Molecular Landscape and Therapeutic Strategies in Cholangiocarcinoma: An Integrated Translational Approach towards Precision Medicine

Biliary stem cells in health and cholangiopathies and cholangiocarcinoma

PURPOSE OF REVIEW

This review discusses evidence regarding progenitor populations of the biliary tree in the tissue regeneration and homeostasis, and the pathobiology of cholangiopathies and malignancies.

RECENT FINDINGS

In embryogenesis biliary multipotent progenitor subpopulation contributes cells not only to the pancreas and gall bladder but also to the liver. Cells equipped with a constellation of markers suggestive of the primitive endodermal phenotype exist in the peribiliary glands, the bile duct glands, of the intra- and extrahepatic bile ducts. These cells are able to be isolated and cultured easily, which demonstrates the persistence of a stable phenotype during in vitro expansion, the ability to self-renew in vitro, and the ability to differentiate between hepatocyte and biliary and pancreatic islet fates.

SUMMARY

In normal human livers, stem/progenitors cells are mostly restricted in two distinct niches, which are the bile ductules/canals of Hering and the peribiliary glands (PBGs) present inside the wall of large intrahepatic bile ducts. The existence of a network of stem/progenitor cell niches within the liver and along the entire biliary tree inform a patho-biological-based translational approach to biliary diseases and cholangiocarcinoma since it poses the basis to understand biliary regeneration after extensive or chronic injuries and progression to fibrosis and cancer.

Pathology of Cholangiocarcinomas

Cholangiocarcinomas (CCA) are heterogeneous tumors that arise from epithelial cells of the biliary tract. They represent the second primary liver malignancy, after hepatocellular carcinoma. Recent epidemiological data show an increased incidence of intrahepatic CCA without any identified causes. According to their location on the biliary tract, intrahepatic, perihilar (p) and distal (d) CCA can be individualized. Intrahepatic CCA (iCCA) are subdivided into small duct type iCCA and large duct type iCCA, according to the level or size of the biliary duct affected. These two subgroups are characterized by distinct risk factors, gross aspect, histopathological and molecular features, and therapeutic management. The role of biopsy in iCCA is to confirm the diagnosis and to eliminate various differential diagnostics, in particular, metastases. In p/d CCA, biopsy requires more invasive approaches, and tissue samples are difficult to obtain, leading to a high rate of false negatives. In this review, we will discuss the different classifications of CCA (anatomical and macroscopic). We will describe the various microscopic and phenotypic subtypes of CCA. Finally, we will deal with their mode of extension, the role of biopsy and pre-neoplastic lesions.

Combining of chemotherapy with targeted therapy for advanced biliary tract cancer: A systematic review and meta-analysis

BACKGROUND

Targeted therapy (TT) has resulted in controversial efficacy as first-line treatment for biliary tract cancer (BTC). More efficacy comparisons are required to clarify the overall effects of chemotherapy (CT) combined with TT and CT alone on advanced BTC.

AIM

To conduct a meta-analysis of the available evidence on the efficacy of CT combined with TT for advanced BTC.

METHODS

The PubMed, EMBASE, ClinicalTrials, Scopus and Cochrane Library databases were systematically searched for relevant studies published from inception to August 2022. Only randomized clinical trials (RCTs) including comparisons between the combination of gemcitabine-based CT with TT and CT alone as first-line treatment for advanced BTC were eligible (PROSPERO-CRD42022313001). The odds ratios (ORs) for the objective response rate (ORR) and hazard ratios (HRs) for both progression-free survival (PFS) and overall survival (OS) were calculated and analyzed. Subgroup analyses based on different targeted agents, CT regimens and tumor locations were prespecified.

