Distinct clinical and prognostic implication of IDH1/2 mutation and other most frequent mutations in large duct and small duct subtypes of intrahepatic cholangiocarcinoma

Genomic and transcriptomic signatures of sequential carcinogenesis from papillary neoplasm to biliary tract cancer

BACKGROUND & AIMS

Papillary neoplasms of the biliary tree, including intraductal papillary neoplasms (IPN) and intracholecystic papillary neoplasms (ICPN), are recognized as precancerous lesions. However, the genetic characteristics underlying sequential carcinogenesis remain unclear.

METHODS

Whole-exome sequencing was performed on 166 neoplasms (33 intrahepatic IPNs, 44 extrahepatic IPNs, and 89 ICPNs), and 41 associated carcinomas. Nine available cases were also subjected to spatial transcriptomic analysis.

RESULTS

Mutations in the MAPK (48%), genomic integrity maintenance (42%), and Wnt/β-catenin (33%) pathways were prevalent in intrahepatic IPNs, extrahepatic IPNs, and ICPNs, respectively. KRAS mutations were enriched in intrahepatic IPN (42%, P<0.001), whereas SMAD4 mutations were enriched in extrahepatic IPN (21%, P=0.005). ICPNs frequently exhibit CTNNB1 mutations, particularly in low-grade lesions. Mutational signature analysis revealed that SBS1 and SBS5 signatures were homogeneously enriched in intrahepatic IPN, in contrast to the heterogeneous distribution of SBS1, SBS2, SBS5, SBS13, SBS7b, and SBS23 in extrahepatic IPN and ICPN. Copy number aberrations gradually increased from low- to high-grade intraepithelial neoplasia and eventually to carcinoma. Phylogenetic analysis revealed that 89% of carcinomas were derived from IPN/ICPN through sequential carcinogenesis, with the majority sharing driver mutations between IPN/ICPN and carcinoma. Furthermore, multifocal, independent carcinogenesis events were observed in IPNs/ICPNs, resulting in mutationally distinct carcinoma lesions. Carcinogenesis of IPN/ICPN occurs in multiple subclones through mutational accumulation and transcriptomic alterations that affect vascular development, cell morphogenesis, extracellular matrix organization, and growth factor response.

CONCLUSIONS

With the largest IPN/ICPN cohort reported to date, our study provides a genome- and spatial transcriptome-level portrait of sequential carcinogenesis and differences in the anatomical location of biliary papillary neoplasms.

IMPACT AND IMPLICATIONS

Biliary tract cancer is a fatal malignancy. However, its genome-level sequential carcinogenesis from intraepithelial neoplasia to carcinoma has not yet been evaluated in a sufficiently large cohort. Papillary lesions of the bile duct and gallbladder are collectively termed intraductal papillary neoplasms (IPN) of the bile duct and intracholecystic papillary neoplasms (ICPN), respectively. They are primarily diagnosed based on histopathological studies. This study provides a comprehensive mutational and spatial transcriptomic landscape of papillary neoplasms of the bile duct and gallbladder. The results of this study offer insights into the mechanism of sequential carcinogenesis in papillary biliary tract tumors, pathology-genomics correlation, and potential therapeutic targets.

Surgical interpretation of the WHO subclassification of intrahepatic cholangiocarcinoma: a narrative review

Intrahepatic cholangiocarcinoma (iCCA) has been subclassified by its gross morphology into the mass-forming (MF), periductal-infiltrating (PI), and intraductal growth (IG) types and their combinations. This classification correlates well with clinical features; for example, MF-iCCA has less lymph-node metastasis and a better prognosis than PI-iCCA. According to the recently accumulated evidence from histological investigations, the WHO classification endorsed a subclassification scheme in which iCCA cases are classified into small- and large-duct types. Small-duct iCCA is considered to originate from septal or smaller bile ducts and is characterized by less frequent lymph-node metastasis, a favorable prognosis, and an MF appearance. Large-duct iCCA arises around the second branch of the biliary tree and has more aggressive biology and distinct genetic abnormalities. According to the practice guidelines for iCCA from the Liver Cancer Study Group of Japan and the National Comprehensive Cancer Network, upfront surgery is recommended for iCCA without distant metastasis regardless of the morphological subtype, based on clinical experience. In consideration of the biological heterogeneity of iCCA, the treatment strategy for iCCA needs to be reconsidered based on the WHO subtypes.

Classification of intrahepatic cholangiocarcinoma

Cholangiocarcinoma is a heterogenous malignancy with various classifications based on location, morphological features, histological features, and actionable genetic mutations. Intrahepatic cholangiocarcinoma (ICC), which arises in and proximal to second order bile ducts, is the second most common primary liver malignancy after hepatocellular carcinoma. In this review, we will discuss ICC risk factors, precursor lesions, various growth, anatomic, morphologic, and histologic classifications, rare variants, and differential diagnoses.

Morphomolecular Pathology and Genomic Insights into the Cells of Origin of Cholangiocarcinoma and Combined Hepatocellular-Cholangiocarcinoma

Cholangiocarcinomas are a highly heterogeneous group of malignancies that, despite recent progress in the understanding of their molecular pathogenesis and clinical management, continue to pose a major challenge to public health. The traditional view posits that cholangiocarcinomas derive from the neoplastic transformation of cholangiocytes lining the biliary tree. However, increasing genetic and experimental evidence has recently pointed to a more complex, and nuanced, scenario for the potential cell of origin of cholangiocarcinomas. Hepatocytes as well as hepatic stem/progenitor cells are being considered as additional potential sources, depending on microenvironmental contexts, including liver injury. The hypothesis of potentially diverse cells of origin for cholangiocarcinoma, albeit controversial, is certainly not surprising given the plasticity of the cells populating the liver as well as the existence of liver cancer subtypes with mixed histologic and molecular features. This review carefully examines the current pathologic, genomic, and experimental evidence supporting the existence of multiple cells of origin of liver and biliary tract cancers, with particular focus on cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma.

Targeting Isocitrate Dehydrogenase (IDH) in Solid Tumors: Current Evidence and Future Perspectives

The isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) enzymes are involved in key metabolic processes in human cells, regulating differentiation, proliferation, and oxidative damage response. IDH mutations have been associated with tumor development and progression in various solid tumors such as glioma, cholangiocarcinoma, chondrosarcoma, and other tumor types and have become crucial markers in molecular classification and prognostic assessment. The intratumoral and serum levels of D-2-hydroxyglutarate (D-2-HG) could serve as diagnostic biomarkers for identifying IDH mutant (IDHmut) tumors. As a result, an increasing number of clinical trials are evaluating targeted treatments for IDH1/IDH2 mutations. Recent studies have shown that the focus of these new therapeutic strategies is not only the neomorphic activity of the IDHmut enzymes but also the epigenetic shift induced by IDH mutations and the potential role of combination treatments. Here, we provide an overview of the current knowledge about IDH mutations in solid tumors, with a particular focus on available IDH-targeted treatments and emerging results from clinical trials aiming to explore IDHmut tumor-specific features and to identify the clinical benefit of IDH-targeted therapies and their combination strategies. An insight into future perspectives and the emerging roles of circulating biomarkers and radiomic features is also included.

Intrahepatic cholangiocarcinoma: Evolving strategies in management and treatment

Intrahepatic cholangiocarcinoma is the second most frequent primary liver cancer after hepatocellular carcinoma. According to International Classification of Diseases-11 (ICD-11), intrahepatic cholangiocarcinoma is identified by a specific diagnostic code, different with respect to perihilar-CCA or distal-CCA. Intrahepatic cholangiocarcinoma originates from intrahepatic small or large bile ducts including the second-order bile ducts and has a silent presentation that combined with the highly aggressive nature and refractoriness to chemotherapy contributes to the alarming increasing incidence and mortality. Indeed, at the moment of the diagnosis, less than 40% of intrahepatic cholangiocarcinoma are suitable of curative surgical therapy, that is so far the only effective treatment. The main goals of clinicians and researchers are to make an early diagnosis, and to carry out molecular characterization to provide the patient with personalized treatment. Unfortunately, these goals are not easily achievable because of the heterogeneity of this tumor from anatomical, molecular, biological, and clinical perspectives. However, recent progress has been made in molecular characterization, surgical treatment, and management of intrahepatic cholangiocarcinoma and, this article deals with these advances.

