Cholangiocarcinoma: from molecular biology to treatment

Unveil Intrahepatic Cholangiocarcinoma Heterogeneity through the Lens of Omics and Multi-Omics Approaches

Intrahepatic cholangiocarcinoma (iCCA) is recognized worldwide as the second leading cause of morbidity and mortality among primary liver cancers, showing a continuously increasing incidence rate in recent years. iCCA aggressiveness is revealed through its rapid and silent intrahepatic expansion and spread through the lymphatic system leading to late diagnosis and poor prognoses. Multi-omics studies have aggregated information derived from single-omics data, providing a more comprehensive understanding of the phenomena being studied. These approaches are gradually becoming powerful tools for investigating the intricate pathobiology of iCCA, facilitating the correlation between molecular signature and phenotypic manifestation. Consequently, preliminary stratifications of iCCA patients have been proposed according to their "omics" features opening the possibility of identifying potential biomarkers for early diagnosis and developing new therapies based on personalized medicine (PM). The focus of this review is to provide new and advanced insight into the molecular pathobiology of the iCCA, starting from single- to the latest multi-omics approaches, paving the way for translating new basic research into therapeutic practices.

Role of genetic testing in hepatic, pancreatic, and biliary cancers

Hepatic, pancreatic, and biliary (HPB) cancers, including hepatocellular carcinoma (HCC), pancreatic ductal adenocarcinoma (PDAC), and cholangiocarcinoma (CCA) cause a disproportionate amount of the global cancer-related mortality. Despite advances in surgical technique and improved systemic therapies, overall 5-year survival remains dismal, especially for patients with pancreatic and biliary cancer. Historically, systemic therapies for patients with HPB cancers were administered in a "one-size-fits-all" approach due to limited reliable data on efficacy for specific patient populations. However, recent advances in genetic testing techniques have greatly improved our understanding of HPB oncogenesis, shedding light on specific genetic mutations responsible for progression from physiologic cellular regulation to uninhibited cellular replication and invasive cancer. Investigations into the oncogenesis of HPB cancers have revealed multiple actionable genetic variants, as well as increased susceptibilities to currently available systemic therapies. For example, patients with PDAC and a known BRCA mutation are more likely to benefit from FOLFIRINOX or gemcitabine plus cisplatin. While patients with CCA and a IDH1 mutation may benefit from ivosidenib. As a result, many national and societal guidelines now recommend some form of genetic testing in the workup of patients with HPB cancers. We herein review the role of genetic testing in these aggressive cancers including DNA sequencing techniques, clinically relevant mutations, therapeutic implications, and current clinical recommendations.

Changing incidence and survival of intrahepatic cholangiocarcinoma based on Surveillance, Epidemiology, and End Results Database (2000-2017)

Backgrounds/Aims

Historically, the incidence and prognosis of patients diagnosed with intrahepatic cholangiocarcinoma (ICC) have been inadequately understood. Survival analysis in ICC has yet to be investigated in a population-based study.

Methods

We conducted a retrospective cohort study using the Surveillance, Epidemiology, and End Results Program (SEER) 18 Registry. Risk ratios were estimated via Poisson regression. Hazard ratios for 5-year survival were estimated using hierarchical Cox regression models.

Results

Males show a higher rate of age-adjusted ICC incidence. Blacks carried a decreased risk of ICC diagnosis than Whites, while Asians revealed a higher risk of ICC diagnosis when compared with Whites. The observed survival rates at 12, 36, and 60 months were 36.3%, 12.8%, and 8.1%, respectively. Compared with Whites, Blacks showed an increased risk of death (p < 0.01). Lymph node resection during surgery was associated with a 64.1% reduced risk of mortality (p < 0.01). A higher T stage at diagnosis was associated with poor survival (p < 0.01). Surgery combined with chemoradiotherapy, radiotherapy, or chemotherapy was associated with a reduced risk of mortality compared with nonsurgical interventions (p < 0.01).

Conclusions

ICC incidence has been increasing since 2000, especially in White males. The risk of ICC rises with age. Lymph node removal is associated with better survival. In recent years, survival had worsened, and surgical intervention improved survival compared with nonsurgical management.

[The role of molecular genetic factors in the development of cholangiocellular carcinoma]

The article lists the main inducers of cholangiocarcinogenesis. The main inflammatory mediators (IL-6, nitric oxide, COX2) have been considered. Data on the study of gene mutations in cholangiocarcinomas are presented. The spectrum of genetic mutations depends on the biliary cancer origin (FGFR2 with intrahepatic cholangiocarcinoma, PRKACA, PRKACB with extrahepatic cholangiocarcinoma). Mutations in the KRAS, TP53, ARIAD1A genes are common in extrahepatic bile duct cancer. The role of epigenetic changes such as DNA hypermethylation, histone modifications, chromatin remodeling, as well as disturbances in miRNA expression is presented. A number of epigenetic features, such as the presence of a TP53 mutations with hypermethylation of p14ARF, DAPK, and/or ASC, correlate with a more aggressive course of the disease. The role of the SOX17 gene in the development of drug resistance is highlighted. The study of the molecular genetic features of extrahepatic bile duct cancer can help to better understand the pathogenesis of this type of tumor, to establish new prognostic and diagnostic markers of the disease.

Biomarkers and Genetic Markers of Hepatocellular Carcinoma and Cholangiocarcinoma-What Do We Already Know

Simple Summary

Hepatocellular carcinoma and cholangiocarcinoma continue to remain a serious threat. In this review, we describe the most common biomarkers and genetic markers currently used in the diagnosis of hepatocellular carcinoma and cholangiocarcinoma. It can be observed that biomarkers and genetic markers might be applied in various parts of diagnosis including screening tests in a high-risk group, non-invasive detection, control of therapy, treatment selection, and control of recurrence. Also, it can be seen that nowadays there is a need for more specific markers that would improve the detection in early or very early stages of both types of cancers and further research should be focused on it.