RESULTS

Nine RCTs with a total of 1361 individuals were included and analyzed. The overall analysis showed a significant improvement in ORR in patients treated with CT + TT compared to those treated with CT alone (OR = 1.43, 95%CI: 1.11-1.86, P = 0.007) but no difference in PFS or OS. Similar trends were observed in the subgroup treated with agents targeting epidermal growth factor receptor (OR = 1.67, 95%CI: 1.17-2.37, P = 0.004) but not in the subgroups treated with agents targeting vascular endothelial growth factor receptor or mesenchymal-epithelial transition factor. Notably, patients who received a CT regimen of gemcitabine + oxaliplatin in the CT + TT arm had both a higher ORR (OR = 1.75, 95%CI: 1.20-2.56, P = 0.004) and longer PFS (HR = 0.83, 95%CI: 0.70-0.99, P = 0.03) than those in the CT-only arm. Moreover, patients with cholangiocarcinoma treated with CT + TT had significantly increased ORR and PFS (ORR, OR = 2.06, 95%CI: 1.27-3.35, PFS, HR = 0.79, 95%CI: 0.66-0.94).

CONCLUSION

CT + TT is a potential first-line treatment for advanced BTC that leads to improved tumor control and survival outcomes, and highlighting the importance of CT regimens and tumor types in the application of TT.

Precision Medicine in Cholangiocarcinoma: Past, Present, and Future

Cholangiocarcinoma (CCA), or biliary tract cancer, has a poor prognosis. The median survival time among patients with CCA is under 2 years from diagnosis, and the global 5-year survival rate is only 10%. First-line therapy with chemotherapeutic agents, gemcitabine plus cisplatin, has traditionally been used to treat unresectable advanced CCA. In recent years, precision medicine has become a mainstream cancer treatment due to innovative next-generation sequencing technology. Several genetic alterations, including mutations, gene fusions, and copy number variations, have been found in CCA. In this review, we summarized the current understanding of genetic profiling in CCA and targeted therapy in CCA. Owing to the high heterogeneity of CCA, tumor microenvironmental factors, and the complexity of tumor biology, only pemigatinib, infigratinib, ivosidenib, larotrbctinib, and entrectinib are currently approved for the treatment of CCA patients with fibroblast growth factor receptor 2 gene (FGFR2) fusion, isocitrate dehydrogenase gene (IDH1) mutation, and neurotrophin receptor tyrosine kinase gene (NRTK) fusion, respectively. Additional targeted therapies, including other FGFR2 inhibitors, PI3K/AKT/mTOR inhibitors, and BRAF-directed targeted therapy, have been discussed for the management of CCA, and immune checkpoint inhibitors, particularly pembrolizumab, can be administered to patients with high microsatellite instability tumors. There is a further need for improvement in precision medicine therapies in the treatment of CCA and discuss the approved and potential targeted therapies for CCA.

Real-World Outcomes of Gemcitabine, Cisplatin, and Nab-Paclitaxel Chemotherapy Regimen for Advanced Biliary Tract Cancer: A Propensity Score-Matched Analysis

Background/Aims

Advanced biliary tract cancer (BTC) is associated with poor survival. A recent phase II study of triplet combination chemotherapy, including gemcitabine, cisplatin, and nanoparticle albumin-bound (nab)-paclitaxel, has shown promising results. This study aimed to compare the efficacy of triplet and standard doublet chemotherapy in a real-world setting.

Methods

Patients with advanced BTC treated with triplet and doublet chemotherapy regimens were recruited. The propensity-score nearest neighbor matching method with a ratio of one-to-one was used to create a matched cohort for comparison. Progression-free survival (PFS), overall survival (OS), and safety profiles were examined in both groups.

Results

A total of 68 patients (n=34 per group) were included in the matched cohort, and their baseline characteristics were well balanced. Survival outcomes in the triplet chemotherapy group were not better than those in the doublet chemotherapy group, with a median PFS of 7.5 months (95% confidence interval [CI], 4.1 to 10.9) versus 7.2 months (95% CI, 5.6 to 8.9) (hazard ratio [HR], 0.93; 95% CI, 0.53 to 1.62; p=0.793) and a median OS of 13.7 months (95% CI, 8.8 to 18.7) versus 12.2 months (95% CI, 8.4 to 16.0) (HR 0.73; 95% CI, 0.38 to 1.41; p=0.354), respectively. In addition, the treatment-related severe adverse events, such as neutropenia, were more common in the triplet chemotherapy group.