Expert Consensus on Pathological Diagnosis of Intrahepatic Cholangiocarcinoma (2022 version)

Intrahepatic cholangiocarcinoma (iCCA) can originate from the large bile duct group (segment bile ducts and area bile ducts), small bile duct group (septal bile ducts and interlobular bile ducts), and terminal bile duct group (bile ductules and canals of Hering) of the intrahepatic biliary tree, which can be histopathological corresponding to large duct type iCCA, small duct type iCCA and iCCA with ductal plate malformation pattern, and cholangiolocarcinoma, respectively. The challenge in pathological diagnosis of above subtypes of iCCA falls in the distinction of cellular morphologies, tissue structures, growth patterns, invasive behaviors, immunophenotypes, molecular mutations, and surgical prognoses. For these reasons, this expert consensus provides nine recommendations as a reference for standardizing and refining the diagnosis of pathological subtypes of iCCA, mainly based on the 5th edition of the World Health Organization Classification of Tumours of the Digestive System.

EASL-ILCA Clinical Practice Guidelines on the management of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) develops inside the liver, between bile ductules and the second-order bile ducts. It is the second most frequent primary liver cancer after hepatocellular carcinoma, and its global incidence is increasing. It is associated with an alarming mortality rate owing to its silent presentation (often leading to late diagnosis), highly aggressive nature and resistance to treatment. Early diagnosis, molecular characterisation, accurate staging and personalised multidisciplinary treatments represent current challenges for researchers and physicians. Unfortunately, these challenges are beset by the high heterogeneity of iCCA at the clinical, genomic, epigenetic and molecular levels, very often precluding successful management. Nonetheless, in the last few years, progress has been made in molecular characterisation, surgical management, and targeted therapy. Recent advances together with the awareness that iCCA represents a distinct entity amongst the CCA family, led the ILCA and EASL governing boards to commission international experts to draft dedicated evidence-based guidelines for physicians involved in the diagnostic, prognostic, and therapeutic management of iCCA.

JARID2 and EZH2, The Eminent Epigenetic Drivers In Human Cancer

Cancer has become a prominent cause of death, accounting for approximately 10 million death worldwide as per the World Health Organization reports 2020. Epigenetics deal with the alterations of heritable phenotypes, except for DNA alterations. Currently, we are trying to comprehend the role of utmost significant epigenetic genes involved in the burgeoning of human cancer. A sundry of studies reported the Enhancer of Zeste Homologue2 (EZH2) as a prime catalytic subunit of Polycomb Repressive Complex2, which is involved in several pivotal activities, including embryogenesis. In addition, EZH2 has detrimental effects leading to the onset and metastasis of several cancers. Jumonji AT Rich Interacting Domain2 (JARID2), an undebated crucial nuclear factor, has strong coordination with the PRC2 family. In this review, we discuss various epigenetic entities, primarily focusing on the possible role and mechanism of EZH2 and the significant contribution of JARID2 in human cancers.

Are FGFR and IDH1-2 alterations a positive prognostic factor in intrahepatic cholangiocarcinoma? An unresolved issue

Despite representing some of the most common and investigated molecular changes in intrahepatic cholangiocarcinoma (iCCA), the prognostic role of FGFR and IDH1/2 alterations still remains an open question. In this review we provide a critical analysis of available literature data regarding this topic, underlining the strengths and pitfalls of each study reported. Despite the overall poor quality of current available studies, a general trend toward a better overall survival for FGFR2 rearrangements and, possibly, for FGFR2-3 alterations can be inferred. On the other hand, the positive prognostic role of IDH1/2 mutation seems much more uncertain. In this scenario, better designed clinical trials in these subsets of iCCA patients are needed in order to get definitive conclusions on this issue.

Whole-genome sequencing of 20 cholangiocarcinoma cases reveals unique profiles in patients with cirrhosis and primary sclerosing cholangitis

Background

Cholangiocarcinoma (CCA) is a molecularly heterogenous disease that is often fatal. Whole genome sequencing (WGS) can provide additional knowledge of mutational spectra compared with panel sequencing. We describe the molecular landscape of CCA using whole-genome sequencing and compare the mutational landscape between short-term and long-term survivors.

Methods

We explored molecular differences between short-term and long-term survivors by performing WGS on 20 patient samples from our biliary tract cancer database. Short-term survivors were enriched for cases with underlying primary sclerosing cholangitis (PSC) and patients with cirrhosis. All samples underwent tumour epithelial enrichment using laser capture microdissection (LCM).

Results

Dominant single base substitution (SBS) signatures across the cohort included SBS1 and SBS5, with the latter more prevalent in long-term survivors. SBS17 was evident in 3 cases, all of whom had underlying ulcerative colitis (UC) with PSC. Additional rare signatures included SBS3 in a patient treated for prior mantle cell lymphoma and SBS26/SBS6 in a patient with a tumor mutational burden of 33 mutations/Mb and a pathogenic MLH1 germline mutation. Somatic TP53 inactivating mutations were present in 8/10 (80%) short-term survivors and in none of the long-term survivors. Additional mutations occurred in KRAS, SMAD4, CDKN2A, and chromatin remodelling genes. The long-term survivor group harboured predicted fusions in FGFR (n=2) and pathogenic mutations in BRAF and IDH1 (n=2).

Conclusions

TP53 alterations are associated with poor outcomes in patients with CCA. Patients with underlying inflammatory/autoimmune conditions may be enriched for unique tumour mutational signatures.

Optimizing Circulating Tumour DNA Use in the Perioperative Setting for Intrahepatic Cholangiocarcinoma: Diagnosis, Screening, Minimal Residual Disease Detection and Treatment Response Monitoring

In this review, we present the current evidence and future perspectives on the use of circulating tumour DNA (ctDNA) in the diagnosis, management and understanding the prognosis of patients with intrahepatic cholangiocarcinoma (iCCA) undergoing surgery. Liquid biopsies or ctDNA maybe utilized to: (1) determine the molecular profile of the tumour and therefore guide the selection of molecular targeted therapy in the neoadjuvant setting, (2) form a surveillance tool for the detection of minimal residual disease or cancer recurrence after surgery, and (3) diagnose and screen for early iCCA detection in high-risk populations. The potential for ctDNA can be tumour-informed or -uninformed depending on the goals of its use. Future studies will require ctDNA extraction technique validations, with standardizations of both the platforms and the timing of ctDNA collections.

The clinical value of identifying genetic abnormalities that can be targeted in cholangiocarcinomas

INTRODUCTION

Cholangiocarcinomas (CCAs) are a heterogenous group of epithelial malignancies originating at any level of the biliary tree and are subdivided according to their location into intrahepatic (iCCA) and extrahepatic (eCCA).

AREAS COVERED

This review provides an updated analysis of studies of genetic characterization of CCA at the level of gene mutation profiling, copy number alterations and gene expression, with definition of molecular subgroups and identification of some molecular biomarkers and therapeutic targets.

EXPERT OPINION

With the development of genetic sequencing, several driver mutations have been identified and targeted as novel therapeutic approaches, including FGFR2, IDH1, BRAF, NTRK, HER2, ROS, and RET. Furthermore, identification of the cellular and molecular structure of the tumor microenvironment has contributed to the development of novel therapies, such as tumor immunotherapy. Combination therapies of chemotherapy plus targeted molecules or immunotherapy are under evaluation and offer the unique opportunity to improve the outcomes of CCA patients with advanced disease.

Clinical Outcomes After Progression on First-Line Therapies in IDH1 Mutated Versus Wild-Type Intrahepatic Cholangiocarcinoma Patients

BACKGROUND

Isocitrate dehydrogenase-1 (IDH1) mutations occur in a significant proportion of intrahepatic cholangiocarcinomas (iCCAs). No data are available regarding the prognostic impact of IDH1 mutations in advanced iCCA patients after progression on first-line therapies.