Abstract

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with an increasing worldwide mortality rate. Cholangiocarcinoma (CCA) is the second most common primary liver cancer. In both types of cancers, early detection is very important. Biomarkers are a relevant part of diagnosis, enabling non-invasive detection and control of cancer recurrence, as well as in the application of screening tests in high-risk groups. Furthermore, some of these biomarkers are useful in controlling therapy and treatment selection. Detection of some markers presents higher sensitivity and specificity in combination with other markers when compared with a single detection. Some gene aberrations are also prognostic markers in the two types of cancers. In the following review, we discuss the most common biomarkers and genetic markers currently being used in the diagnosis of hepatocellular carcinoma and cholangiocarcinoma.

Patient-Derived Organoids of Cholangiocarcinoma

Cholangiocarcinoma (CC) is an aggressive malignancy with an inferior prognosis due to limited systemic treatment options. As preclinical models such as CC cell lines are extremely rare, this manuscript reports a protocol of cholangiocarcinoma patient-derived organoid culture as well as a protocol for the transition of 3D organoid lines to 2D cell lines. Tissue samples of non-cancer bile duct and cholangiocarcinoma were obtained during surgical resection. Organoid lines were generated following a standardized protocol. 2D cell lines were generated from established organoid lines following a novel protocol. Subcutaneous and orthotopic patient-derived xenografts were generated from CC organoid lines, histologically examined, and treated using standard CC protocols. Therapeutic responses of organoids and 2D cell lines were examined using standard CC agents. Next-generation exome and RNA sequencing was performed on primary tumors and CC organoid lines. Patient-derived organoids closely recapitulated the original features of the primary tumors on multiple levels. Treatment experiments demonstrated that patient-derived organoids of cholangiocarcinoma and organoid-derived xenografts can be used for the evaluation of novel treatments and may therefore be used in personalized oncology approaches. In summary, this study establishes cholangiocarcinoma organoids and organoid-derived cell lines, thus expanding translational research resources of cholangiocarcinoma.

The value of lymphadenectomy in surgical resection of perihilar cholangiocarcinoma: a systematic review and meta-analysis

Surgical resection is the only potentially curative treatment for patients with resectable perihilar cholangiocarcinoma (PHC). There is still no consensus on the value of lymphadenectomy despite evidence indicating lymph node (LN) status is an important prognostic indicator for postoperative long-term survival. We sought to perform a meta-analysis to summarize the current evidence on the value of lymphadenectomy among patients undergoing surgery for PHC. The PubMed (OvidSP), Embase and Cochrane Library were systematically searched for studies published before July 2020 that reported on lymphadenectomy at the time of surgery for PHC after curative surgery. 7748 patients from 28 studies were included in the meta-analysis. No survival benefit was identified with increased number of LN resected (all P > 0.05). Meanwhile, overall LN status was an important prognostic factor. Patients with lymph node metastasis had a pooled estimate hazard ratio of death that was over two-fold higher than patients without lymph node metastasis (HR 2.07, 95% CI 1.65-2.59, P < 0.001). The examination of 5 LNs on histology was associated with better staging of lymph node status and stratification of patients into positive or negative LN groups. While the extent of LN dissection was not associated with a survival benefit, examination of more than 5 LNs better staged patients into positive or negative LN groups with a lower risk of nodal understaging.

Circ_HIPK3 Knockdown Inhibits Cell Proliferation, Migration and Invasion of Cholangiocarcinoma Partly via Mediating the miR-148a-3p/ULK1 Pathway

Background

The incidence of cholangiocarcinoma (CCA) is on the rise in recent years, and its pathogenesis may be associated with the deregulation of circular RNAs (circRNAs). Hence, we aimed to investigate the role of circRNA homeodomain interacting protein kinase 3 (circ_HIPK3) in CCA.

Methods

The expression of circ_HIPK3, miR-148a-3p and unc-51 like kinase 3 (ULK1) mRNA was detected using quantitative real-time polymerase chain reaction (qPCR). The role of circ_HIPK3 in cell proliferation was detected by 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) assay and colony formation assay. Cell apoptosis and cell cycle progression were investigated using flow cytometry assay. Cell migration and invasion were detected by transwell assay. The protein levels of ULK1 and migration/invasion-associated markers were measured using Western blot. The putative relationship between miR-148a-3p and circ_HIPK3 or ULK1 was validated by dual-luciferase reporter assay. The role of circ_HIPK3 was also investigated in vivo.

Results

Circ_HIPK3 was overexpressed in CCA tissues and cells. In function, circ_HIPK3 knockdown inhibited CCA cell proliferation, migration and invasion and induced apoptosis and cycle arrest. It was confirmed that miR-148a-3p was a target of circ_HIPK3, and ULK1 was a target of miR-148a-3p. Circ_HIPK3 regulated ULK1 expression by targeting miR-148a-3p. Rescue experiments showed that miR-148a-3p inhibition reversed the effects of circ_HIPK3 knockdown. Besides, miR-148a-3p enrichment-blocked cell proliferation, migration and invasion were recovered by ULK1 overexpression. In vivo, circ_HIPK3 knockdown inhibited solid tumor growth.

Conclusion

Circ_HIPK3 knockdown blocked CCA malignant development partly via regulating the miR-148a-3p/ULK1 pathway.

