular portraits of patients with intrahepatic cholangiocarcinoma who diverge as rapid progressors or long survivors on chemotherapy

OBJECTIVE

Cytotoxic agents are the cornerstone of treatment for patients with advanced intrahepatic cholangiocarcinoma (iCCA), despite heterogeneous benefit. We hypothesised that the pretreatment molecular profiles of diagnostic biopsies can predict patient benefit from chemotherapy and define molecular bases of innate chemoresistance.

DESIGN

We identified a cohort of advanced iCCA patients with comparable baseline characteristics who diverged as extreme outliers on chemotherapy (survival <6 m in rapid progressors, RP; survival >23 m in long survivors, LS). Diagnostic biopsies were characterised by digital pathology, then subjected to whole-transcriptome profiling of bulk and geospatially macrodissected tissue regions. Spatial transcriptomics of tumour-infiltrating myeloid cells was performed using targeted digital spatial profiling (GeoMx). Transcriptome signatures were evaluated in multiple cohorts of resected cancers. Signatures were also characterised using in vitro cell lines, in vivo mouse models and single cell RNA-sequencing data.

RESULTS

Pretreatment transcriptome profiles differentiated patients who would become RPs or LSs on chemotherapy. Biologically, this signature originated from altered tumour-myeloid dynamics, implicating tumour-induced immune tolerogenicity with poor response to chemotherapy. The central role of the liver microenviroment was confrmed by the association of the RPLS transcriptome signature with clinical outcome in iCCA but not extrahepatic CCA, and in liver metastasis from colorectal cancer, but not in the matched primary bowel tumours.

CONCLUSIONS

The RPLS signature could be a novel metric of chemotherapy outcome in iCCA. Further development and validation of this transcriptomic signature is warranted to develop precision chemotherapy strategies in these settings.

Case report: From palliative to potentially curative - the advent of immunotherapy providing hope to advanced gallbladder adenocarcinoma

Introduction

Biliary tract cancers (BTC) are often diagnosed at an advanced stage where prognosis is poor and curative-intent surgery is infeasible. First-line cisplatin-gemcitabine chemotherapy for advanced gallbladder cancer has remained unchanged over more than a decade, but recent developments in immunotherapy such as durvalumab have highlighted promise as a combination treatment regime with current standard chemotherapy.

Methods

In this case description, we present a case of locally-advanced gallbladder adenocarcinoma involving the biliary confluence that was initially planned for an extended right hepatectomy after portal vein embolization. Interval imaging revealed peritoneal metastasis, which was confirmed on diagnostic laparoscopy and biopsy. The patient underwent 8 cycles of cisplatin 25 mg/m2 and gemcitabine 1,000 mg/m2 chemotherapy on days 1 and 8 of each 21-day cycle, with durvalumab (Imfinzi®) 1,500 mg immunotherapy on day 1 of every cycle, in accordance with the treatment protocol of the TOPAZ-1 trial. Repeat imaging demonstrated a stable primary lesion with no further evidence of peritoneal disease. The patient subsequently underwent curative-intent conversion surgery with an extended right hepatectomy and Roux-en-Y hepaticojejunostomy, which were completed through a fully minimally-invasive laparoscopic approach.

Results

Final pathological TNM classification was ypT1aN0, with near-complete pathological response to pre-surgical therapy, uninvolved margins (R0 resection) and tumour shrinkage from 2.5 centimetres on pre-operative cross-sectional imaging to 0.5 centimetres on final histology. The patient had an uneventful post-operative course, and was fit for discharge by the fourth post-operative day. He remained well after three months of routine post-operative follow-up, with no significant post-operative complications and biochemical or radiological evidence of disease recurrence.

Conclusion

Our case description highlights the immense potential of combination durvalumab immunotherapy with cisplatin-gemcitabine chemotherapy in the treatment of advanced gallbladder adenocarcinoma. The patient's locally advanced disease was initially planned for complex open surgery, prior to discovery of peritoneal metastasis rendering it inoperable. This was successfully down-staged with combination therapy to eventual R0 resection via minimally-invasive surgery. In addition, this case description demonstrates the feasibility of a fully laparoscopic approach with postulated benefits of diagnostic re-evaluation of peritoneal disease, reduced wound pain and shorter length of hospital stay.

Combined immune checkpoint inhibition with durvalumab and tremelimumab with and without radiofrequency ablation in patients with advanced biliary tract carcinoma

BACKGROUND

Current standard of care for advanced biliary tract cancer (BTC) is gemcitabine, cisplatin plus anti-PD1/PD-L1, but response rates are modest. The purpose of this study was to explore the efficacy and safety of durvalumab (anti-PD-L1) and tremelimumab (anti-CTLA-4), with and without an interventional radiology (IR) procedure in advanced BTC.

METHODS

Eligible patients with advanced BTC who had received or refused at least one prior line of systemic therapy were treated with tremelimumab and durvalumab for four combined doses followed by monthly durvalumab alone with and without an IR procedure until the progression of disease or unacceptable toxicity. Objective response was assessed through CT or MRI by Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) every 8 weeks. Adverse events (AEs) were recorded and managed. The primary endpoint was 6-month progression-free survival (PFS).

RESULTS

Twenty-three patients with advanced BTC were enrolled; 17 patients were assigned to treatment with durvalumab and tremelimumab (Durva/Treme); and 6 patients were treated with the combination of durvalumab, tremelimumab plus IR procedure (Durva/Treme + IR). The best clinical responses in the Durva/Treme arm were partial response (n = 1), stable disease (n = 5), progressive disease (n = 5), and in the Durva/Treme + IR arm: partial response (n = 0), stable disease (n = 3), progressive disease (n = 3). The median PFS was 2.2 months (95% CI: 1.3-3.1 months) in the Durva/Treme arm and 2.9 months (95% CI: 1.9-4.7 months) in the Durva/Treme + IR arm (p = 0.27). The median OS was 5.1 months (95% CI: 2.5-6.9 months) in the Durva/Treme arm and 5.8 months (95% CI: 2.9-40.1 months) in the Durva/Treme + IR arm (p = 0.31). The majority of AEs were grades 1-2.

CONCLUSION

Durva/Treme and Durva/Treme + IR showed similar efficacy. With a manageable safety profile. Larger studies are needed to fully characterize the efficacy of Durva/Treme ± IR in advanced BTC.

Identification of the prognostic immune subtype in copy-number high endometrial cancer

OBJECTIVE

The TCGA molecular subtype of endometrial cancer (EC) is widely applied, among which the copy-number high (CNH) subtype has the poorest prognosis. However, the heterogeneity of this subtype remains elusive. In this study, we aimed to identify heterogeneous immune subtypes in CNH EC and explore their prognostic significance.

METHODS

We collected 60 CNH EC cases in the TCGA database and performed unsupervised cluster analysis based on the enrichment scores of immune-related gene signatures to identify immune subtypes. We described their immune characteristics and prognoses and conducted differential gene analysis and lasso regression to identify a prognostic biomarker, GZMM. For experimental validation, we performed immunohistochemical staining of GZMM in 39 p53-positive EC surgical samples.