OBJECTIVE

We investigated the role of IDH1 mutation in advanced iCCA after progression on first-line therapies.

PATIENTS AND METHODS

After progression on first-line therapies for advanced iCCA, consecutive patients were retrospectively collected. The IDH1 status was tested at baseline. This analysis aimed to examine the association between the presence of IDH1 missense mutations and survival outcomes in patients with advanced iCCA treated with a second-line therapy.

RESULTS

The analysis included 119 patients; 56/119 (47%) were IDH1 mutated (IDH1m) and 63/119 (53%) were IDH1 wild type (IDH1 WT). At univariate analysis for overall survival (OS), the presence of IDH1 mutation was associated with a worse median OS (mOS; 8.2 vs. 14.1 months; hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.2-3.0, p = 0.0047). Patients harboring IDH1 mutations showed a worse objective response rate (ORR) compared with patients without IDH1 mutation, whereas no significant differences in disease control rate (DCR) were found. Multivariate analysis confirmed IDH1 mutations as an independent negative prognostic factor for OS (HR 1.7, 95% CI 1.1-2.7, p = 0.0256). By evaluating only patients receiving FOLFOX as second-line therapy, no statistically significant differences were found in terms of both OS and PFS between IDH1m and IDH1 WT patients. In this subset of patients, those harboring an IDH1 mutation showed a worse ORR and DCR compared with those without. Finally, at univariate analysis for OS from third-line treatment, the presence of an IDH1 mutation was associated with a trend toward a worse mOS (6.0 vs. 11.9 months; HR 1.6, 95% CI 0.8-3.2, p = 0.25).

CONCLUSION

The present analysis constitutes the first evidence of a negative prognostic impact of IDH1 mutations in a cohort of patients treated after progression on first-line therapies in contrast to IDH1 inhibitors.

Implication of Ferroptosis in Cholangiocarcinoma: A Potential Future Target?

Cholangiocarcinoma (CCA), the second most common liver neoplasm, has a poor overall 5-year survival rate of less than 10%. A deeper understanding of the molecular pathogenesis contributing to CCA progression is essential for developing better therapeutic approaches to manage this disease. Ferroptosis, an oxidative iron-dependent form of regulated cell death, has been reported to be involved in tumorigenesis and progression. In particular, ferroptosis and inflammation, which are common issues in cholangiocarcinogenesis and CCA development, might be in concert with disease progression. Notably, the key feature of cancer cells is "iron addiction", which is crucial for the high metabolic demand in carcinogenesis and cancer progression. Additionally, iron metabolism is of great importance in ferroptosis. Moreover, that cancer cells are vulnerable to ferroptosis might be a possible mechanism of CCA development. Although the underlying mechanism of how ferroptosis is implicated in CCA development requires further investigation, developing a new strategy combined with a pro-ferroptotic treatment would be an exciting CCA treatment approach in the future.

Pemigatinib in Intrahepatic Cholangiocarcinoma: A Work in Progress

Cholangiocarcinoma (CCA) is the second most frequent primary liver cancer, following hepatocellular carcinoma (HCC). Progress in the molecular understanding of CCA has led to the development of several agents, including FGFR inhibitors, such as pemigatinib, whose approval has marked a new era in this hepatobiliary malignancy. However, a number of questions remain unanswered, including the development of secondary resistance and the role of combination therapies, including FGFR inhibitors. Herein, we specifically focus on the current challenges and future research directions of pemigatinib use in CCA patients.

Clinical relevance of biomarkers in cholangiocarcinoma: critical revision and future directions

Cholangiocarcinoma (CCA) is a malignant tumour arising from the biliary system. In Europe, this tumour frequently presents as a sporadic cancer in patients without defined risk factors and is usually diagnosed at advanced stages with a consequent poor prognosis. Therefore, the identification of biomarkers represents an utmost need for patients with CCA. Numerous studies proposed a wide spectrum of biomarkers at tissue and molecular levels. With the present paper, a multidisciplinary group of experts within the European Network for the Study of Cholangiocarcinoma discusses the clinical role of tissue biomarkers and provides a selection based on their current relevance and potential applications in the framework of CCA. Recent advances are proposed by dividing biomarkers based on their potential role in diagnosis, prognosis and therapy response. Limitations of current biomarkers are also identified, together with specific promising areas (ie, artificial intelligence, patient-derived organoids, targeted therapy) where research should be focused to develop future biomarkers.

Molecular Profile and Prognostic Value of BAP1 Mutations in Intrahepatic Cholangiocarcinoma: A Genomic Database Analysis

Background. Recent years have witnessed the advent of molecular profiling for intrahepatic cholangiocarcinoma (iCCA), and new techniques have led to the identification of several molecular alterations. Precision oncology approaches have been widely evaluated and are currently under assessment, as shown by the recent development of a wide range of agents targeting Fibroblast Growth Factor Receptor (FGFR) 2, Isocitrate Dehydrogenase 1 (IDH-1), and BRAF. However, several knowledge gaps persist in the understanding of the genomic landscape of this hepatobiliary malignancy. Methods. In the current study, we aimed to comprehensively analyze clinicopathological features of BAP1-mutated iCCA patients in public datasets to increase the current knowledge on the molecular and biological profile of iCCA. Results. The current database study, including 772 iCCAs, identified BAP1 mutations in 120 cases (15.7%). According to our analysis, no differences in terms of overall survival and relapse-free survival were observed between BAP1-mutated and BAP1 wild-type patients receiving radical surgery. In addition, IDH1, PBRM1, and ARID1A mutations were the most commonly co-altered genes in BAP1-mutated iCCAs. Conclusions. The genomic characterization of iCCA is destined to become increasingly important, and more efforts aimed to implement iCCA genomics analysis are warranted.

Triple therapy in biliary tract cancers: GemOX plus immune checkpoint inhibitor in combination with lenvatinib or NGS-guided targeted therapy

PURPOSE

The combination of gemcitabine-based chemotherapy and immune checkpoint inhibitors has a good efficacy in advanced biliary tract cancer (BTC). The multi-target TKI lenvatinib and NGS-guided targeted therapy are also promising in BTC treatment. This study aimed to explore the performance of GemOX plus sintilimab and TKI (either lenvatinib or by NGS-guided targeted therapy) for local advanced or metastatic BTCs.

METHODS

This prospective single-arm study included patients with local advanced or metastatic BTCs and applied intravenous infusion of standard GemOX plus sintilimab and lenvatinib (no targetable gene alterations) or targeted therapy based on NGS (olaparib for BRCA1/2 mutation, dasatinib for IDH1/2 mutation, afatinib for EGFR amplification, lenvatinib for PDGFR and KIT mutation, and lenvatinib for FGFR/KIT mutation).

RESULTS

From November 2020 to December 2021, 22 patients BTCs (6 GBC, 14 iCCA, 1 pCCA and 1 dCCA cases) were enrolled, with an average age of 58.4 years. Partial response (PR) was achieved in 10 cases, stable disease (SD) in 9 cases and progression disease (PD) in 3 cases (13.6%). The objective response rate (ORR) was 45.5%, and the disease control rate (DCR) was 86.4%. During the treatment, the incidence of adverse reactions was 81.8%, and the incidence of grade 3/4 adverse events was 9.09%. For 14 patients with NGS, 5 patients were treated by targeted therapy and there were 1 SD and 4 PR cases. For four patients with positive PD-L1 expression, the ORR was 100%. While among the three patients with super-progression markers such as RET, MDM2 and FGF14/STK24, there were two SD and one PD cases.

CONCLUSION

In patients with advanced BTCs, the combination of GemOX plus sintilimab and lenvatinib or NGS-guided targeted therapy showed promising ORR and DCR, especially for the patients with positive PD-L1 expression and targetable gene alterations.