Prognostic factors of resectable perihilar cholangiocarcinoma: a systematic review and meta-analysis of high-quality studies

Data on prognostic factors associated with outcome following resection of perihilar cholangiocarcinoma vary. We sought to define and characterize current available evidence on prognostic factors associated with perihilar cholangiocarcinoma after resection. The PubMed, Embase, and Cochrane library were systematically searched for relevant studies published before December 2019. Prognostic factors were identified from multivariate regression analyses in studies. Only high-quality studies were included (Newcastle-Ottawa Scale > 6 stars). A total of 45 studies involving 7338 patients were analyzed. The meta-analysis demonstrated that serum bilirubin levels (hazard ratio: 1.76, 95% confidence interval: 1.27-2.44), serum CA19-9 levels (hazard ratio: 1.32, 95% confidence interval: 1.05-1.65), tumor size (hazard ratio: 1.27, 95% confidence interval: 1.04-1.55), major vascular involvement (hazard ratio: 1.61, 95% confidence interval: 1.09-2.38), distance metastasis (hazard ratio: 17.60, 95% confidence interval: 2.01-154.09), perioperative blood transfusion (hazard ratio: 1.36, 95% confidence interval: 1.15-1.62), T-stage (hazard ratio: 1.96, 95% confidence interval: 1.47-2.61), lymph node metastasis (hazard ratio: 2.06, 1.83-2.31), resection margin status (hazard ratio: 2.34, 95% confidence interval: 1.89-2.89), not-well histology differentiation (hazard ratio: 2.03, 95% confidence interval: 1.69-2.44), perineural invasion (hazard ratio: 2.37, 95% confidence interval: 1.59-3.55), and lymphovascular invasion (hazard ratio: 1.41, 95% confidence interval: 1.15-1.73) were prognostic factors for poorer overall survival. Adjuvant chemotherapy (hazard ratio: 0.37, 95% confidence interval: 0.25-0.55) had a positive effect on prolonged overall survival. In addition, positive resection margin status (hazard ratio: 1.96, 95% confidence interval: 1.47-2.61) and lymph node metastasis (hazard ratio: 2.06, 95% confidence interval: 1.83-2.31) were associated with poorer disease-free survival. The prognostic factors identified in the present meta-analysis can be used to characterize patients in clinical practice and enrich prognostic tools, which could be included in future trial designs and generate hypotheses to be tested in future research to promote personalized treatment.

Repeated resection for recurrent intrahepatic cholangiocarcinoma: A retrospective German multicentre study

BACKGROUND

Tumour recurrence is common after resection of intrahepatic cholangiocarcinoma (ICC). Repeated resection is a potential curative treatment, but outcomes are not well-defined thus far. The aim of this retrospective multicentre cohort study was to show the feasibility and survival of repeated resection of ICC recurrence.

METHODS

Data were collected from 18 German hepato-pancreatico-biliary centres for patients who underwent repeated exploration of recurrent ICC between January 2008 and December 2017. Primary end points were overall (OS) and recurrence-free survival from the day of primary and repeated resection.

RESULTS

Of 156 patients who underwent repeated exploration for recurrent ICC, 113 underwent re-resection. CA19-9 prior to primary resection, R status of first liver resection and median time to recurrence were significant determinants of repeated resectability. Median OS in the repeated resection group was 65.2 months, with consecutive 1-, 3- and 5-year OS of 98%, 78% and 57% respectively. After re-exploration, median OS from primary resection was 46.7 months, with a consecutive 1-, 3- and 5-year OS of 95%, 55% and 22% respectively. From the day of repeated resection, the median OS was 36.8 months, with a consecutive 1-, 3- and 5-year OS of 86%, 51% and 34% respectively. Minor morbidity (grade I+II) was present in 27%, grade IIIa-IVb morbidity in 20% and mortality in 3.5% of patients.

CONCLUSION

Repeated resection of ICC has acceptable morbidity and mortality and seems to be associated with improved long-term survival. Structured follow-up after resection of ICC is necessary for early identification of these patients.

Nuclear Magnetic Resonance-Based Metabolomic Analysis of the Anticancer Effect of Metformin Treatment on Cholangiocarcinoma Cells

Metformin is a widely prescribed anti-diabetes drug with potential utilities for cancer therapies. Several studies have related metformin to the reduced risk of cholangiocarcinoma (CCA), highlighting its potentialities for the treatments of CCA. However, the underlying molecular mechanisms remain elusive. Here, we demonstrated that metformin treatment could inhibit proliferations of the human CCA cell lines Mz-ChA-1 and QBC939 in dose-dependent manners. The NMR-based metabonomic analyses showed distinct discriminations between the metformin-treated (Met) and control (Ctrl) groups of both CCA cells. Characteristic metabolites were identified by a combination of multivariate statistical analysis of 1D ¹H-NMR spectral data and the pair-wise t-test of metabolite levels. We then identified four significantly altered metabolic pathways based on the characteristic metabolites, including glucose metabolism, oxidative stress-related metabolism, energy metabolism, and amino acids metabolism. Comparing CCA cells with normal human umbilical vein endothelial cells (HUVECs), we found that metformin treatment profoundly promoted glycolysis and specifically increased the levels of BCAAs and UDP-GlcNAc, implying the occurrence of autophagy and cell cycle arrest in metformin-treated CAA cells. This work provides a mechanistic understanding of the anticancer effect of metformin treatment on CAA cells, and is beneficial to further developments of metformin as an anticancer drug.

Lipoproteins-Nanocarriers as a Promising Approach for Targeting Liver Cancer: Present Status and Application Prospects

The prevalence of liver cancer is increasing over the years and it is the fifth leading cause of mortality worldwide. The intrusive features and burden of low survival rate make it a global health issue in both developing and developed countries. The recommended chemotherapy drugs for patients in the intermediate and advanced stages of various liver cancers yield a low response rate due to the nonspecific nature of drug delivery, thus warranting the search for new therapeutic strategies and potential drug delivery carriers. There are several new drug delivery methods available to ferry the targeted molecules to the specific biological environment. In recent years, the nano assembly of lipoprotein moieties (lipidic nanoparticles) has emerged as a promising and efficiently tailored drug delivery system in liver cancer treatment. This increased precision of nano lipoproteins conjugates in chemotherapeutic targeting offers new avenues for the treatment of liver cancer with high specificity and efficiency. This present review is focused on concisely outlining the knowledge of liver cancer diagnosis, existing treatment strategies, lipoproteins, their preparation, mechanism and their potential application in the treatment of liver cancer.