RESULTS

We defined two immune subtypes, immune-hot (IH) and immune-cold (IC), which differed in immune cell infiltration, cytokine and chemokine expression and prognosis. The IH subtype has significantly stronger immune activation than the IC subtype, showing a significant infiltration of immune effector cells and high expression of relevant chemokines, with better prognosis. Moreover, the immunohistochemical staining of GZMM in a cohort of 39 p53-positive EC surgical samples confirmed GZMM as a unique prognostic biomarker, with high expression in both tumor cells and lymphocytes predicting a better prognosis.

CONCLUSION

Our study revealed heterogeneous immune subtypes in CNH EC and identified GZMM as a prognostic biomarker. The stratified classification strategy combining molecular and immune subtypes provides valuable insights for future clinical practice.

Pharmacokinetic Analysis of Prognostic Factors in Patients With Advanced-Stage Intrahepatic Cholangiocarcinoma Following the Administration of Capsule Formulation of the Standardized Extract of Atractylodes lancea (Thunb) DC

BACKGROUND

A statistical model is essential in determining the appropriate predictive indicators for therapies in many types of cancers. Predictors have been compared favorably to the traditional systems for many cancers. Thus, this study has been proposed as a new standard approach. A recent study on the clinical efficacy of Atractylodes lancea (Thunb) DC. (AL) revealed the higher clinical benefits in patients with advanced-stage intrahepatic cholangiocarcinoma (ICC) treated with AL compared with standard supportive care. We investigated the relationships between clinical efficacy and pharmacokinetic parameters of serum bioactivity of AL and its active constituent atractylodin and determined therapeutic ranges.

METHODS

Group 1 of advanced-stage ICC patients received daily doses of 1000 mg of standardized extract of the capsule formulation of AL (CMC-AL) for 90 days. Group 2 received daily doses of 1000 mg of CMC-AL for 14 days, followed by 1500 mg for 14 days, and 2000 mg for 62 days. Group 3 (control group) received palliative care. Cox proportional hazard model and Receiver Operating Characteristic (ROC) were applied to determine the cut-off values of AUC0-inf, Cmax, and Cavg associated with therapeutic outcomes. Number needed to treat (NNT) and relative risk (RR) were also applied to determine potential predictors.

RESULTS

The AUC0-inf of total AL bioactivity of >96.71 µg hour/ml was identified as a promising predictor of disease prognosis, that is, progression-free survival (PFS) and disease control rate (DCR). Cmax of total AL bioactivity of >21.42 was identified as a predictor of the prognosis of survival. The therapeutic range of total AL bioactivity for PFS and DCR is 14.48 to 65.8 µg/ml, and for overall survival is 10.97 to 65.8 µg/ml. Conclusions: The predictors of ICC disease prognosis were established based on the pharmacokinetics of total AL bioactivity. The information could be exploited to improve the clinical efficacy of AL in patients with advanced-stage ICC. These predictors will be validated in a phase 2B clinical study.

TRIAL REGISTRATION

TCTR20210129007 (TCTR: www.clinicaltrials.in.th).

Case Report: A novel mixture of dose-fractioned radiation and immunotherapy for treatment of cholangiocarcinoma

Malignant tumors of the biliary tract exhibit a high degree of malignancy and heterogeneity with a poor overall prognosis. Immunotherapy has limited benefits for patients with cholangiocarcinoma. Radiation therapy can change the tumor microenvironment, but its effect heavily depends on radiation dose and fraction. We report a case of advanced intrahepatic cholangiocarcinoma in a 43-year-old male patient, with a huge liver mass of 16.5 cm in diameter, with bone and liver metastases at the first diagnosis. First-line treatment with chemotherapy and PD1 inhibitor was sustained only for 8 months. In second-line treatment, radiotherapy was administered, with 5 Gy in 5 fractions administered to the entire tumor area and 25 Gy in 5 fractions to the solid lesions of the tumor. After the completion of radiotherapy, programmed cell death 1 inhibitor combined with tyrosine kinase inhibitor was maintained. The patient achieved a progression-free-survival time of 12 months and an overall survival time of 25 months. The success of our case suggests that mixed low- and high-dose radiation can significantly improve tumor control and survival time. In clinical practice, based on the characteristics of the tumor and existing treatment options, the rational combination of existing treatment regimens can improve the prognosis of cholangiocarcinoma.

Tumor immune microenvironment and the current immunotherapy of cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a highly heterogeneous malignancy originating from the epithelial system of the bile ducts, and its incidence in recent years is steadily increasing. The immune microenvironment of CCA is characterized by diversity and complexity, with a substantial presence of cancer‑associated fibroblasts and immune cell infiltration, which plays a key role in regulating the distinctive biological behavior of cholangiocarcinoma, including tumor growth, angiogenesis, lymphangiogenesis, invasion and metastasis. Despite the notable success of immunotherapy in the treatment of solid tumors in recent years, patients with CCA have responded poorly to immune checkpoint inhibitor therapy. The interaction of tumor cells with cellular components of the immune microenvironment can regulate the activity and function of immune cells and form an immunosuppressive microenvironment, which may cause ineffective immunotherapy. Therefore, the components of the tumor immune microenvironment appear to be novel targets for immune therapies. Combination therapy focusing on immune checkpoint inhibitors is a promising and valuable first‑line or translational treatment approach for intractable biliary tract malignancies. The present review discusses the compositional characteristics and regulatory factors of the CCA immune microenvironment and the possible immune escape mechanisms. In addition, a summary of the advances in immunotherapy for CCA is also provided. It is hoped that the present review may function as a valuable reference for the development of novel immunotherapeutic strategies for CCA.

Exploration of a screening model for intrahepatic cholangiocarcinoma patients prone to cuproptosis and mechanisms of the susceptibility of CD274-knockdown intrahepatic cholangiocarcinoma cells to cuproptosis

Intrahepatic cholangiocarcinoma (ICC) is a form of liver cancer with poor long-term survival rates that requires novel therapeutic methods. Our team's previous research found that ICC patients prone to cuproptosis possessed a more satisfactory long-term prognosis and a more sensitive response to copper carrier Elesclomol. Thus, we aimed to identify new diagnostic and treatment strategies for ICC patients prone to cuproptosis and further explore the associated intracellular and extracellular mechanisms of ICC cells prone to cuproptosis. We employed FU-ICC (n = 255) as the training dataset, and validated our findings using SRRSH-ICC (from our center, n = 65), GSE26566 (n = 104), E-MTAB-6389 (n = 78), and scRNA-seq (n = 14) datasets. Single sample gene set enrichment analysis and subsequent unsupervised cluster analysis was conducted on the training dataset for the pan-programmed cell death gene set (including apoptosis, autophagy, ferroptosis, pyroptosis, necroptosis, and cuproptosis) to define and screen ICC patients prone to cuproptosis. We constructed a nomogram model using weighted gene co-expression network analysis and machine learning algorithms to predict ICC patients prone to cuproptosis, then explored its clinical value with multi-center transcriptome profiling. Furthermore, we validated the hub genes with in vitro and animal experiments to define ICC cells prone to cuproptosis. Ultimately, bulk and single-cell transcriptome profiling were utilized to explore the immune microenvironment of ICC cells prone to cuproptosis. Our nomogram model could help predict ICC patients prone to cuproptosis and possessed excellent prediction efficiency and clinical significance via internal and external verification. In vitro experiments demonstrated that ICC cells with siRNA-mediated knockdown of CD274 (PD-L1) and stimulation with elescomol-CuCl2 were prone to cuproptosis, and CD274-negative ICC cells could be defined as ICC cells prone to cuproptosis. The safety and feasibility of lenti-sh CD274+Elesclomol-CuCl2 as a therapeutic approach for ICC were verified using bioinformatics analysis and animal experiments. Bulk and single-cell transcriptome profiling indicated that the interactions between ICC cells prone to cuproptosis and monocytes/macrophages were particularly relevant. In conclusion, this study systematically and comprehensively explored cuproptosis in ICC for the first time. We constructed precise diagnostic and treatment strategies for ICC patients prone to cuproptosis and further explored the intracellular and extracellular mechanisms of ICC cells prone to cuproptosis. Further work with large prospective cohorts will help verify these conclusions.