Conclusions

Gemcitabine, cisplatin, and nab-paclitaxel did not improve the PFS or OS compared to that achieved by standard chemotherapy in patients with advanced BTC. The benefits of triplet chemotherapy in advanced BTC require examination in large randomized controlled trials.

Key Words Biliary tract cancer; Gemcitabine; Cisplatin; Albumin-bound paclitaxel

A review of molecularly targeted therapy in biliary tract carcinoma: what is the next step?

Patients with unresectable biliary tract carcinomas (BTCs) have a poor prognosis with a median overall survival of fewer than 12 months following systemic chemotherapy. In recent years, the identification of distinct molecular alterations with corresponding targeted therapies is modifying this therapeutic algorithm. The aim of this review is to present an overview of targeted therapy for BTCs, describing published available data and potential future challenges in ongoing trials. From clinicaltrials.gov online database all ongoing trials for BTCs (any stage) was examinated in July 2021, and data regarding study design, disease characteristics and type of treatments were registered. Oncogenic-driven therapy (targeted therapy) was investigated in 67 trials. According to research, 15 ongoing trials (22.4%) are investigating fibroblast growth factor (FGF) receptor (FGFR)-inhibitors in BTCs. Three (18.7%) are open-label randomized multicenter phase 3 trials, 8 (50%) are single-arm phase two trials, and 4 (25%) are phase one studies. Twelve (17.9%) clinical trials dealt with isocitrate dehydrogenase (IDH) 1/2 targeting therapy either in combination with cisplatin (Cis) and gemcitabine (Gem) as first-line treatment for BTCs or in monotherapy in patients with IDH1 mutant advanced malignancies, including cholangiocarcinoma (CCA). Nine (13.4%) clinical trials tested human epidermal growth factor receptor (HER) 2 targeting therapy. Four (44.4%) studies are phase I trials, two (22.2%) are phase I/II trials, and three (33.3%) phase II trials. Rare molecular alterations in BTCs, such as anaplastic lymphoma kinase (ALK), c-ros oncogene1 receptor tyrosine kinase (ROS1), and v-RAF murine sarcoma viral oncogene homologue B1 (BRAF), are also under investigation in a few trials. Forty-four clinical trials (17.2%) are investigating not oncogenic-driven multitarget therapy like multireceptor tyrosin kinase inhibitors and antiangiogenetic agents. In conclusion, this review shows that BTCs management is experiencing important innovations, especially in biomarker-based patient selection and in the new emerging therapeutic approach. Many ongoing trials could answer questions regarding the role of molecular inhibitors leading to new therapeutic frontiers for molecular subcategories of BTCs.

Identification of a novel mutation gene signature HAMP for cholangiocarcinoma through comprehensive TCGA and GEO data mining

Cholangiocarcinoma (CHOL), the second most common malignant liver tumor, is clinically heterogeneous. In this study, we used gene expression profiles of CHOL obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases to identify novel mutation signatures in CHOL. Hepcidin antimicrobial peptide (HAMP) was identified as a novel diagnostic biomarker for CHOL using the intersection of mutation analysis and receiver operating characteristic (ROC) analysis. We then explored the expression signatures of HAMP in CHOL. HAMP-related differentially expressed genes (DEGs) were selected for the identification of hub genes related to HAMP and for prognostic prediction model analysis. Gene set enrichment analysis (GSEA) showed that the HAMP-related DEGs were mainly enriched for signaling pathways related to cholangiocarcinoma development. Through immunohistochemistry validation, clinical cohorts analysis, and TCGA analysis, we investigated the association between HAMP and clinical parameters and found that decreased HAMP expression was correlated with advanced pathological grade and poor prognosis. Besides, we estimated the immune infiltration level in CHOL and its relationship with HAMP expression. The proportion of tumor-infiltrating cells revealed that gamma delta T cells and monocytes were positively correlated with HAMP expression. Besides, HAMP was also correlated with chemokine, CCL16. This evidence suggested that HAMP might contribute to immune activation in the CHOL microenvironment. Therefore, HAMP may play a synergistic role with these immune cells and chemokines to inhibit CHOL development. HAMP serves as a valuable biomarker in CHOL and is closely correlated with its progression.