Morphomolecular Classification Update on Hepatocellular Adenoma, Hepatocellular Carcinoma, and Intrahepatic Cholangiocarcinoma

Hepatocellular adenomas (HCAs), hepatocellular carcinomas (HCCs), and intrahepatic cholangiocarcinomas (iCCAs) are a highly heterogeneous group of liver tumors with diverse pathomolecular features and prognoses. High-throughput gene sequencing techniques have allowed discovery of distinct genetic and molecular underpinnings of these tumors and identified distinct subtypes that demonstrate varied clinicobiologic behaviors, imaging findings, and complications. The combination of histopathologic findings and molecular profiling form the basis for the morphomolecular classification of liver tumors. Distinct HCA subtypes with characteristic imaging findings and complications include HNF1A-inactivated, inflammatory, β-catenin-activated, β-catenin-activated inflammatory, and sonic hedgehog HCAs. HCCs can be grouped into proliferative and nonproliferative subtypes. Proliferative HCCs include macrotrabecular-massive, TP53-mutated, scirrhous, clear cell, fibrolamellar, and sarcomatoid HCCs and combined HCC-cholangiocarcinoma. Steatohepatitic and β-catenin-mutated HCCs constitute the nonproliferative subtypes. iCCAs are classified as small-duct and large-duct types on the basis of the level of bile duct involvement, with significant differences in pathogenesis, molecular signatures, imaging findings, and biologic behaviors. Cross-sectional imaging modalities, including multiphase CT and multiparametric MRI, play an essential role in diagnosis, staging, treatment response assessment, and surveillance. Select imaging phenotypes can be correlated with genetic abnormalities, and identification of surrogate imaging markers may help avoid genetic testing. Improved understanding of morphomolecular features of liver tumors has opened new areas of research in the targeted therapeutics and management guidelines. The purpose of this article is to review imaging findings of select morphomolecular subtypes of HCAs, HCCs, and iCCAs and discuss therapeutic and prognostic implications. Online supplemental material is available for this article. ^©RSNA, 2022.

Biology of IDH mutant cholangiocarcinoma

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are the most frequently mutated metabolic genes across human cancers. These hotspot gain-of-function mutations cause the IDH enzyme to aberrantly generate high levels of the oncometabolite, R-2-hydroxyglutarate, which competitively inhibits enzymes that regulate epigenetics, DNA repair, metabolism, and other processes. Among epithelial malignancies, IDH mutations are particularly common in intrahepatic cholangiocarcinoma (iCCA). Importantly, pharmacological inhibition of mutant IDH (mIDH) 1 delays progression of mIDH1 iCCA, indicating a role for this oncogene in tumor maintenance. However, not all patients receive clinical benefit, and those who do typically show stable disease rather than significant tumor regressions. The elucidation of the oncogenic functions of mIDH is needed to inform strategies that can more effectively harness mIDH as a therapeutic target. This review will discuss the biology of mIDH iCCA, including roles of mIDH in blocking cell differentiation programs and suppressing antitumor immunity, and the potential relevance of these effects to mIDH1-targeted therapy. We also cover opportunities for synthetic lethal therapeutic interactions that harness the altered cell state provoked by mIDH1 rather than inhibiting the mutant enzyme. Finally, we highlight key outstanding questions in the biology of this fascinating and incompletely understood oncogene.

Up-to-Date Pathologic Classification and Molecular Characteristics of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive primary liver malignancy with an increasing incidence worldwide. Recently, histopathologic classification of small duct type and large duct type iCCA has been introduced. Both these types of tumors exhibit differences in clinicopathological features, mutational profiles, and prognosis. Small duct type iCCA is composed of non-mucin-producing cuboidal cells, whereas large duct type iCCA is composed of mucin-producing columnar cells, reflecting different cells of origin. Large duct type iCCA shows more invasive growth and poorer prognosis than small duct type iCCA. The background liver of small duct type iCCA often shows chronic liver disease related to hepatitis B or C viral infection, or alcoholic or non-alcoholic fatty liver disease/steatohepatitis, in contrast to large duct type iCCA that is often related to hepatolithiasis and liver fluke infection. Cholangiolocarcinoma is a variant of small duct type iCCA composed of naïve-looking cuboidal cells forming cords or ductule-like structures, and shows better prognosis than the conventional small duct type. Fibrous tumor stroma, one of the characteristic features of iCCA, contains activated fibroblasts intermixed with innate and adaptive immune cells. The types of stroma (mature versus immature) are related to tumor behavior and prognosis. Low tumor-infiltrating lymphocyte density, KRAS alteration, and chromosomal instability are related to immune-suppressive tumor microenvironments with resistance to programmed death 1/ programmed death ligand 1 blockade. Data from recent large-scale exome analyses have revealed the heterogeneity in the molecular profiles of iCCA, showing that small duct type iCCA exhibit frequent BAP1, IDH1/2 hotspot mutations and FGFR2 fusion, in contrast to frequent mutations in KRAS, TP53, and SMAD4 observed in large duct type iCCA. Multi-omics analyses have proposed several molecular classifications of iCCA, including inflammation class and proliferation class. The inflammation class is enriched in inflammatory signaling pathways and expression of cytokines, while the proliferation class has activated oncogenic growth signaling pathways. Diverse pathologic features of iCCA and its associated multi-omics characteristics are currently under active investigation, thereby providing insights into precision therapeutics for patients with iCCA. This review provides the latest knowledge on the histopathologic classification of iCCA and its associated molecular features, ranging from tumor microenvironment to genomic and transcriptomic research.

Systemic Treatment for Metastatic Biliary Tract Cancer: State of the Art and a Glimpse to the Future

Recent years have seen some breakthroughs in the therapeutic landscape of advanced biliary tract cancer (BTC). Firstly, a better understanding of the molecular background of BTC has led to important improvements in the management of these hepatobiliary malignancies, with the advent of targeted agents representing an unprecedented paradigm shift, as witnessed by the FDA approval of pemigatinib and infigratinib for FGFR2-rearranged and ivosidenib in IDH1-mutant cholangiocarcinoma. In addition, several novel treatments are under assessment, including immune checkpoint inhibitors and combination chemotherapies. In the current review, we provide an overview of systemic treatment for metastatic BTC, summarizing recent clinical data on chemotherapy as well as the main results of targeted therapies and immunotherapy.

Isocitrate Dehydrogenase-Mutated Cholangiocarcinoma: Natural History and Clinical Outcomes

PURPOSE

Clinical-pathologic features and natural history of patients with isocitrate dehydrogenase (IDH)-mutant intrahepatic cholangiocarcinoma (CCA) are not well characterized. Here, we sought to describe the natural history, clinical phenotype, and prognostic impact of advanced, IDH-mutated CCA.

METHODS

We conducted a multicentric, retrospective analysis of patients with IDH-mutated (IDH1 or IDH2) CCA between 2010 and 2020. Median overall survival (OS) and progression-free survival (PFS) analyses were performed using the Kaplan-Meier method. Chi-square test was used to analyze disease control rate (DCR) and overall response rate (ORR). Matched controls were used for comparing survival between patients with and without IDH mutations (mIDH).

RESULTS

Sixty-five patients with IDH-mutated CCA were included. All patients had intrahepatic CCA. On first-line chemotherapy, median OS and median PFS were 21.2 months and 8.3 months, respectively. Notably, median OS (32.4 v 19.5 months, P = .12) and PFS (18.0 v 8.0 months, P = .12) were not significantly affected by disease status at presentation (locally advanced v metastatic, respectively). Median OS was significantly longer in patients with mIDH (21.2 v 10.5 months; P < .01). First-line gemcitabine-containing regimens had a significantly higher DCR and ORR than non-gemcitabine-containing regimens (DCR: 75% v 33%, P = .01; ORR: 39% v 0%, P = .02). In patients receiving IDH inhibitor therapy, median PFS was 4.6 months with a DCR of 29%.

CONCLUSION

CCA with mIDH confers a unique subtype resulting in a better survival compared with that of counterparts. IDH inhibitors represent a promising therapeutic option in later lines of therapy in this subgroup.