Immunogenomics of cholangiocarcinoma

The development of cholangiocarcinoma spans years, if not decades, during which the immune system becomes corrupted and permissive to primary tumor development and metastasis. This involves subversion of local immunity at tumor sites, as well as systemic immunity and the wider host response. While immune dysfunction is a hallmark of all cholangiocarcinoma, the specific steps of the cancer-immunity cycle that are perturbed differ between patients. Heterogeneous immune functionality impacts the evolutionary development, pathobiological behavior, and therapeutic response of these tumors. Integrative genomic analyses of thousands of primary tumors have supported a biological rationale for immune-based stratification of patients, encompassing immune cell composition and functionality. However, discerning immune alterations responsible for promoting tumor initiation, maintenance, and progression from those present as bystander events remains challenging. Functionally uncoupling the tumor-promoting or tumor-suppressing roles of immune profiles will be critical for identifying new immunomodulatory treatment strategies and associated biomarkers for patient stratification. This review will discuss the immunogenomics of cholangiocarcinoma, including the impact of genomic alterations on immune functionality, subversion of the cancer-immunity cycle, as well as clinical implications for existing and novel treatment strategies.

A pan-cancer analysis of the MAPK family gene and their association with prognosis, tumor microenvironment, and therapeutic targets

The mitogen-activated protein kinases family of genes plays a crucial role in a wide range of inflammatory responses in the human body. The MAPK family of genes includes ERK, ERK5, JNK, P-38 mitogen-activated protein kinases. However, the correlation between MAPK family gene expression and pan-cancer prognosis, as well as the tumor microenvironment, has not been extensively studied. This study integrated multiple bioinformatics analysis methods to assess the expression and prognostic value of MAPK family genes, as well as their relationship with tumor microenvironment in patients with pan-cancer. The results showed that ERK, JNK, and P-38 MAPK expression were found to be significantly upregulated in rectum adenocarcinoma (READ), colon adenocarcinoma/rectum adenocarcinoma esophageal carcinoma (COADREAD), and kidney renal clear cell carcinoma (KIRC), and significantly downregulated in acute myeloid leukemia. And the results revealed good prognostic results for ERK, JNK, and P-38 MAPK in READ, COADREAD, and KIRC. We observed significant positive correlation between MAPK family gene expression and immune scores especially dendritic cells in READ, COADREAD, and KIRC. And we observed that the expression levels of MAPK family genes were significantly correlated with the expression of immune-related genes, such as CXCL1, CXCL2, CXCL8, CXCR1, CXCR2, CTLA-4, CD80, CD86, and CD28, suggesting their important role in regulating immune infiltrates and tumor progression. Therefore, our study suggested that MAPK family gene plays an important role in regulating immune infiltrates and tumor progression.

Real-world cohort study of PD-1 blockade plus lenvatinib for advanced intrahepatic cholangiocarcinoma: effectiveness, safety, and biomarker analysis

BACKGROUND

In clinical practice, some patients with advanced intrahepatic cholangiocarcinoma (ICC) cannot tolerate or refuse chemotherapy due to the toxicity, necessitating alternative treatments. PD-1 blockade combined with lenvatinib showed promising results in phase II studies with small sample size, but there is a lack of data on the routine use with this regimen. This study aimed to evaluate the effectiveness and safety of the regimen in patients with advanced ICC, and to identify predictors for treatment response and prognosis.

METHODS

We conducted a retrospective cohort study of patients treated with PD-1 inhibitors plus lenvatinib for advanced ICC between July 2017 and August 2022. The study endpoints were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. Biomarker analysis for CA19-9 and PD-L1 expression was performed. Exploratory analysis for genetic alternation was conducted.

RESULTS

The study included 103 patients. It demonstrated a median PFS of 5.9 months and a median OS of 11.4 months. ORR was 18.4% and DCR was 80.6%. The incidence of grade 3 or 4 adverse events was 50.5%. Positive PD-L1 expression (TPS ≥ 1%) was associated with higher ORR (P = 0.013) and prolonged PFS (P = 0.023). Elevated CA19-9 (> 37 U/ml) was associated with decreased ORR (P = 0.019), poorer PFS (P = 0.005) and OS (P = 0.034). Patients with IDH1 mutations exhibited a favorable response to the treatment (P = 0.011), and patients with TP53 mutations tended to have worse OS (P = 0.031).

CONCLUSIONS

PD-1 blockade plus lenvatinib is effective and safe in routine practice. PD-L1 expression and CA19-9 level appear to predict the treatment efficacy. IDH1 mutations might indicate a better treatment response.

CLINICAL TRIAL REGISTRATION

NCT03892577.

Using immunovascular characteristics to predict very early recurrence and prognosis of resectable intrahepatic cholangiocarcinoma

OBJECTIVE

To predict the very early recurrence (VER) of patients with intrahepatic cholangiocarcinoma (ICC) based on TLSs and MVI status, and further perform prognosis stratifications.

METHODS

A total of 160, 51 ICC patients from two institutions between May 2012 and July 2022 were retrospectively included as training, external validation cohort. Clinical, radiological and pathological variables were evaluated and collected. Univariate and multivariate analysis were applied to select the significant factors related to VER of ICC. The factors selected were combined to perform stratification of overall survival (OS) using the Kaplan-Meier method with the log-rank test.