Transcription factor HIF1α promotes proliferation, migration, and invasion of cholangiocarcinoma via long noncoding RNA H19/microRNA-612/Bcl-2 axis

Cholangiocarcinoma, which is the most common invasive malignant tumor of the biliary tract, has poor prognosis. There is evidence suggesting that hypoxia-inducible factor 1α (HIF1α) plays an important role in cholangiocarcinoma. Also, microRNA-612 (miR-612) is another key regulator of cholangiocarcinoma. In this study, we investigate the scantly documented interaction of HIF1α and miR-612 in cholangiocarcinoma. We first undertook microarray-based cholangiocarcinoma gene expression profiles to screen out the differentially expressed long noncoding RNAs (lncRNAs) and genes. We used reverse transcription quantitative polymerase chain reaction to detect the expression of HIF1α in normal bile duct and cholangiocarcinoma tissues, and in corresponding cells lines. Cell counting kit 8, scratch, and Transwell assays were used to detect the proliferation, migration and invasion of cholangiocarcinoma cells. Cell cycle distribution and apoptosis were detected by flow cytometry. ChIP, dual luciferase reporter gene assay, RNA pull-down, and RNA immunoprecipitation were used to verify relationship between HIF1α and lncRNA H19, and lncRNA H19 and miR-612. We also monitored tumor formation in nude mice to verify the effect of HIF1α on cholangiocarcinoma. HIF1α expression was elevated in cholangiocarcinoma tissues and cells. Silencing HIF1α reduced proliferation, migration, and invasion of cholangiocarcinoma cells. HIF1α transcriptionally activated the expression of lncRNA H19. Overexpression of miR-612 could rescue the proliferation, migration and invasion of cholangiocarcinoma cells caused by lncRNA H19 overexpression. Taken together, HIF1α activated lncRNA H19-mediated miR-612/Bcl-2 pathway to promote cholangiocarcinoma, suggesting a promising therapeutic target for cholangiocarcinoma.

Survival prediction for patients with non-resectable intrahepatic cholangiocarcinoma undergoing chemotherapy: a retrospective analysis comparing the tumor marker CA 19-9 with cross-sectional imaging

Purpose

Carbohydrate antigen (CA) 19-9 has been established as the main serum marker for patients with intrahepatic cholangiocarcinoma (ICC). The aim of this study was to compare the prognostic value of CA 19-9 changes versus response determined by imaging in patients with ICC undergoing chemotherapy.

Methods

Between 2003 and 2018, 151 patients with histopathologically confirmed ICC underwent chemotherapy at our tertiary care center for non-resectable or recurrent ICC, of whom 121 were included in this study. Serum CA 19-9 levels and imaging were retrospectively evaluated during chemotherapy. Log-rank testing and optimal stratification were used to classify patients into risk groups.

Results

Prior to chemotherapy, baseline serum CA 19-9 levels above the previously published cut-off of 37 U/ml were associated with poor survival (median OS 8.7 vs. 12.4 months, p = 0.003). After the beginning of chemotherapy, an increase in CA 19-9 of more than 40 U/ml resulted in impaired residual survival (median OS 5.0 vs. 12.1 months, p < 0.001). However, progressive disease at the first follow-up imaging proved the strongest predictor for poor outcome (median OS 4.6 vs. 15.5 months, p < 0.001). In contrast to prior studies, our data did not show statistically relevant differences in survival time with respect to absolute or relative decreases in serum CA 19-9 levels.

Conclusion

In our study, the disease control rate—that is, the absence of progressive disease—was the strongest predictor of prolonged residual OS. To this end, both CA 19-9 changes and progressive disease on initial follow-up showed remarkable discriminatory power, with the latter slightly outperforming the former. Therefore, imaging should remain the mainstay of patient evaluation during follow-up.

Electronic supplementary material

The online version of this article (10.1007/s00432-020-03200-2) contains supplementary material, which is available to authorized users.

Iodine‑131 metabolic radiotherapy leads to cell death and genomic alterations through NIS overexpression on cholangiocarcinoma

Cholangiocarcinoma (CC) is an aggressive liver tumor with limited therapeutic options. Natrium-iodide symporter (NIS) mediates the uptake of iodine by the thyroid, representing a key component in metabolic radiotherapy using iodine-131 (¹³¹I) for the treatment of thyroid cancer. NIS expression is increased in CC, providing the opportunity for a novel therapeutic approach for this type of tumor. Thus, in this study, we aimed to evaluate therapeutic efficacy of ¹³¹I in two human CC cell lines. Uptake experiments analyzed the ¹³¹I uptake profiles of the tumor cell lines under study. The cells were irradiated with various doses of ¹³¹I to evaluate and characterize the effects of metabolic radiotherapy. NIS protein expression was assessed by immunofluorescence methods. Cell survival was evaluated by clonogenic assay and flow cytometry was used to assess cell viability, and the type of death and alterations in the cell cycle. The genomic and epigenetic characterization of both CC cells was performed before and after irradiation. NIS gene expression was evaluated in the CC cells by RT-qPCR. The results revealed that CC cells had a higher expression of NIS. ¹³¹I induced a decrease in cell survival in a dose-dependent manner. With the increasing irradiation dose, a decrease in cell viability was observed, with a consequent increase in cell death by initial apoptosis. Karyotype and array comparative genomic hybridization (aCGH) analyses revealed that both CC cell lines were near-triploid with several numerical and structural chromosomal rearrangements. NIS gene expression was increased in the TFK-1 and HuCCT1 cells in a time-dependent manner. On the whole, the findings of this study demonstrate that the presence of NIS in cholangiocarcinoma cell lines is crucial for the decreased cell viability and survival observed following the exposure of cholangiocarcinoma cells to ¹³¹I.