A2M is a potential core gene in intrahepatic cholangiocarcinoma

Background

Intrahepatic cholangiocarcinoma (ICC) is a type of malignant tumor ranking the second in the incidence of primary liver cancer following hepatocellular carcinoma. Both the morbidity and mortality have been increasing in recent years. Small duct type of ICC has potential therapeutic targets. But overall, the prognosis of patients with ICC is usually very poor.

Methods

To search latent therapeutic targets for ICC, we programmatically selected the five most suitable microarray datasets. Then, we made an analysis of these microarray datasets (GSE26566, GSE31370, GSE32958, GSE45001 and GSE76311) collected from the Gene Expression Omnibus (GEO) database. The GEO2R tool was effective to find out differentially expressed genes (DEGs) between ICC and normal tissue. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were executed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) v 6.8. The Search Tool for the Retrieval of Interacting Genes (STRING) database was used to analyze protein–protein interaction of these DEGs and protein–protein interaction of these DEGs was modified by Cytoscape3.8.2. Survival analysis was performed using Gene Expression Profiling Interactive Analysis (GEPIA) online analysis tool.

Results

A total of 28 upregulated DEGs and 118 downregulated DEGs were screened out. Then twenty hub genes were selected according to the connectivity degree. The survival analysis results showed that A2M was closely related to the pathogenesis and prognosis of ICC and was a potential therapeutic target for ICC.

Conclusions

According to our study, low A2M expression in ICC compared to normal bile duct tissue was an adverse prognostic factor in ICC patients. The value of A2M in the treatment of ICC needs to be further studied.

Epigenetic upregulation of TET2 is an independent poor prognostic factor for intrahepatic cholangiocarcinoma

Mutations in IDH1/2 and the epigenetic silencing of TET2 occur in leukaemia or glioma in a mutually exclusive manner. Although intrahepatic cholangiocarcinoma (iCCA) may harbour IDH1/2 mutations, the contribution of TET2 to carcinogenesis remains unknown. In the present study, the expression and promoter methylation of TET2 were investigated in iCCA. The expression of TET2 was assessed in 52 cases of iCCA (small-duct type, n = 33; large-duct type, n = 19) by quantitative PCR, immunohistochemistry (IHC) and a sequencing-based methylation assay, and its relationships with clinicopathological features and alterations in cancer-related genes (e.g., KRAS and IDH1) were investigated. In contrast to non-neoplastic bile ducts, which were negative for TET2 on IHC, 42 cases (81%) of iCCA showed the nuclear overexpression of TET2. Based on IHC scores (area × intensity), these cases were classified as TET2-high (n = 25) and TET2-low (n = 27). The histological type, tumour size, lymph node metastasis and frequency of mutations in cancer-related genes did not significantly differ between the two groups. Overall and recurrence-free survival were significantly worse in patients with TET2-high iCCA than in those with TET2-low iCCA. A multivariate analysis identified the high expression of TET2 as an independent prognostic factor (HR = 2.94; p = 0.007). The degree of methylation at two promoter CpG sites was significantly less in TET2-high iCCA than in TET2-low iCCA or non-cancer tissue. In conclusion, in contrast to other IDH-related neoplasms, TET2 overexpression is common in iCCA of both subtypes, and its high expression, potentially induced by promoter hypomethylation, is an independent poor prognostic factor.

Elevated serum CA19-9 indicates severe liver inflammation and worse survival after curative resection in hepatitis B-related hepatocellular carcinoma

We explored the prognostic value of preoperative CA19-9 in α-fetoprotein (AFP)-positive and -negative HCC with hepatitis B virus (HBV) background (HBV-HCC), and explored the underlying mechanism. Recurrence-free survival (RFS) and overall survival (OS) were assessed in HBV-HCC patients who underwent curative resection (Cohort 1). Immunohistochemical staining of CA19-9 in HCC and liver parenchyma were quantified in another cohort of 216 patients with resected HCC (Cohort 2). Immunohistochemical staining of CA19-9 and serum CA19-9 level was also compared between patients with HCC and intrahepatic cholangiocarcinoma (ICC) (Cohort 3). In Cohort 1, CA19-9 ≥ 39 U/mL was an independent risk factor for RFS (HR = 1.507, 95% CI = 1.087-2.091, p = 0.014) and OS (HR = 1.646, 95% CI = 1.146-2.366, p = 0.007). CA19-9 ≥ 39 U/mL was also associated with significantly higher incidence of macrovascular invasion (MaVI) compared with CA19-9 < 39 U/mL (23.0% vs. 7.2%, p = 0.002), and elevated aminotransferase and aspartate aminotransferase to platelet ratio index (APRI), and lower albumin. Immunohistochemical staining of CA19-9 revealed that CA19-9 expression was found exclusively in the background liver but not in HCC tumor cells. In contrast, tumor tissue was the main source of CA19-9 in ICC patients. CA19-9 ≥ 39 U/mL was associated with worse OS and RFS in both AFP-positive and negative HCC patients. CA19-9 indicated more severe inflammation and cirrhosis in the liver of HCC patients.

Emerging treatment evolutions and integrated molecular characteristics of biliary tract cancers

Biliary tract cancers (BTCs) consist of a group of highly heterogeneous malignancies that are characterized by genomic differences among tumors from different anatomic sites. The current treatment for BTC includes surgery, chemotherapy, target therapy, and immunotherapy. Although surgery remains the primary option for localized disease, representing the only potential curative treatment, a high risk of recurrence cannot be neglected. Chemotherapy has been considered the standard of care for both advanced and metastatic disease and in adjuvant settings. However, drug resistance is a major obstacle associated with chemotherapy. The development of genetic testing technologies, including next-generation sequencing, has opened the door for the identification of drug targets and candidate molecules. A series of preclinical studies has demonstrated the role of gene mutations, abnormal signaling pathways, and immunosuppression in the pathogenesis of BTC, laying the foundation for the application of targeted therapy and immunotherapy. A variety of molecularly targeted agents, including pemigatinib, have shown promising survival benefits in patients with advanced disease. The rapidly evolving role of multimodal therapy represents the subject of this review.

Genetic, Clinicopathological, and Radiological Features of Intrahepatic Cholangiocarcinoma with Ductal Plate Malformation Pattern

Background/Aims

Intrahepatic cholangiocarcinoma (iCCA) with a ductal plate malformation (DPM) pattern is a recently recognized rare variant. The genomic profile of iCCA with DPM pattern needs to be elucidated.

Methods

Cases of iCCA with DPM pattern were retrospectively reviewed based on the medical records, pathology slides, and magnetic resonance imaging (MRI) reports collected between 2010 to 2019 at a single center. Massive parallel sequencing was performed for >500 cancer-related genes.

Results

From a total of 175 iCCAs, five (2.9%) cases of iCCA with DPM pattern were identified. All cases were of the small duct type, and background liver revealed chronic B viral or alcoholic hepatitis. Three iCCAs with DPM pattern harbored MRI features favoring the diagnosis of hepatocellular carcinoma, whereas nonspecific imaging features were observed in two cases. All patients were alive without recurrence during an average follow-up period of 57 months. Sequencing data revealed 64 mutated genes in the five cases, among which FGFR2 and PTPRT were most frequently mutated (three cases each) including an FGFR2-TNC fusion in one case. Mutations in ARID1A and CDKN2A were found in two cases, and mutations in TP53, BAP1, ATM, NF1, and STK11 were observed in one case each. No IDH1, KRAS, or PBRM1 mutations were found.

Conclusions

iCCAs with DPM pattern have different clinico-radio-pathologic and genetic characteristics compared to conventional iCCAs. Moreover, FGFR2 and ARID1A variants were identified. Altogether, these findings further suggest that iCCA with DPM pattern represents a specific subtype of small duct type iCCA.