RESULTS

Overall, 39 patients (24.4%) had VER, whereas 121 (75.6%) did not (non-VER group). In the training cohort, the median OS was 40.5 months (95% CIs: 33.2-47.7 months). The VER group showed significantly worse OS than the non-VER group (median OS: 14.8, 95% CI:11.6-18.0 months vs. 53.4, 34.3-72.6 months; p<0.001), and it was confirmed in the validation cohort (median OS: 22.1, 95% CI: 8.8-35.4 months vs. 40.1, 21.2-59.0 months; p = 0.003). According to the univariate analysis, four variables were significantly different between the VER group and non-VER group (TLSs status, p = 0.028; differentiation, p = 0.023; MVI status, p = 0.012; diameter, p = 0.028). According to the multivariate analysis, MVI-positive status was independently associated with a higher probability of VER (odds ratio [OR], 2.5; 95% CIs,1.16-5.18; p = 0.018), whereas intra-tumoral TLSs-positive status was associated with lower odds of VER (OR, 0.43; 95% CIs, 0.19-0.97; p = 0.041). Based on the TLSs and MVI status, patients of ICC were categorized into four groups: TLSs-positive and MVI-negative (TP/MN); TLSs-negative and MVI-negative (TN/MN); TLSs-positive and MVI-positive (TP/MP), TLSs-negative and MVI-positive groups (TN/MP). In the training cohort, the four groups could be correlated with OS significantly (p<0.001), and it was confirmed in the validation cohort (p<0.001).

CONCLUSION

Intra-tumoral TLSs and MVI status are independent predictive factors of VER after surgery, based on which immunovascular stratifications are constructed and associated with OS significantly of resectable intrahepatic cholangiocarcinoma.

Translating imaging traits of mass-forming intrahepatic cholangiocarcinoma into the clinic: From prognostic to therapeutic insights

Background & Aims

The progress toward clinical translation of imaging biomarkers for mass-forming intrahepatic cholangiocarcinoma (MICC) is slower than anticipated. Questions remain on the biologic behaviour underlying imaging traits. We developed and validated imaging-based prognostic systems for resected MICCs with an appraisal of the tumour immune microenvironment (TIME) underpinning patient-specific imaging traits.

Methods

Between January 2009 and December 2019, a total of 322 patients who underwent dynamic computed tomography/magnetic resonance imaging and curative-intent resection for MICC at three hepatobiliary institutions were retrospectively recruited, divided into training (n = 193) and validation (n = 129) datasets. Two radiological and clinical scoring (RACS) systems, one integrating preoperative variables and one integrating preoperative and postoperative variables, were developed using Cox regression analysis. We then prospectively analysed the TIME of tissue samples from 20 patients who met study criteria from January 2021 to December 2021 using multiplexed immunofluorescence.

Results

Preoperative and postoperative MICC-RACS systems built on carbohydrate antigen 19-9, albumin, tumour number, radiological/pathological nodal status, pathological necrosis, and three radiological traits (arterial enhancement pattern, tumour boundary, and capsular retraction) demonstrated good performance in predicting disease-specific (C-statistic >0.80) and disease-free (C-statistic >0.75) survival that outperformed rival models and staging systems across study cohorts (P <0.05 for all). Patients with MICC-RACS score of 0-2 (low risk), 3-5 (medium risk), and ≥6 (high risk) had incrementally worse prognosis after surgery. Significant differences in spatial distribution and infiltration level of immune cells were identified between arterial enhancement patterns. Enhanced infiltration of immunosuppressive regulatory T cells and M2-like macrophages at the invasive margin were noted in tumours with distinct boundary and capsular retraction, respectively.

Conclusions

Our MICC-RACS systems are simple but powerful prognostic tools that may facilitate the understanding of spatially distinct TIMEs and patient-tailored immunotherapy approach.

Impact and Implications

The progress toward clinical translation of imaging biomarkers for mass-forming intrahepatic cholangiocarcinoma (MICC) is slower than anticipated. Questions remain on the biologic behaviour of MICC underlying imaging traits. In this study, we proposed novel and easy-to-use tools, built on radiological and clinical features, that demonstrated good performance in predicting the prognosis either before or after surgery and outperformed rival models/systems across major imaging modalities. The characteristic radiological traits integrated into prognostic systems (arterial enhancement pattern, tumour boundary, and capsular retraction) were highly correlated with heterogeneous tumour-immune microenvironments, thereby renovating treatment paradigms for this difficult-to-treat disease.

Friend or foe? The elusive role of hepatic stellate cells in liver cancer

Liver fibrosis is a substantial risk factor for the development and progression of liver cancer, which includes hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Studies utilizing cell fate mapping and single-cell transcriptomics techniques have identified quiescent perisinusoidal hepatic stellate cells (HSCs) as the primary source of activated collagen-producing HSCs and liver cancer-associated fibroblasts (CAFs) in HCC and liver metastasis, complemented in iCCA by contributions from portal fibroblasts. At the same time, integrative computational analysis of single-cell, single-nucleus and spatial RNA sequencing data have revealed marked heterogeneity among HSCs and CAFs, with distinct subpopulations displaying unique gene expression signatures and functions. Some of these subpopulations have divergent roles in promoting or inhibiting liver fibrogenesis and carcinogenesis. In this Review, we discuss the dual roles of HSC subpopulations in liver fibrogenesis and their contribution to liver cancer promotion, progression and metastasis. We review the transcriptomic and functional similarities between HSC and CAF subpopulations, highlighting the pathways that either promote or prevent fibrosis and cancer, and the immunological landscape from which these pathways emerge. Insights from ongoing studies will yield novel strategies for developing biomarkers, assessing prognosis and generating new therapies for both HCC and iCCA prevention and treatment.

Immunobiology of cholangiocarcinoma

Recent literature has significantly advanced our knowledge and understanding of the tumour immune microenvironment of cholangiocarcinoma. Detailed characterisation of the immune landscape has defined new patient subtypes. While not utilised in clinical practice yet, these novel classifications will help inform decisions regarding immunotherapeutic approaches. Suppressive immune cells, such as tumour-associated macrophages and myeloid-derived suppressor cells, form a barrier that shields tumour cells from immune surveillance. The presence of this immunosuppressive barrier in combination with a variety of immune escape mechanisms employed by tumour cells leads to poor tumour immunogenicity. Broad strategies to re-equip the immune system include blockade of suppressive immune cell recruitment to priming cytotoxic effector cells against tumour antigens. While immunotherapeutic strategies are gaining traction for the treatment of cholangiocarcinoma, there is a long road of discovery ahead in order to make meaningful contributions to patient therapy and survival.

Classification of Brainstem Gliomas Based on Tumor Microenvironment Status

The inter-tumor heterogeneity of the tumor microenvironment (TME) and how it correlates with clinical profiles and biological characteristics in brainstem gliomas (BSGs) remain unknown, dampening the development of novel therapeutics against BSGs. The TME status was determined with a list of pan-cancer conserved gene expression signatures using a single-sample gene set enrichment analysis (ssGSEA) and was subsequently clustered via consensus clustering. BSGs exhibited a high inter-tumor TME heterogeneity and were classified into four clusters: "immune-enriched, fibrotic", "immune-enriched, non-fibrotic", "fibrotic", and "depleted". The "fibrotic" cluster had a higher proportion of diffuse intrinsic pontine gliomas (p = 0.041), and "PA-like" tumors were more likely to be "immune-enriched, fibrotic" (p = 0.044). The four TME clusters exhibited distinct overall survival (p < 0.001) and independently impacted BSG outcomes. A four-gene panel as well as a radiomics approach were constructed to identify the TME clusters and achieved high accuracy for determining the classification. Together, BSGs exhibited high inter-tumor heterogeneity in the TME and were classified into four clusters with distinct clinical outcomes and tumor biological properties. The TME classification was accurately identified using a four-gene panel that can potentially be examined with the immunohistochemical method and a non-invasive radiomics method, facilitating its clinical application.