Prognostic Value and Predication Model of Microvascular Invasion in Patients with Intrahepatic Cholangiocarcinoma

Background: Whether microvascular invasion (MVI) adversely influences oncological outcomes for intrahepatic cholangiocarcinoma (ICC) patients remains unclear. The purpose of this study was to determine the impact of MVI on postoperative survival and establish a new predictive model for MVI before surgical intervention in patients with ICC.

Methods: In this two-center retrospective study, 556 and 31 consecutive patients who underwent curative liver resection for ICC at ZSH and XJFH were analyzed, respectively. Propensity score matching (PSM) and Cox regression analyses were used to explore the prognostic role of MVI on the OS and DFS. Multivariate logistic regression was used to identify the relative risk factors of MVI, which were incorporated into the nomogram.

Results: After PSM, 50 MVI cases matched with 172 non-MVI cases, and no bias was observed between the two groups (propensity score, 0.118 (0.099, 0.203) vs. 0.115 (0.059, 0.174), p=0.251). The multivariate Cox analysis showed that MVI was negatively associated with OS (HR 1.635, 95% CI 1.405-1.993, p=0.04) and DFS (HR 1.596, 95% CI 1.077-2.366, p=0.02). The independent factors associated with MVI were ALT, AFP, tumor maximal diameter, and tumor capsule. The nomogram that incorporated these variables achieved good concordance indexes for predicting MVI. Patients with a cutoff score of 168 were considered to have different risks of the presence of MVI preoperatively.

Conclusions: The presence of MVI was an adverse prognostic factor for ICC patients. Using the nomogram model, the risk of an individual patient harboring MVI was determined, which led to a rational therapeutic choice.

Molecular Pathogenesis of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinomas are a heterogeneous group of malignancies arising from a number of cells of origin along the biliary tree. Although most cases in Western countries are sporadic, large population-based studies have identified a number of risk factors. This review summarises the evidence behind reported risk factors and current understanding of the molecular pathogenesis of cholangiocarcinoma, with a focus on inflammation and cholestasis as the driving forces in cholangiocarcinoma development.

RISK FACTORS FOR CHOLANGIOCARCINOGENESIS

Cholestatic liver diseases (e.g. primary sclerosing cholangitis and fibropolycystic liver diseases), liver cirrhosis, and biliary stone disease all increase the risk of cholangiocarcinoma. Certain bacterial, viral or parasitic infections such as hepatitis B and C and liver flukes also increase cholangiocarcinoma risk. Other risk factors include inflammatory disorders (such as inflammatory bowel disease and chronic pancreatitis), toxins (e.g. alcohol and tobacco), metabolic conditions (diabetes, obesity and non-alcoholic fatty liver disease) and a number of genetic disorders.

MOLECULAR PATHOGENESIS OF CHOLANGIOCARCINOMA

Regardless of aetiology, most risk factors cause chronic inflammation or cholestasis. Chronic inflammation leads to increased exposure of cholangiocytes to the inflammatory mediators interleukin-6, Tumour Necrosis Factor-ɑ, Cyclo-oxygenase-2 and Wnt, resulting in progressive mutations in tumour suppressor genes, proto-oncogenes and DNA mismatch-repair genes. Accumulating bile acids from cholestasis lead to reduced pH, increased apoptosis and activation of ERK1/2, Akt and NF-κB pathways that encourage cell proliferation, migration and survival. Other mediators upregulated in cholangiocarcinoma include Transforming Growth Factor-β, Vascular Endothelial Growth Factor, Hepatocyte Growth Factor and several microRNAs. Increased expression of the cell surface receptor c-Met, the glucose transporter GLUT-1 and the sodium iodide symporter lead to tumour growth, angiogenesis and cell migration. Stromal changes are also observed, resulting in alterations to the extracellular matrix composition and recruitment of fibroblasts and macrophages that create a microenvironment promoting cell survival, invasion and metastasis.

CONCLUSION

Regardless of aetiology, most risk factors for cholangiocarcinoma cause chronic inflammation and/or cholestasis, leading to the activation of common intracellular pathways that result in reactive cell proliferation, genetic/epigenetic mutations and cholangiocarcinogenesis. An understanding of the molecular pathogenesis of cholangiocarcinoma is vital when developing new diagnostic biomarkers and targeted therapies for this disease.

Implications of Intrahepatic Cholangiocarcinoma Etiology on Recurrence and Prognosis after Curative-Intent Resection: a Multi-Institutional Study

BACKGROUND

We sought to investigate the prognosis of patients following curative-intent surgery for intrahepatic cholangiocarcinoma (ICC) stratified by hepatitis B (HBV-ICC), hepatolithiasis (Stone-ICC), and no identifiable cause (conventional ICC) etiologic subtype.

METHODS

986 patients with HBV-ICC (n = 201), stone-ICC (n = 103), and conventional ICC (n = 682) who underwent curative-intent resection were identified from a multi-institutional database. Propensity score matching (PSM) was used to mitigate residual bias.

RESULTS

HBV-ICC patients more often had cirrhosis, earlier stage tumors, a mass-forming lesion, well-to-moderate tumor differentiation, and an R0 resection versus stone-ICC or conventional ICC patients. Five-year recurrence-free survival among HBV-ICC and conventional ICC patients was 23.9 and 17.8%, respectively, versus a recurrence-free of only 8.3% among patients with stone-ICC. Similarly, 5-year overall survival among patients with stone-ICC was only 18.3% compared with 48.9 and 38.0% for patients with HBV-ICC and conventional ICC, respectively. On PSM, patients with stone-ICC group had equivalent long-term outcomes as HBV-ICC patients. In contrast, on PSM, stone-ICC patients had a median overall survival of only 18.0 months versus 44.0 months for patients with conventional ICC. Median overall survival after intrahepatic-only recurrence among patients who had stone-ICC (6.0 months) was worse than OS among HBV-ICC (13.0 months) or conventional ICC (12.0 months) (p = 0.006 and p = 0.082, respectively).