Novel biomarkers for cholangiocarcinoma: how can it enhance diagnosis, prognostication, and investigational drugs? Part-1

INTRODUCTION

The development of novel biomarkers for cancer has exploded over the last decade with advances in novel technologies. Cholangiocarcinoma (CCA), a cancer of the bile ducts, has a dearth of strong disease and pathophysiology biomarkers, making early detection and prognostication a difficult task.

AREAS COVERED

In this comprehensive review, we discuss the spectrum of biomarkers for CCA diagnosis and prognostication. We elaborate on novel biomarker discovery through a comprehensive multi-omics approach. We also cover, how certain biomarkers may also serve as unique and potent targets for therapeutic development.

EXPERT OPINION

Despite the relatively poor diagnostic and prognostic performance of existing biomarkers for CCA, there is a vast range of novel biomarkers with exquisite diagnostic and prognostic performance for CCA in the pipeline. Moreover, these biomarkers may serve as potential targets for precision medicine. Existing strategies to target unique biomolecular classes are discussed, within the context of an overall 'omics' focused profiling strategy. Omics profiling will simultaneously allow for enhanced biomarker development and identification of unique subtypes of cholangiocarcinoma and how they are influenced by an individual's unique context. In this manner, patient management strategy and clinical trial design can be optimized to the individual.

Cholangiocarcinoma and liver transplantation: What we know so far?

Cholangiocarcinoma (CCA) is a type of cancer with increasing prevalence around the world that originates from cholangiocytes, the epithelial cells of the bile duct. The tumor begins insidiously and is distinguished by high grade neoplasm, poor outcome, and high risk for recurrence. Liver transplantation has become broadly accepted as a treatment option for CCA. Liver transplantation is expected to play a crucial role as palliative and curative therapy for unresectable hilar CCA and intrahepatic CCA. The purpose of this study was to determine which cases with CCA should be subjected to liver transplantation instead of resection, although reported post-transplant recurrence rate averages approximately 20%. This review also aims to highlight the molecular current frontiers of CCA and directions of liver transplantation for CCA.

Structural engineering of chimeric antigen receptors targeting HLA-restricted neoantigens

Chimeric antigen receptor (CAR) T cells have emerged as a promising class of therapeutic agents, generating remarkable responses in the clinic for a subset of human cancers. One major challenge precluding the wider implementation of CAR therapy is the paucity of tumor-specific antigens. Here, we describe the development of a CAR targeting the tumor-specific isocitrate dehydrogenase 2 (IDH2) with R140Q mutation presented on the cell surface in complex with a common human leukocyte antigen allele, HLA-B*07:02. Engineering of the hinge domain of the CAR, as well as crystal structure-guided optimization of the IDH2^R140Q-HLA-B*07:02-targeting moiety, enhances the sensitivity and specificity of CARs to enable targeting of this HLA-restricted neoantigen. This approach thus holds promise for the development and optimization of immunotherapies specific to other cancer driver mutations that are difficult to target by conventional means.

Chimeric antigen receptor T cells in the clinic currently target cell-type-specific extracellular antigens on malignant cells. Here, authors engineer tumor-specific chimeric antigen receptor T cells that target human leukocyte antigen-presented neoantigens derived from mutant intracellular proteins.

IDH Mutation Subgroup Status Associates with Intratumor Heterogeneity and the Tumor Microenvironment in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is highly heterogeneous. Here, the authors perform exome sequencing and bulk RNA sequencing on 73 tumor regions from 14 ICC patients to portray the multi-faceted intratumor heterogeneity (ITH) landscape of ICC. The authors show that ITH is highly concordant across genomic, transcriptomic, and immune levels. Comparison of these data to 8 published datasets reveals significantly higher degrees of ITH in ICC than hepatocellular carcinoma. Remarkably, the authors find that high-ITH tumors highly overlap with the IDH (isocitrate dehydrogenase)-mutant subgroup (IDH-SG), comprising of IDH-mutated tumors and IDH-like tumors, that is, those IDH-wildtype tumors that exhibit similar molecular profiles to the IDH-mutated ones. Furthermore, IDH-SG exhibits less T cell infiltration and lower T cell cytotoxicity, indicating a colder tumor microenvironment (TME). The higher ITH and colder TME of IDH-SG are successfully validated by single-cell RNA sequencing on 17 503 cells from 4 patients. Collectively, the study shows that IDH mutant subgroup status, rather than IDH mutation alone, is associated with ITH and the TME of ICC tumors. The results highlight that IDH-like patients may also benefit from IDH targeted therapies and provide important implications for the diagnosis and treatment of ICC.

Significant Response to Camrelizumab Plus Targeted Drugs in Recurrent Intrahepatic Cholangiocarcinoma: a Case Report and Literature Review

Purpose

Intrahepatic cholangiocarcinoma is the second most common primary liver cancer, and is associated with a poor prognosis and rising incidence rate.

Methods

Here, we reported the case of a middle-aged Asian male who presented with a 9.5-cm liver lesion and was diagnosed with intrahepatic cholangiocarcinoma.

Results

The patient experienced recurrence three times, twice following radical resection and standard adjuvant chemotherapy and once following camrelizumab plus apatinib, after which the tumor progressed with elevated CA 19.9 level. After tissue biopsy for next-generation sequencing, apatinib was replaced by lenvatinib, and the patient achieved disease control again, with a progression-free survival of 10 months.

Conclusion

Combined immunotherapy and targeted therapy regimens are a promising approach for refractory intrahepatic cholangiocarcinoma. Further well-designed prospective clinical trials are needed to confirm the efficacy and safety. Since intrahepatic cholangiocarcinoma is characterized by high heterogeneity and with complex crosstalk among oncogenic pathways, further exploration is required to more deeply understand the mechanism of action of this treatment approach and guide individualized treatment selection.

ARID1A Variations in Cholangiocarcinoma: Clinical Significances and Molecular Mechanisms

Cholangiocarcinoma (CCA), a high mortality malignant carcinoma characterized by advanced disease and frequent recurrence, constitutes a major challenge for treatment and prognosis. AT-rich interaction domain 1A (ARID1A) variation is a distinct genetic entity in CCA, getting mounting concerns recently. Here, we comprehensively reviewed the clinical significance and molecular mechanisms of ARID1A alterations in CCA. Based on the independent data derived from 29 relevant studies, the variation rate of ARID1A in intrahepatic and extrahepatic CCA is reported at 6.9-68.2% and 5-55%, respectively. Most of the included studies (28/29, 96.6%) suggest that ARID1A serves as a tumor suppressor in CCA. ARID1A variation may be an important prognostic indicator to predict disease mortality, metastasis, and recurrence in patients with CCA. Multifactorial molecular mechanisms are involved in the relationship between ARID1A variations and the pathogenesis and pathophysiology of CCA, including disruption of the cell cycle, chromatin remodeling, oxidative stress damage, DNA hypermethylation, and the interaction of multiple genes being affected. This review describes that ARID1A variation might be a potential diagnostic and prognostic biomarker for CCA. Future diagnoses and treatments targeting ARID1A hint towards a precision medicine strategy in the management of CCA.

Intrahepatic Cholangiocarcinoma with Lymph Node Metastasis: Treatment-Related Outcomes and the Role of Tumor Genomics in Patient Selection

PURPOSE

Lymph node metastasis (LNM) drastically reduces survival after resection of intrahepatic cholangiocarcinoma (IHC). Optimal treatment is ill defined, and it is unclear whether tumor mutational profiling can support treatment decisions.

EXPERIMENTAL DESIGN

Patients with liver-limited IHC with or without LNM treated with resection (N = 237), hepatic arterial infusion chemotherapy (HAIC; N = 196), or systemic chemotherapy alone (SYS; N = 140) at our institution between 2000 and 2018 were included. Genomic sequencing was analyzed to determine whether genetic alterations could stratify outcomes for patients with LNM.