Radiomic Analysis of Intrahepatic Cholangiocarcinoma: Non-Invasive Prediction of Pathology Data: A Multicenter Study to Develop a Clinical-Radiomic Model

Standard imaging cannot assess the pathology details of intrahepatic cholangiocarcinoma (ICC). We investigated whether CT-based radiomics may improve the prediction of tumor characteristics. All consecutive patients undergoing liver resection for ICC (2009-2019) in six high-volume centers were evaluated for inclusion. On the preoperative CT, we segmented the ICC (Tumor-VOI, i.e., volume-of-interest) and a 5-mm parenchyma rim around the tumor (Margin-VOI). We considered two types of pathology data: tumor grading (G) and microvascular invasion (MVI). The predictive models were internally validated. Overall, 244 patients were analyzed: 82 (34%) had G3 tumors and 139 (57%) had MVI. For G3 prediction, the clinical model had an AUC = 0.69 and an Accuracy = 0.68 at internal cross-validation. The addition of radiomic features extracted from the portal phase of CT improved the model performance (Clinical data+Tumor-VOI: AUC = 0.73/Accuracy = 0.72; +Tumor-/Margin-VOI: AUC = 0.77/Accuracy = 0.77). Also for MVI prediction, the addition of portal phase radiomics improved the model performance (Clinical data: AUC = 0.75/Accuracy = 0.70; +Tumor-VOI: AUC = 0.82/Accuracy = 0.73; +Tumor-/Margin-VOI: AUC = 0.82/Accuracy = 0.75). The permutation tests confirmed that a combined clinical-radiomic model outperforms a purely clinical one (p < 0.05). The addition of the textural features extracted from the arterial phase had no impact. In conclusion, the radiomic features of the tumor and peritumoral tissue extracted from the portal phase of preoperative CT improve the prediction of ICC grading and MVI.

Epigenetic deregulation of MLF1 drives intrahepatic cholangiocarcinoma progression through EGFR/AKT and Wnt/β-catenin signaling

BACKGROUND

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive malignancy with multiple etiologies and is largely refractory to current treatment strategies. Myeloid leukemia factor 1 (MLF1) is associated with human cancer progression. Nevertheless, the function of MLF1 in iCCA remains unknown.

METHODS

We performed expression analyses of MLF1 in human iCCA. In vitro and in vivo experiments were conducted to investigate the role of MLF1 in iCCA progression. The upstream regulatory mechanism of MLF1 upregulation in iCCA was deciphered by luciferase and DNA methylation analyses.

RESULTS

MLF1 was significantly upregulated in clinical iCCA tissue specimens and human iCCA cell lines. MLF1 was positively correlated with KRT19 and MUC1 expression and epithelial-mesenchymal transition (EMT) gene set enrichment score in clinical iCCA. High MLF1 expression was independently associated with worse prognoses in iCCA patients after curative resection. In addition, experimental knockdown of MLF1 attenuated, while overexpression of MLF1 promoted the proliferation, invasiveness, and growth of iCCA cells in vitro and in vivo. Mechanically, MLF1 comodulated EGFR/AKT and Wnt/β-catenin signalings through regulating EGFR, AKT, WNT3, and p-GSK3β expression. Promoter CpG sites' hypermethylation-induced downregulation of miR-29c-3p contributed to MLF1 upregulation in iCCA patients. The upregulation of DNA methyltransferase (DNMT)1, 3A, and 3B downregulated miR-29c-3p by dictating promoter DNA methylation pattern. MiR-29c-3p showed therapeutic potential by targeting MLF1 in iCCA.

CONCLUSIONS

Our results demonstrated that hypermethylation-mediated miR-29c-3p downregulation contributes to MLF1 upregulation in iCCA, which resulted in tumor cells' proliferation and metastasis through comodulating EGFR/AKT and Wnt/β-catenin signalings.

Spatial immunophenotypes predict clinical outcome in intrahepatic cholangiocarcinoma

Background & Aims

Intrahepatic cholangiocarcinoma (iCCA) is a severe malignant tumour that shows only modest responses to immunotherapy. We aimed to identify the spatial immunophenotypes of iCCA and delineate potential immune escape mechanisms.

Method

Multiplex immunohistochemistry (mIHC) was performed to quantitatively evaluate the distribution of 16 immune cell subsets in intratumour, invasive margin and peritumour areas in a cohort of 192 treatment-naïve patients with iCCA. Multiregion unsupervised clustering was used to determine three spatial immunophenotypes, and multiomics analyses were carried out to explore functional differences.Results: iCCA displayed a region-specific distribution of immune cell subsets with abundant CD15⁺ neutrophil infiltration in intratumour areas. Three spatial immunophenotypes encompassing inflamed (35%), excluded (35%) and ignored (30%) phenotypes were identified. The inflamed phenotype showed characteristics of abundant immune cell infiltration in intratumour areas, increased PD-L1 expression and relatively favourable overall survival. The excluded phenotype with a moderate prognosis was characterized by immune cell infiltration restricted to the invasive margin or peritumour areas and upregulation of activated hepatic stellate cells, extracellular matrix and Notch signalling pathways. The ignored phenotype, with scarce immune cell infiltration across all subregions, was associated with MAPK signalling pathway elevation and a poor prognosis. The excluded and ignored phenotypes, constituting non-inflamed phenotypes, shared features of an increased angiogenesis score, TGF-β and Wnt-β catenin pathway upregulation and were enriched for BAP1 mutations and FGFR2 fusions.

Conclusion

We identified three spatial immunophenotypes with different overall prognoses in iCCA. Tailored therapies based on the distinct immune evasion mechanisms of the spatial immunophenotypes are needed.

Impact and implications

The contribution of immune cell infiltration in the invasive margin and peritumour areas has been proved. We explored the multiregional immune contexture of 192 patients to identify three spatial immunophenotypes in intrahepatic cholangiocarcinoma (iCCA). By integrating genomic and transcriptomic data, phenotype-specific biological behaviours and potential immune escape mechanisms were analysed. Our findings provide a rationale to develop personalized therapies for iCCA.

Genetic polymorphisms in interleukin-1β (rs1143634) and interleukin-8 (rs4073) are associated with survival after resection of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a rare, understudied primary hepatic malignancy with dismal outcomes. Aiming to identify prognostically relevant single-nucleotide polymorphisms, we analyzed 11 genetic variants with a role in tumor-promoting inflammation (VEGF, EGF, EGFR, IL-1B, IL-6, CXCL8 (IL-8), IL-10, CXCR1, HIF1A and PTGS2 (COX-2) genes) and their association with disease-free (DFS) and overall survival (OS) in patients undergoing curative-intent surgery for iCCA. Genomic DNA was isolated from 112 patients (64 female, 48 male) with iCCA. Germline polymorphisms were analyzed with polymerase chain reaction-restriction fragment length polymorphism protocols. The IL-1B +3954 C/C (73/112, hazard ratio (HR) = 1.735, p = 0.012) and the IL-8 -251 T/A or A/A (53/112 and 16/112, HR = 2.001 and 1.1777, p = 0.026) genotypes were associated with shorter OS in univariable and multivariable analysis. The IL-1B +3954 polymorphism was also associated with shorter DFS (HR = 1.983, p = 0.012), but this effect was not sustained in the multivariable model. A genetic risk model of 0, 1 and 2 unfavorable alleles was established and confirmed in multivariable analysis. This study supports the prognostic role of the IL-1B C+3954T and the IL-8 T-251A variant as outcome markers in iCCA patients, identifying patient subgroups at higher risk for dismal clinical outcomes.