CONCLUSIONS

While HBV-ICC had a better prognosis on unadjusted analyses, these differences were mitigated on PSM suggesting no stage-for-stage differences in outcomes compared with stone-ICC or conventional ICC. In contrast, patients with stone-ICC had worse long-term outcomes. These data highlight the relative importance of ICC etiology relative to established clinicopathological factors in the prognosis of patients with ICC.

Precision medicine in cholangiocarcinoma

Cholangiocarcinoma is one of the epithelial cancers with the poorest prognosis and the narrowest therapeutic choice in humans. Compared with other cancer types, cholangiocarcinoma has been often neglected by oncology and liver research studies, thereby leaving many issues unsolved. Apart from the early and marked aggressiveness, one of the main reasons of the still unsatisfying clinical management of cholangiocarcinoma is its wide tumor heterogeneity needing more than other diseases a 'precision medicine' approach. In this regard, in the last few years there has been an awakening of interest aimed at dissecting the complex molecular and genomic profile of cholangiocarcinoma. Thus, a range of molecular players have been recently identified as putative mechanistic determinants of cholangiocarcinoma invasiveness, encompassing tyrosine kinase receptors, metabolic enzymes, transcription factors, small GTPases, ubiquitin ligases, and chromatin-remodelling proteins, whose aberrant expression may derive from stochastic mutations as well as from pro-oncogenic paracrine signals released by the stromal microenvironment, which is particularly exuberant in cholangiocarcinoma. Herein, we sought to overview the most relevant observations unravelling the genomic landscape of cholangiocarcinoma, and the prognostic and predictive biomarkers that consequently have been emerging. Then, we will discuss innovative treatment approaches derived from conventional chemotherapy, targeted therapies, antiangiogenic therapies and immunotherapy, and how they are opening new avenues towards a precision medicine in cholangiocarcinoma.

18F-FDG PET/CT may be a suitable method for preoperative diagnosis and evaluation of Chinese older patients with hilar cholangiocarcinoma

Background

As the most common cholangiocarcinoma, hilar cholangiocarcinoma (HCCA) is a challenge in hepatobiliary surgery and causes a very poor prognosis. This study was designed to explore whether ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) may be a suitable method for preoperative diagnosis and evaluation of Chinese older patients with hilar cholangiocarcinoma.

Methods

This study enrolled 53 patients (≥ 65 years) with HCCA. ¹⁸F-FDG PET/CT scan was performed in all patients within one week before operation.

Results

¹⁸F-FDG PET/CT identified the tumors in all patients (100%). There were 48 patients (90.6%) with the same Bismuth-Corlette classifications determined by ¹⁸F-FDG PET/CT and operative pathology, whereas Bismuth-Corlette classifications of 5 patients (9.4%) were underestimated by ¹⁸F-FDG PET/CT compared with that determined by operative pathology. ¹⁸F-FDG PET/CT identified 19 patients (sensitivity: 67.9%) in 28 patients with lymph node metastases, and 22 patients (specificity: 88.0%) in 25 patients without lymph node metastases, with an accuracy of 77.4%. ¹⁸F-FDG PET/CT identified 8 patients (sensitivity: 47.1%) in 17 patients with liver, peritoneal or other distant metastases, and 35 patients (specificity: 97.2%) in 36 patients without liver, peritoneal or other distant metastases, with an accuracy of 81.1%. ¹⁸F-FDG PET/CT identified 17 patients (sensitivity: 73.9%) in 23 patients with unresectable tumors, and 24 patients (specificity: 80.0%) in 30 patients with resectable tumors, with an accuracy of 77.4%.

Conclusions

¹⁸F-FDG PET/CT may be a suitable method for preoperative diagnosis and evaluation, and offer valuable information for effective operation in Chinese older patients with HCCA.

Serum IL-6 and IL-8 Correlate with Prognostic Factors in Ovarian Cancer

The aim of the study was to correlate serum levels of IL-2, IL-5, IL-6, IL-8, IL-10, and TNF-α with clinical, laboratory, and pathological prognostic factors in patients with primary ovarian malignancy. Patients treated at the Pelvic Mass Ambulatory of the Discipline of Gynecology and Obstetrics/Oncology Research Institute (IPON) of the UFTM with confirmed diagnosis of malignant ovarian neoplasia (n = 26) were evaluated. Serum collection was performed preoperatively for the determination of tumor markers. The cytokines IL-2, IL-5, IL-6, IL-8, IL-10, and TNF-α were assayed by enzyme-linked immunosorbent assay (ELISA). The prognostic factors were compared using the Mann-Whitney test, with significance level lower than 0.05. When evaluating IL6, it was observed that higher serum levels were associated with overall survival less than 60 months (p = 0.0382). In the evaluation of IL8, higher serum levels were associated with neutrophil-to-lymphocyte ratio (NLR) ≥ 4 and platelet-to-lymphocyte ratio (PLR) ≥ 200 (p = 0.0198 and p = 0.0072, respectively), altered values of serum CA125 (p = 0.0457), and stage IIIC (p = 0.0486). Therefore, increased levels of IL-6 and IL-8 are associated with factors of worse prognosis in ovarian cancer. Additional studies with a larger sample of patients are needed to confirm the role of cytokines as prognostic factors, in the definition of treatment, and in the development of future target therapies.

Outcomes after vascular resection during curative-intent resection for hilar cholangiocarcinoma: a multi-institution study from the US extrahepatic biliary malignancy consortium

BACKGROUND

Surgical resection is the cornerstone of curative-intent therapy for patients with hilar cholangiocarcinoma (HC). The role of vascular resection (VR) in the treatment of HC in western centres is not well defined.

METHODS

Utilizing data from the U.S. Extrahepatic Biliary Malignancy Consortium, patients were grouped into those who underwent resection for HC based on VR status: no VR, portal vein resection (PVR), or hepatic artery resection (HAR). Perioperative and long-term survival outcomes were analyzed.