RESULTS

For node-negative patients, resection was associated with the longest median overall survival [OS, 59.9 months; 95% confidence interval (CI), 47.2-74.31], followed by HAIC (24.9 months; 95% CI, 20.3-29.6), and SYS (13.7 months; 95% CI, 8.9-15.9; P < 0.001). There was no difference in survival for node-positive patients treated with resection (median OS, 19.7 months; 95% CI, 12.1-27.2) or HAIC (18.1 months; 95% CI, 14.1-26.6; P = 0.560); however, survival in both groups was greater than SYS (11.2 months; 95% CI, 14.1-26.6; P = 0.024). Node-positive patients with at least one high-risk genetic alteration (TP53 mutation, KRAS mutation, CDKN2A/B deletion) had worse survival compared to wild-type patients (median OS, 12.1 months; 95% CI, 5.7-21.5; P = 0.002), regardless of treatment. Conversely, there was no difference in survival for node-positive patients with IDH1/2 mutations compared to wild-type patients.

CONCLUSIONS

There was no difference in OS for patients with node-positive IHC treated by resection versus HAIC, and both treatments had better survival than SYS alone. The presence of high-risk genetic alterations provides valuable prognostic information that may help guide treatment.

Prognostic Value of Inflammatory and Tumour Markers in Small-Duct Subtype Intrahepatic Cholangiocarcinoma after Curative-Intent Resection

Intrahepatic cholangiocarcinoma (ICC) is characterised by heterogeneity, and it can be subdivided into small-duct and large-duct types. Inflammatory and tumour markers could effectively predict prognosis in many cancers, but no similar studies have been conducted in the histological subtypes of ICC. A total of 102 and 72 patients with ICC undergoing curative-intent resection were retrospectively subclassified into large-duct and small-duct types by chemical staining, respectively. The prognostic value of inflammatory and tumour markers was studied for the first time in histological subtypes of ICC by using a Cox regression model. A novel predictor named prognostic inflammatory index (PII) was proposed and defined as neutrophil × monocyte/lymphocyte count (10⁹/L). Survival analysis showed that PII, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), CA242, and ferritin were all predictors of DFS and OS in patients with ICC (P < 0.040). Subgroup analysis showed that PII, CA19-9, and ferritin were risk predictors of disease-free survival (DFS) and overall survival (OS) in small-duct type ICC (P < 0.015). In addition, in small-duct type ICC, NLR and LMR were correlated with OS (P < 0.025), whilst CEA and CA242 were correlated with DFS (P ≤ 0.010). In conclusion, PII is a convenient and efficient inflammatory predictor of DFS and OS in ICCs and their small-duct type. NLR and LMR, rather than platelet-to-lymphocyte ratio, were correlated with OS in small-duct type ICC. In addition, ferritin may be a supplement to CA19-9 in stratifying the survival outcome of patients with small-duct type ICC.

Novel Targeted Therapies for Advanced Cholangiocarcinoma

Cholangiocarcinoma (CCA) includes a group of rare and aggressive hepatobiliary malignancies, including extrahepatic cholangiocarcinoma (eCCA) and intrahepatic cholangiocarcinoma (iCCA), with the former further subdivided into distal (dCCA) and perihilar cholangiocarcinoma (pCCA) [...].

Clinically significant genomic alterations in the Chinese and Western patients with intrahepatic cholangiocarcinoma

BACKGROUND

The goal of this study is to disclose the clinically significant genomic alterations in the Chinese and Western patients with intrahepatic cholangiocarcinoma.

METHODS

A total of 86 Chinese patients were enrolled in this study. A panel of 579 pan-cancer genes was sequenced for the qualified samples from these patients. Driver genes, actionability, and tumor mutational burden were inferred and compared to a cohort of Western patients.

RESULTS

Totally, 36 and 12 driver genes were identified in the Chinese and Western cohorts, respectively. Of them, seven driver genes (IDH1, KRAS, TP53, BAP1, PBRM1, ARID1A, and NRAS) were shared by the two cohorts. Four driver genes (SPTA1, ARID2, TP53, and GATA1) were found significantly correlated with the tumor mutational burden. For both cohorts, half of the patients had actionable mutations. The two cohorts shared the most actionable genes but differed much in their frequency. Though KRAS mutations were at the first and second actionable rank respectively for the Chinese and Western populations, they were still at a relatively low level of actionable evidence.

CONCLUSIONS

The study on the clinical significance of genomic alterations directs the future development of precision medicine for intrahepatic cholangiocarcinoma treatment.

Comprehensive analysis of genomic mutation signature and tumor mutation burden for prognosis of intrahepatic cholangiocarcinoma

Background

Intrahepatic cholangiocarcinoma (iCCA) is a highly lethal malignancy of the biliary tract. Analysis of somatic mutational profiling can reveal new prognostic markers and actionable treatment targets. In this study, we explored the utility of genomic mutation signature and tumor mutation burden (TMB) in predicting prognosis in iCCA patients.

Methods

Whole-exome sequencing and corresponding clinical data were collected from the ICGC portal and cBioPortal database to detect the prognostic mutated genes and determine TMB values. To identify the hub prognostic mutant signature, we used Cox regression and Lasso feature selection. Mutation-related signature (MRS) was constructed using multivariate Cox regression. The predictive performances of MRS and TMB were assessed using Kaplan–Meier (KM) analysis and receiver operating characteristic (ROC). We performed a functional enrichment pathway analysis using gene set enrichment analysis (GSEA) for mutated genes. Based on the MRS, TMB, and the TNM stage, a nomogram was constructed to visualize prognosis in iCCA patients.

Results

The mutation landscape illustrated distributions of mutation frequencies and types in iCCA, and generated a list of most frequently mutated genes (such as Tp53, KRAS, ARID1A, and IDH1). Thirty-two mutated genes associated with overall survival (OS) were identified in iCCA patients. We obtained a six-gene signature using the Lasso and Cox method. AUCs for the MRS in the prediction of 1-, 3-, and 5-year OS were 0.759, 0.732, and 0.728, respectively. Kaplan–Meier analysis showed a significant difference in prognosis for patients with iCCA having a high and low MRS score (P < 0.001). GSEA was used to show that several signaling pathways, including MAPK, PI3K-AKT, and proteoglycan, were involved in cancer. Conversely, survival analysis indicated that TMB was significantly associated with prognosis. GSEA indicated that samples with high MRS or TMB also showed an upregulated expression of pathways involved in tumor signaling and the immune response. Finally, the predictive nomogram (that included MRS, TMB, and the TNM stage) demonstrated satisfactory performance in predicting survival in patients with iCCA.

Conclusions

Mutation-related signature and TMB were associated with prognosis in patients with iCCA. Our study provides a valuable prognostic predictor for determining outcomes in patients with iCCA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07788-7.

PD-L1, TMB, MSI, and Other Predictors of Response to Immune Checkpoint Inhibitors in Biliary Tract Cancer

Biliary tract cancer (BTC) represents the second most frequently diagnosed primary liver cancer worldwide following hepatocellular carcinoma, and the overall survival of patients with unresectable disease remains poor. In recent years, the advent of immune checkpoint inhibitors (ICIs) has revolutionized the therapeutic landscape of several malignancies with these agents, which have also been explored in advanced BTC, as monotherapy or in combination with other anticancer agents. However, clinical trials evaluating ICIs in BTC have shown conflicting results, and the clinical benefit provided by immunotherapy seems limited to a small subgroup of BTC patients. Thus, the identification of reliable predictors of the response to immunotherapy represents a significant challenge in this setting. This review provides an overview of the available evidence on the biomarkers predictive of the response to ICIs in patients with advanced BTC, especially focusing on programmed death-ligand 1 (PD-L1), tumor mutational burden (TMB), microsatellite instability (MSI), and other emerging biomarkers.