Preclinical and clinical studies of immunotherapy for the treatment of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a rare primary liver cancer associated with high mortality and few systemic treatment options. The behaviour of the immune system has come into focus as a potential treatment modality for many cancer types, but immunotherapy has yet to dramatically alter the treatment paradigm for CCA as it has for other diseases. Herein, we review recent studies describing the relevance of the tumour immune microenvironment (TIME) in CCA. Various non-parenchymal cell types are critically important in controlling CCA progression, prognosis, and response to systemic therapy. Knowledge of the behaviour of these leukocytes could help generate hypotheses to guide the development of potential immune-directed therapies. Recently, an immunotherapy-containing combination was approved for the treatment of advanced-stage CCA. However, despite level 1 evidence demonstrating the improved efficacy of this therapy, survival remained suboptimal. In the current manuscript, we provide a comprehensive review of the TIME in CCA, preclinical studies of immunotherapies against CCA, as well as ongoing clinical trials applying immunotherapies for the treatment of CCA. Particular emphasis is placed on microsatellite unstable tumours, a rare CCA subtype that demonstrates heightened sensitivity to approved immune checkpoint inhibitors. We also discuss the challenges involved in applying immunotherapies to the treatment of CCA and the importance of understanding the TIME.

Cholangiocarcinoma - novel biological insights and therapeutic strategies

In the past 5 years, important advances have been made in the scientific understanding and clinical management of cholangiocarcinoma (CCA). The cellular immune landscape of CCA has been characterized and tumour subsets with distinct immune microenvironments have been defined using molecular approaches. Among these subsets, the identification of 'immune-desert' tumours that are relatively devoid of immune cells emphasizes the need to consider the tumour immune microenvironment in the development of immunotherapy approaches. Progress has also made in identifying the complex heterogeneity and diverse functions of cancer-associated fibroblasts in this desmoplastic cancer. Assays measuring circulating cell-free DNA and cell-free tumour DNA are emerging as clinical tools for detection and monitoring of the disease. Molecularly targeted therapy for CCA has now become a reality, with three drugs targeting oncogenic fibroblast growth factor receptor 2 (FGFR2) fusions and one targeting neomorphic, gain-of-function variants of isocitrate dehydrogenase 1 (IDH1) obtaining regulatory approval. By contrast, immunotherapy using immune-checkpoint inhibitors has produced disappointing results in patients with CCA, underscoring the requirement for novel immune-based treatment strategies. Finally, liver transplantation for early stage intrahepatic CCA under research protocols is emerging as a viable therapeutic option in selected patients. This Review highlights and provides in-depth information on these advances.

Immunotherapy in Biliary Tract Cancers: Current Standard-of-Care and Emerging Strategies

Biliary tract cancers (BTCs), comprising intrahepatic, perihilar, and distal cholangiocarcinoma as well as gallbladder adenocarcinoma, continue to be challenging to manage. Conventional chemotherapy regimens for advanced disease are limited in both options and benefits, and more effective perioperative regimens are also needed. Over the last decade, immunotherapy has had a profound impact on the management of many solid tumor types, particularly in using immune checkpoint inhibition to enable a tumor-directed T cell response. Immunotherapy administered on its own has had limited utility in BTCs, in part due to a hostile immune microenvironment and the relative infrequency of biomarker-based tumor-agnostic indications for immunotherapy. However, immunotherapy in conjunction with chemotherapy, molecularly targeted therapies, and/or anti-angiogenic therapies has gained traction, supported by evidence that these agents can impart favorable immunomodulatory effects on the tumor microenvironment. The TOPAZ-1 trial led to the first BTC-specific immunotherapy approval, establishing the combination of durvalumab with gemcitabine and cisplatin as the preferred first-line treatment for advanced or metastatic disease. Recently, the KEYNOTE-966 trial showed positive results for the combination of pembrolizumab with gemcitabine and cisplatin in the same setting, adding further evidence for the addition of immune checkpoint inhibition to the standard chemotherapy backbone. Meanwhile, advances in the molecular profiling of BTCs has contributed to the recent proliferation of molecularly targeted therapeutics for the subset of BTCs harboring alterations in IDH1, FGFR2, MAP kinase signaling, HER2, and beyond, and there has been great interest in investigating combinations of these agents with immunotherapy. Emerging immunotherapy strategies beyond immune checkpoint inhibition are also being studied in BTCs, and these include immunostimulatory receptor agonists, Wnt signaling modulators, adoptive cell therapy, and cancer vaccines. A large number of trials are underway to explore promising new combinations and immune-targeted strategies, offering opportunities to expand the role of immunotherapy in BTC management in the near future.

Preoperative immunological plasma markers TRAIL, CSF1 and TIE2 predict survival after resection for biliary tract cancer

Introduction

Systemic inflammatory markers have been validated as prognostic factors for patients with biliary tract cancer (BTC). The aim of this study was to evaluate specific immunologic prognostic markers and immune responses by analyzing preoperative plasma samples from a large prospectively collected biobank.

Methods

Expression of 92 proteins representing adaptive and innate immune responses was investigated in plasma from 102 patients undergoing resection for BTC 2009-2017 (perihilar cholangiocarcinoma n=46, intrahepatic cholangiocarcinoma n=27, gallbladder cancer n=29), by means of a high-throughput multiplexed immunoassay. Association with overall survival was analyzed by Cox regression, with internal validation and calibration. Tumor tissue bulk and single-cell gene expression of identified markers and receptors/ligands was analyzed in external cohorts.

Results

Three preoperative plasma markers were independently associated with survival: TRAIL, TIE2 and CSF1, with hazard ratios (95% confidence intervals) 0.30 (0.16-0.56), 2.78 (1.20-6.48) and 4.02 (1.40-11.59) respectively. The discrimination of a preoperative prognostic model with the three plasma markers was assessed with concordance-index 0.70, while the concordance-index of a postoperative model with histopathological staging was 0.66. Accounting for subgroup differences, prognostic factors were assessed for each type of BTC. TRAIL and CSF1 were prognostic factors in intrahepatic cholangiocarcinoma. In independent cohorts, TRAIL-receptor expression was higher in tumor tissue and seen in malignant cells, with TRAIL and CSF1 expressed by intra- and peritumoral immune cells. Intratumoral TRAIL-activity was decreased compared to peritumoral immune cells, while CSF1-activity was increased. The highest CSF1 activity was seen in intratumoral macrophages, while the highest TRAIL-activity was seen in peritumoral T-cells.