RESULTS

Between 1998 and 2015, 201 patients underwent resection for HC, of which 31 (15%) underwent VR: 19 patients (9%) underwent PVR alone and 12 patients (6%) underwent HAR either with (n = 2) or without PVR (n = 10). Patients selected for VR tended to be younger with higher stage disease. Rates of postoperative complications and 30-day mortality were similar when stratified by vascular resection status. On multivariate analysis, receipt of PVR or HAR did not significantly affect OS or RFS.

CONCLUSION

In a modern, multi-institutional cohort of patients undergoing curative-intent resection for HC, VR appears to be a safe procedure in a highly selected subset, although long-term survival outcomes appear equivalent. VR should be considered only in select patients based on tumor and patient characteristics.

The cholangiocyte primary cilium in health and disease

Cholangiocytes, like most cells, express primary cilia extending from their membranes. These organelles function as antennae which detect stimuli from bile and transmit the information into cells regulating several signaling pathways involved in secretion, proliferation and apoptosis. The ability of primary cilia to detect different signals is provided by ciliary associated proteins which are expressed in its membrane. Defects in the structure and/or function of these organelles lead to cholangiociliopathies that result in cholangiocyte hyperproliferation, altered fluid secretion and absorption. Since primary cilia dysfunction has been observed in several epithelial tumors, including cholangiocarcinoma (CCA), primary cilia have been proposed as tumor suppressor organelles. In addition, the loss of cilia is associated with dysregulation of several molecular pathways resulting in CCA development and progression. Thus, restoration of the primary cilia may be a potential therapeutic approach for several ciliopathies and CCA.

Molecular Mechanisms Driving Cholangiocarcinoma Invasiveness: An Overview

The acquisition of invasive functions by tumor cells is a first and crucial step toward the development of metastasis, which nowadays represents the main cause of cancer-related death. Cholangiocarcinoma (CCA), a primary liver cancer originating from the biliary epithelium, typically develops intrahepatic or lymph node metastases at early stages, thus preventing the majority of patients from undergoing curative treatments, consistent with their very poor prognosis. As in most carcinomas, CCA cells gradually adopt a motile, mesenchymal-like phenotype, enabling them to cross the basement membrane, detach from the primary tumor, and invade the surrounding stroma. Unfortunately, little is known about the molecular mechanisms that synergistically orchestrate this proinvasive phenotypic switch. Autocrine and paracrine signals (cyto/chemokines, growth factors, and morphogens) permeating the tumor microenvironment undoubtedly play a prominent role in this context. Moreover, a number of recently identified signaling systems are currently drawing attention as putative mechanistic determinants of CCA cell invasion. They encompass transcription factors, protein kinases and phosphatases, ubiquitin ligases, adaptor proteins, and miRNAs, whose aberrant expression may result from either stochastic mutations or the abnormal activation of upstream pro-oncogenic pathways. Herein we sought to summarize the most relevant molecules in this field and to discuss their mechanism of action and potential prognostic relevance in CCA. Hopefully, a deeper knowledge of the molecular determinants of CCA invasiveness will help to identify clinically useful biomarkers and novel druggable targets, with the ultimate goal to develop innovative approaches to the management of this devastating malignancy.

Circulating inflammatory proteins and gallbladder cancer: Potential for risk stratification to improve prioritization for cholecystectomy in high-risk regions

BACKGROUND

Inflammatory proteins could help identify individuals most likely to have gallbladder cancer (GBC) among those waiting for cholecystectomy.

METHODS

We analyzed 49 circulating inflammation-related proteins in 144 patients with GBC and 150 patients with gallstones. We calculated age- and sex-adjusted odds ratios (ORs) and 95% CIs for protein quantiles and GBC versus gallstones. Using proteins associated with early GBC (stage 1-2) that were selected in stepwise logistic regression, we created an inflammation score and explored the potential utility for risk stratification.

RESULTS

26 proteins (53%) had P values for the trend across categories ≤0.001, with associations for a one category increase ranging from 1.52 (95% CI: 1.20-1.94) for CC motif ligand 4 to 4.00 (95% CI: 2.76-5.79) for interleukin (IL)-8. Soluble tumor necrosis factor receptor 2 (sTNFR2), IL-6, sTNFR1, CC motif ligand 20 (CCL20), vascular cell adhesion molecule 1, IL-16, and granulocyte colony-stimulating factor had P values ≤0.001 for early GBC. Of those, IL-6, IL-16, CCL20, and STNFR1 were included in the inflammation score. In a high-risk setting with a pre-test disease risk of 10% (e.g., elderly patients) and using an inflammation score cutoff that provides 90% sensitivity, 39% of patients on the waiting list would be predicted to be positive, and 23% of those would be predicted to have GBC.

CONCLUSION

These results highlight the strong associations of inflammatory proteins with GBC risk and their potential clinical utility. Larger studies are needed to identify the most effective combinations of inflammatory proteins for detecting early GBC and precursor lesions.

Surgical Site Infection Is Associated with Tumor Recurrence in Patients with Extrahepatic Biliary Malignancies

BACKGROUND

Surgical site infections (SSI) are one of the most common complications after hepato-pancreato-biliary surgery. Infectious complications may lead to an associated immune-modulatory effect that inhibits the body's response to cancer surveillance. We sought to define the impact of SSI on long-term prognosis of patients undergoing surgical resection of extrahepatic biliary malignancies (EHBM).

METHODS

Patients undergoing surgery for EHBM between 2000 and 2014 were identified using a large, multi-center, national cohort dataset. Recurrence free survival (RFS) was calculated and a multivariable Cox proportional hazards model was utilized to identify potential risk factors for RFS including SSI.