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

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

High expression of HVEM is associated with improved prognosis in intrahepatic cholangiocarcinoma

Herpesvirus entry mediator (HVEM) displays dual signals in T-cell activation according to the ligands and intracytoplasmic effectors it interacts with. High HVEM expression may play an immunosuppressive role in several malignancies. The present study investigated the clinical impact of HVEM on intrahepatic cholangiocarcinoma (ICC), including its prognostic value, and association with clinicopathological features and immune status. The clinical data of 102 consecutive patients with ICC who underwent surgical treatment from January 2012 to December 2017 were collected. The expression of HVEM and different types of tumor-infiltrating lymphocytes (TILs) were investigated in ICC tissue samples by immunohistochemical staining. HVEM expression was detected in the tumor tissues of 92 (90.2%) patients with ICC. Patients with high HVEM expression were more likely to have increased peripheral blood lymphocyte (PBL) concentrations (P=0.031), decreased CEA (P=0.036), low TNM stage (P=0.043) and high frequencies of small-duct histological type (P=0.021) and BAP1 retained expression (P=0.010). Survival analysis showed that high HVEM expression was a favorable independent predictor of overall postoperative survival (P=0.034, hazard ratio=0.486, 95% confidence interval=0.249–0.945). In addition, no significant association of HVEM expression with CD4⁺ (P=0.512), CD8⁺ (P=0.750) or CD45RO⁺ (P=0.078) TILs was identified in the ICC tissues. These results indicate that HVEM may serve as a favorable prognostic marker for ICC. Furthermore, co-stimulatory signals from HVEM may play a dominant role in the progression of ICCs, which can be explained by an increase in the number of PBLs rather than a change in the number of TILs. However, the function of the HVEM network in ICC progression is complex and requires further study.

Molecular Features and Targeted Therapies in Extrahepatic Cholangiocarcinoma: Promises and Failures

Biliary tract cancers (BTCs) include a heterogenous group of aggressive malignancies with limited therapeutic options. According to their anatomical location, these hepatobiliary tumors are usually classified into intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA), and gallbladder cancer (GBC). Unfortunately, BTCs are often diagnosed when already metastatic, and although the advent of genomic sequencing has led to a deeper understanding of iCCA pathogenesis, very little data are currently available about the molecular landscape of eCCA. Moreover, despite novel systemic treatments emerging in BTC, the grim prognosis of eCCA patients has not changed in the past decade, and no targeted therapies have been approved so far. The aim of the current review is to provide an overview regarding molecular features and potential targeted therapies in eCCA, together with novel therapeutic approaches and future directions of translational and clinical research on this highly aggressive disease that poses many unanswered questions.

Molecular epidemiology of IDH2 hotspot mutations in cancer and immunohistochemical detection of R172K, R172G, and R172M variants

IDH1/2 hotspot mutations occur in glioma, cholangiocarcinoma, chondrosarcoma, sinonasal carcinoma, and T-cell lymphoma and have diagnostic, prognostic, and/or therapeutic value. Availability of immunohistochemistry (IHC) protocols for specific IDH2 mutation detection is limited. A targeted exome sequencing assay MSK-IMPACT cohort comprising >38,000 cancer cases was explored for the presence of IDH1/2 mutations in solid malignancies and select T-cell lymphomas. Seventy-four formalin-fixed paraffin-embedded IDH1/2-mutated (n = 62) and wild-type (n = 12) samples were used for testing and optimization of anti-IDH2 monoclonal antibodies (mAbs) 14H7, 3C11, and MMab1 targeting R172K, R172G, and R172M mutant proteins, respectively. IDH1/2 mutations were common in glioma (26.8% and 1.6%), intrahepatic cholangiocarcinoma (23.1% and 5.7%), chondrosarcoma (19.4% and 10.7%), sinonasal undifferentiated/large-cell neuroendocrine carcinoma (0% and 84.2%), angioimmunoblastic T-cell lymphoma (0% and 22%), and peripheral T-cell lymphoma (0 and 5.1%). In other cancers, IDH2 mutations were rare. IDH2 R172 variants included R172K (39%), R172S (29%), R172W (12%), R172G (10%), R172M (5%), and R172T (4%). 14H7, 3C11, and MMab1 detected all IDH2 R172K, R172G, and R172M, respectively, and produced a crisp, granular cytoplasmic staining pattern. 3C11 was also positive in 5 of 6 IDH1 R132G mutants showing a homogeneous, smooth cytoplasmic staining. All 3 mAbs were negative in other IDH1/2 mutant or wild-type cases. IHC using mAbs 14H7, 3C11, and MMab1 can facilitate molecular diagnosis as a reliable, fast, and inexpensive alternative for specific IDH2 variant detection. Given the distinct distribution of IDH2 R172 mutations in cancers, these mAbs could also serve as useful pathologic diagnostic markers.

High platelet-to-lymphocyte ratio is associated with poor prognosis in patients with unresectable intrahepatic cholangiocarcinoma receiving gemcitabine plus cisplatin

BACKGROUND

Several systemic inflammatory response (SIR) markers, including platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and albumin-to-globulin ratio (AGR), have emerged as prognostic markers in various cancers. The aim of this study was to explore the impact of SIR markers on the survival outcomes of unresectable intrahepatic cholangiocarcinoma (IHC) patients.

METHODS

Patients with histologically confirmed, unresectable IHC treated with gemcitabine plus cisplatin (GP) chemotherapy in a single tertiary hospital from 2012 to 2016 were retrospectively reviewed. Progression-free survival (PFS) and overall survival (OS) were determined using unadjusted Kaplan-Meier and adjusted Cox-proportional-hazards analysis. Time-dependent receiver operating characteristic (ROC) analysis was performed to compare the performance of the SIR markers in predicting OS.

RESULTS

A total of 137 patients received a median of six cycles (interquartile range [IQR], 3-11) of GP chemotherapy with a median observation time of 9.9 months (range, 1.8-54.7 months). The median PFS and OS of all patients were 7.8 months and 9.9 months, respectively. Among the SIR markers, high PLR (> 148) and high NLR (> 5) were associated with a short PFS (Hazard ratio [HR] 1.828, P = 0.006; HR 1.738, P = 0.030, respectively) and short OS (HR 2.332, P < 0.001; HR 2.273, P < 0.001, respectively). Low LMR (< 3.5) and low AGR (< 1.2) were associated with a short OS (HR 2.423, P < 0.001; HR 1.768, P = 0.002, respectively). In multivariable cox-regression analysis, high PLR (HR 1.766, P = 0.009) and distant lymph node (LN) metastasis (HR 2.085, P = 0.001) were associated with a short PFS. High PLR (HR 1.856, P = 0.002) was an independent predictor of a short OS, along with distant LN metastasis (HR 1.929; P < 0.001), low LMR (HR 1.691; P = 0.041), and low level of serum albumin (< 3.5 g/dL) (HR 1.632; P = 0.043). Time-dependent ROC analysis revealed that the area under the curve of PLR for predicting overall survival was greater than that of NLR, LMR, and AGR at most time points.

CONCLUSIONS

High PLR was an independent prognostic factor of a short PFS and OS in patients with unresectable IHC receiving GP chemotherapy.

Targeted Therapies in Advanced Biliary Tract Cancer: An Evolving Paradigm

Biliary tract cancers (BTCs) are a heterogeneous group of adenocarcinomas that originate from the epithelial lining of the biliary tree. BTCs are characterized by presentation with advanced disease precluding curative surgery, rising global incidence, and a poor prognosis. Chemotherapy is the mainstay of the current treatment, which results in a median overall survival of less than one year, underscoring the need for novel therapeutic agents and strategies. Next-generation sequencing-based molecular profiling has shed light on the underpinnings of the complex pathophysiology of BTC and has uncovered numerous actionable targets, leading to the discovery of new therapies tailored to the molecular targets. Therapies targeting fibroblast growth factor receptor (FGFR) fusion, isocitrate dehydrogenase (IDH) mutations, the human epidermal growth factor receptor (HER) family, DNA damage repair (DDR) pathways, and BRAF mutations have produced early encouraging results in selected patients. Current clinical trials evaluating targeted therapies, as monotherapies and in combination with other agents, are paving the way for novel treatment options. Genomic profiling of cell-free circulating tumor DNA that can assist in the identification of an actionable target is another exciting area of development. In this review, we provide a contemporaneous appraisal of the evolving targeted therapies and the ongoing clinical trials that will likely transform the therapeutic paradigm of BTC.