Discussion

In conclusion, three preoperative immunological plasma markers were prognostic for survival after surgery for BTC, providing good discrimination, even compared to postoperative pathology. TRAIL and CSF1, prognostic factors in intrahepatic cholangiocarcinoma, showed marked differences in expression and activity between intra- and peritumoral immune cells.

Cholangiocarcinoma in the Era of Immunotherapy

Cholangiocarcinoma (CCA) is a rare malignancy of the gastrointestinal tract, with aggressive behavior, and portends a poor prognosis. Traditionally, it is classified according to its site of involvement as intrahepatic, perihilar, and distal cholangiocarcinoma. A host of genetic and epigenetic factors have been involved in its pathogenesis. Chemotherapy has remained the standard first-line treatment over the last decade, with a disappointing median overall survival of 11 months for locally advanced and metastatic CCA. The advent of immunotherapy has revolutionized the treatment of many pancreaticobiliary malignancies, offering durable responses with a safe therapeutic profile. To date, there have been no significant advances in the management of CCA. Novel immunotherapeutic methods, such as cancer vaccines, adoptive cell therapy, and combinations of immune checkpoint inhibitors with other agents, are currently under investigation and may improve prognosis with overall survival. Efforts to find robust biomarkers for response to treatment along with multiple clinical trials are also ongoing in this regard. In this review, we present an overview of the current advances and the future perspectives of immunotherapy in the management of CCA.

Pembrolizumab in combination with gemcitabine and cisplatin compared with gemcitabine and cisplatin alone for patients with advanced biliary tract cancer (KEYNOTE-966): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Biliary tract cancers, which arise from the intrahepatic or extrahepatic bile ducts and the gallbladder, generally have a poor prognosis and are rising in incidence worldwide. The standard-of-care treatment for advanced biliary tract cancer is chemotherapy with gemcitabine and cisplatin. Because most biliary tract cancers have an immune-suppressed microenvironment, immune checkpoint inhibitor monotherapy is associated with a low objective response rate. We aimed to assess whether adding the immune checkpoint inhibitor pembrolizumab to gemcitabine and cisplatin would improve outcomes compared with gemcitabine and cisplatin alone in patients with advanced biliary tract cancer.

METHODS

KEYNOTE-966 was a randomised, double-blind, placebo-controlled, phase 3 trial done at 175 medical centres globally. Eligible participants were aged 18 years or older; had previously untreated, unresectable, locally advanced or metastatic biliary tract cancer; had disease measurable per Response Evaluation Criteria in Solid Tumours version 1.1; and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible participants were randomly assigned (1:1) to pembrolizumab 200 mg or placebo, both administered intravenously every 3 weeks (maximum 35 cycles), in combination with gemcitabine (1000 mg/m2 intravenously on days 1 and 8 every 3 weeks; no maximum duration) and cisplatin (25 mg/m2 intravenously on days 1 and 8 every 3 weeks; maximum 8 cycles). Randomisation was done using a central interactive voice-response system and stratified by geographical region, disease stage, and site of origin in block sizes of four. The primary endpoint of overall survival was evaluated in the intention-to-treat population. The secondary endpoint of safety was evaluated in the as-treated population. This study is registered at ClinicalTrials.gov, NCT04003636.

FINDINGS

Between Oct 4, 2019, and June 8, 2021, 1564 patients were screened for eligibility, 1069 of whom were randomly assigned to pembrolizumab plus gemcitabine and cisplatin (pembrolizumab group; n=533) or placebo plus gemcitabine and cisplatin (placebo group; n=536). Median study follow-up at final analysis was 25·6 months (IQR 21·7-30·4). Median overall survival was 12·7 months (95% CI 11·5-13·6) in the pembrolizumab group versus 10·9 months (9·9-11·6) in the placebo group (hazard ratio 0·83 [95% CI 0·72-0·95]; one-sided p=0·0034 [significance threshold, p=0·0200]). In the as-treated population, the maximum adverse event grade was 3 to 4 in 420 (79%) of 529 participants in the pembrolizumab group and 400 (75%) of 534 in the placebo group; 369 (70%) participants in the pembrolizumab group and 367 (69%) in the placebo group had treatment-related adverse events with a maximum grade of 3 to 4. 31 (6%) participants in the pembrolizumab group and 49 (9%) in the placebo group died due to adverse events, including eight (2%) in the pembrolizumab group and three (1%) in the placebo group who died due to treatment-related adverse events.

INTERPRETATION

Based on a statistically significant, clinically meaningful improvement in overall survival compared with gemcitabine and cisplatin without any new safety signals, pembrolizumab plus gemcitabine and cisplatin could be a new treatment option for patients with previously untreated metastatic or unresectable biliary tract cancer.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

Integration analysis of miRNA-mRNA expression exploring their potential roles in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second common primary hepatic malignancy tumor. In this study, an integrative analysis of differentially expressed genes (DEGs) and miRNAs from the ICC onset and adjacent normal tissues were performed to explore the regulatory roles of miRNA-mRNA interaction. A total of 1018 DEGs and 39 miRNAs were likely involved in ICC pathogenesis, suggesting the changes in cell metabolism in ICC development. The built network indicated that 30 DEGs were regulated by 16 differentially expressed miRNA. The screened DEGs and miRNA together were probably considered the biomarkers of ICC, and their important roles in ICC pathogenesis remain to be elucidated. This study could provide a good basis to uncover the regulatory mechanism of miRNA and mRNAs in ICC pathogenesis.

Tertiary lymphoid structures predict the prognosis and immunotherapy response of cholangiocarcinoma

Introduction

Cholangiocarcinoma (CCA) is a malignant tumor of the biliary epithelium with a poor prognosis. The lack of biomarkers to predict therapeutic response and prognosis is one of the major challenges for CCA treatment. Tertiary lymphoid structures (TLS) provide a local and pivotal microenvironment for tumor immune responses. The prognostic value and clinical relevance of TLS in CCA remain unclear. We aimed to explore the characteristics and clinical significance of TLS in CCA.

Methods

We investigated the prognostic value and clinical relevance of TLS in CCA using a surgery cohort containing 471 CCA patients (cohort 1) and an immunotherapy cohort containing 100 CCA patients (cohort 2). Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were used to evaluate the maturity of TLS. Multiplex IHC (mIHC) was employed to characterize the composition of TLS.

Results

Different maturity of TLS were observed in CCA tissue sections. Strong staining of the four-gene signature including PAX5, TCL1A, TNFRSF13C, and CD79A were found in TLS regions. A high density of intra-tumoral TLS (T-score high) were significantly correlated with longer overall survival (OS) both in CCA cohort 1 (p = 0.002) and cohort 2 (p = 0.01), whereas a high density of peri-tumoral TLS (P-score high) were associated with shorter OS in these two cohorts (p = 0.003 and p = 0.03, respectively).

Conclusion

The established four-gene signature efficiently identified the TLS in CCA tissues. The abundance and spatial distribution of TLS were significantly correlated with the prognosis and immune checkpoint inhibitors (ICIs) immunotherapy response of CCA patients. The presence of intra-tumoral TLS are positive prognostic factors for CCA, which provide a theoretical basis for the future diagnosis and treatment of CCA.