RESULTS

Seven hundred twenty-eight patients included in the analytic cohort; 236 (32.4%) patients had perihilar cholangiocarcinoma, 241 (33.1%) gallbladder cancer, and 251 (34.5%) distal cholangiocarcinoma. A major resection, liver resection, was performed in 205 (28.3%) patients, while 110 (15.2%) patients had a pancreaticoduodenectomy. The overall incidence of morbidity was 55.8%; among the 397 patients who experienced a complication, 161 patients specifically had an SSI. The SSI occurred as an infection of the surgical site (n = 70, 9.6%) or formation of an abscess in the operative bed (n = 91, 12.5%). SSI was associated with long-term survival as patients who experienced an SSI had a median RFS of 19.5 months compared with 30.5 months for those patients who did not have an SSI (HR 1.40, 95% CI 1.08-1.80; p = 0.01). Among 279 patients who had EHBM that had no associated lymph node metastases, well-to-moderate tumor differentiation, as well as an R0 resection margin, SSI remained associated with worse RFS (HR 1.84, 95% CI 1.03-3.29; p = 0.038), as well as overall survival (HR 1.87, 95% CI 1.18-2.97; p = 0.008).

CONCLUSION

SSI was a relatively common occurrence following surgery for EHBM as 1 in 10 patients experienced an SSI. In addition to standard tumor-specific factors, the occurrence of postoperative SSI was adversely associated with long-term survival.

Survival after resection of perihilar cholangiocarcinoma in patients with lymph node metastases

BACKGROUND

The aim of this study was to compare patients with PHC with lymph node metastases (LN+) who underwent a resection with patients who did not undergo resection because of locally advanced disease at exploratory laparotomy.

METHODS

Consecutive LN+ patients who underwent a resection for PHC in 12 centers were compared with patients who did not undergo resection because of locally advanced disease at exploratory laparotomy in 2 centers.

RESULTS

In the resected cohort of 119 patients, the median overall survival (OS) was 19 months and the estimated 1-, 3- and 5-year OS was 69%, 27% and 13%, respectively. In the non-resected cohort of 113 patients, median OS was 12 months and the estimated 1-, 3- and 5-year OS was 49%, 7%, and 3%, respectively. OS was better in the resected LN+ cohort (p < 0.001). Positive resection margin (hazard ratio [HR]: 1.54; 95%CI: 0.97-2.45) and lymphovascular invasion (LVI) (HR: 1.71; 95%CI: 1.09-2.69) were independent poor prognostic factors in the resected cohort.

CONCLUSION

Patients with PHC who underwent a resection for LN+ disease had better OS than patients who did not undergo resection because of locally advanced disease at exploratory laparotomy. LN+ PHC does not preclude 5-year survival after resection.

Cullin 4A is associated with epithelial to mesenchymal transition and poor prognosis in perihilar cholangiocarcinoma

AIM

To explore the functional role of cullin 4A (CUL4A), a core subunit of E3 ubiquitin ligase, in perihilar cholangiocarcinoma (PHCC).

METHODS

The expression of CUL4A in PHCC cell lines was evaluated by Western blot and quantitative reverse transcription-polymerase chain reaction. Immunohistochemistry (IHC) was adopted to investigate the relationship between CUL4A expression and clinicopathological characteristics of PHCC. Univariate analysis and multivariate regression analysis were performed to analyze the risk factors related to overall survival (OS) and progression-free survival (PFS) of PHCC patients. Wound healing, Transwell and Matrigel assays were utilized to explore the function of CUL4A in PHCC metastasis. Furthermore, expression of epithelial to mesenchymal transition (EMT) markers was verified in cells with CUL4A knockdown or overexpression. The relationship between CUL4A expression and E-cadherin expression was also analyzed by IHC assay. Finally, the role of ZEB1 in regulating CUL4A mediated PHCC was detected by IHC, Western blot, Transwell and Matrigel assays.

RESULTS

CUL4A overexpression was detected in PHCC cell lines and clinical specimens. Clinicopathological analysis revealed a close correlation between CUL4A overexpression and tumour differentiation, T, N and TNM stages in PHCC. Kaplan-Meier analysis revealed that high CUL4A expression was correlated with poor OS and PFS of PHCC patients. Univariate analysis identified the following four parameters as risk factors related to OS rate of PHCC: T, N, TNM stages and high CUL4A expression; as well as three related to PFS: N stage, TNM stage and high CUL4A expression. Further multivariate logistic regression analysis identified high CUL4A expression as the only independent prognostic factor for PHCC. Moreover, CUL4A silencing in PHCC cell lines dramatically inhibited metastasis and the EMT. Conversely, CUL4A overexpression promoted these processes. Mechanistically, ZEB1 was discovered to regulate the function of CUL4A in promoting the EMT and metastasis.

CONCLUSION

CUL4A is an independent prognostic factor for PHCC, and it can promote the EMT by regulating ZEB1 expression. CUL4A may be a potential therapeutic target for PHCC.

Intrahepatic cholangiocarcinoma: current perspectives

Intrahepatic cholangiocarcinoma (ICC) is the second most common malignancy arising from the liver. ICC makes up about 10% of all cholangiocarcinomas. It arises from the peripheral bile ducts within the liver parenchyma, proximal to the secondary biliary radicals. Histologically, the majority of ICCs are adenocarcinomas. Only a minority of patients (15%) present with resectable disease, with a median survival of less than 3 years. Multidisciplinary management of ICC is complicated by large differences in disease course for individual patients both across and within tumor stages. Risk models and nomograms have been developed to more accurately predict survival of individual patients based on clinical parameters. Predictive risk factors are necessary to improve patient selection for systemic treatments. Molecular differences between tumors, such as in the epidermal growth factor receptor status, are promising, but their clinical applicability should be validated. For patients with locally advanced disease, several treatment strategies are being evaluated. Both hepatic arterial infusion chemotherapy with floxuridine and yttrium-90 embolization aim to downstage locally advanced ICC. Selected patients have resectable disease after downstaging, and other patients might benefit because of postponing widespread dissemination and biliary obstruction.