Moving beyond single-agent checkpoint inhibition in biliary tract cancers: what is the next frontier?

Background: Immunotherapy has been shown to improve outcomes for patients with cancer. Biliary tract cancers are a group of lethal diseases, and immunotherapy is an exciting new strategy to treat patients in advanced stages. Role of immunotherapy in biliary cancers: Durvalumab, an anti-PD-L1 antibody, is a new immunotherapy option for patients with advanced biliary cancers. In a randomized phase III trial, the combination of durvalumab and chemotherapy improved disease outcomes, including overall survival, in patients with advanced biliary cancers regardless of PD-L1 expression. Future perspective: Promising new combinations with new and potent antibodies or antiangiogenics are under development. Combinations with new immunotherapy agents targeting CTLA-4 or OX40 can enhance T-cell activation and improve outcomes compared with single anti-PD-1/PD-L1 agents. Furthermore, ctDNA is being used as an alternative to tissue genomic analysis and can be used to identify actionable targets. In this review, we will discuss the most important studies involving immunotherapy in biliary cancers as well as future perspectives in the field.

Non-Inflamed Tumor Microenvironment and Methylation/Downregulation of Antigen-Presenting Machineries in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a refractory cancer; a majority of CCAs represents a non-inflamed tumor phenotype that should be resistant to treatment, including immune checkpoint inhibitors (ICIs). In this study, we aimed to understand the molecular characteristics associated with non-inflamed CCAs. The genetic/epigenetic status of 36 CCAs was obtained from the Cancer Genome Atlas (PanCancerAtlas). CCAs were classified based on immune class using hierarchical clustering analysis of gene expressions related to tumor-infiltrating lymphocytes. The associations between immune class and genetic/epigenetic events were analyzed. We found that the tumors with alterations in FGFR2 and IDH1/2 had a "non-inflamed" tumor phenotype. A significant association was observed between the non-inflamed group and the downregulation of genes involved in antigen presentation (p = 0.0015). The expression of antigen-presenting machineries was inversely correlated with their DNA methylation levels, where 33.3% of tumors had an upregulation/low-methylation pattern, and 66.7% of tumors had a downregulation/high-methylation pattern. All tumors in the "inflamed" group exhibited an upregulation/low-methylation pattern. In contrast, 24 of 30 tumors in the non-inflamed group represent the downregulation/high-methylation pattern (p = 0.0005). Methylation with downregulation of antigen-presenting machineries is associated with the "non-inflamed" tumor phenotype of CCAs. This evidence provides important insights for developing new strategies for treating CCA.

Targeting Angiogenesis in the Era of Biliary Tract Cancer Immunotherapy: Biological Rationale, Clinical Implications, and Future Research Avenues

Although biliary tract cancers are traditionally considered rare in Western countries, their incidence and mortality rates are rising worldwide. A better knowledge of the genomic landscape of these tumor types has broadened the number of molecular targeted therapies, including angiogenesis inhibitors. The role of immune checkpoint inhibitors (ICIs) could potentially change the first-line therapeutic approach, but monotherapy with ICIs has shown disappointing results in CCA. Several clinical trials are evaluating combination strategies that include immunotherapy together with other anticancer agents with a synergistic activity. The tumor microenvironment (TME) composition plays a pivotal role in the prognosis of BTC patients. The accumulation of immunosuppressive cell types, such as tumor-associated macrophages (TAMs) and regulatory T-cells, together with the poor infiltration of cytotoxic CD8+ T-cells, is known to predispose to a poor prognosis owing to the establishment of resistance mechanisms. Likewise, angiogenesis is recognized as a major player in modulating the TME in an immunosuppressive manner. This is the mechanistic rationale for combination treatment schemes blocking both immunity and angiogenesis. In this scenario, this review aims to provide an overview of the most recent completed or ongoing clinical trials combining immunotherapy and angiogenesis inhibitors with/without a chemotherapy backbone.

Cancer-Associated Fibroblasts and Extracellular Matrix: Therapeutical Strategies for Modulating the Cholangiocarcinoma Microenvironment

During the last decade, immunotherapy has radically changed perspectives on anti-tumor treatments. However, solid tumor treatment by immunotherapy has not met expectations. Indeed, poor clinical response to treatment has highlighted the need to understand and avoid immunotherapy resistance. Cholangiocarcinoma (CCA) is the second cause of hepatic cancer-related deaths because of drug inefficacy and chemo-resistance in a majority of patients. Thus, intense research is ongoing to better understand the mechanisms involved in the chemo-resistance processes. The tumor microenvironment (TME) may be involved in tumor therapy resistance by limiting drug access. Indeed, cells such as cancer-associated fibroblasts (CAFs) alter TME by producing in excess an aberrant extracellular matrix (ECM). Interestingly, CAFs are the dominant stromal component in CCA that secrete large amounts of stiff ECM. Stiff ECM could contribute to immune exclusion by limiting anti-tumor T-cells drop-in. Herein, we summarize features, functions, and interactions among CAFs, tumor-associated ECM, and immune cells in TME. Moreover, we discuss the strategies targeting CAFs and the remodeling of the ECM to improve immunotherapy and drug therapies.

Novel microenvironment-based classification of intrahepatic cholangiocarcinoma with therapeutic implications

OBJECTIVE

The diversity of the tumour microenvironment (TME) of intrahepatic cholangiocarcinoma (iCCA) has not been comprehensively assessed. We aimed to generate a novel molecular iCCA classifier that incorporates elements of the stroma, tumour and immune microenvironment ('STIM' classification).

DESIGN

We applied virtual deconvolution to transcriptomic data from ~900 iCCAs, enabling us to devise a novel classification by selecting for the most relevant TME components. Murine models were generated through hydrodynamic tail vein injection and compared with the human disease.

RESULTS

iCCA is composed of five robust STIM classes encompassing both inflamed (35%) and non-inflamed profiles (65%). The inflamed classes, named immune classical (~10%) and inflammatory stroma (~25%), differ in oncogenic pathways and extent of desmoplasia, with the inflammatory stroma showing T cell exhaustion, abundant stroma and KRAS mutations (p<0.001). Analysis of cell-cell interactions highlights cancer-associated fibroblast subtypes as potential mediators of immune evasion. Among the non-inflamed classes, the desert-like class (~20%) harbours the lowest immune infiltration with abundant regulatory T cells (p<0.001), whereas the hepatic stem-like class (~35%) is enriched in 'M2-like' macrophages, mutations in IDH1/2 and BAP1, and FGFR2 fusions. The remaining class (tumour classical: ~10%) is defined by cell cycle pathways and poor prognosis. Comparative analysis unveils high similarity between a KRAS/p19 murine model and the inflammatory stroma class (p=0.02). The KRAS-SOS inhibitor, BI3406, sensitises a KRAS-mutant iCCA murine model to anti-PD1 therapy.

CONCLUSIONS

We describe a comprehensive TME-based stratification of iCCA. Cross-species analysis establishes murine models that align closely to human iCCA for the preclinical testing of combination strategies.