Cholangiocarcinoma: New Insights

Molecular Biomarkers in Cholangiocarcinoma: Focus on Bile

Hepatobiliary system cancers have demonstrated an increasing incidence rate in the past years. Without the presence of early symptoms, the majority of such cancers manifest with a set of similar symptoms, such as cholestasis resulting in posthepatic icterus. Differential diagnosis of hepatobiliary cancers is required for the therapy selection, however, the similarity of the symptoms complicates diagnostics. Thus, the search for molecular markers is of high interest for such patients. Cholangiocarcinoma (CCA) is characterized by a poor prognosis due to a low resectability rate, which occurs because this disease is frequently beyond the limits of surgical therapy at the time of diagnosis. The CCA is diagnosed by the combination of clinical/biochemical features, radiological methods, and non-specific serum tumor biomarkers, although invasive examination is still needed. The main disadvantage is limited specificity and sensitivity, which complicates early diagnostics. Therefore, prognostic and predictive biomarkers are still lacking and urgently needed for early diagnosis. In contrast to serum, bile is more accessible to identify biliary disease due to its simpler composition. Moreover, bile can contain higher concentrations of tumor biomarkers due to its direct contact with the tumor. It is known that the composition of the main bile component - bile acids, may vary during different diseases of the biliary tract. This review summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in serum and bile and provides an overview of the methods of bile acids analysis.

Prediction of regional lymph node metastasis in intrahepatic cholangiocarcinoma: it's not all about size

OBJECTIVES

Lymph node metastases (LNM) are frequent in patients with intrahepatic cholangiocarcinoma (iCC) and worsen their prognosis even after surgery. Our aim was to investigate the predictive value of lymph node (LN) short axis, the most common discriminator for identifying LNM in tumor-imaging and to develop a predictive model for regional LNM in iCC taking computed tomography (CT) features of extranodal disease into account.

MATERIALS AND METHODS

We enrolled 102 patients with pathologically proven iCC who underwent CT prior to hepatic resection and hilar lymph node dissection (LND) from 2005 to 2021. Two blinded radiologists assessed various imaging characteristics and LN diameters, which were analyzed by bivariate and multivariate logistic regression to develop a prediction model for LNM.

RESULTS

Prevalence of LNM was high (42.4 %) and estimated survival was shorter in LN-positive patients (p = 0.07). An LN short axis diameter of ≥ 9 mm demonstrated the highest predictive power for LNM. Three additional, statistically significant imaging features, presence of intrahepatic metastasis (p = 0.003), hilar tumor infiltration (p = 0.003), and tumor growth along the liver capsule (p = 0.004), were integrated into a prediction model, which substantially outperformed use of LN axis alone in ROC analysis (AUC 0.856 vs 0.701).

CONCLUSIONS

LN diameter alone proved to be a relevant but unreliable imaging-marker for LNM prediction in iCC. Our proposed prognostic model, which additionally considers intrahepatic metastases and hilar and capsular infiltration, significantly improves discriminatory power. Hilar and capsular involvement might indicate direct tumor extension to lymphatic liver structures.

An analysis of the correlation between the efficacy of training using a high-fidelity disease-specific simulator and the clinical outcomes of laparoscopic surgery for congenital biliary dilatation in pediatric patients

PURPOSE

The present study clarified the efficacy of repeating laparoscopic surgery training using a disease-specific simulator and investigated the clinical outcomes of laparoscopic surgery for congenital biliary dilatation (CBD) in pediatric patients after training.

METHODS

A high-fidelity laparoscopic hepaticojejunostomy simulator was used. Four pediatric surgeons performed practice laparoscopic hepaticojejunostomy three times using the simulator. The details of forceps manipulation during the task were analyzed. The clinical outcomes of 13 CBD cases treated with laparoscopic surgery in our institution were also evaluated based on medical records.

RESULTS

The time required to complete the task became significantly shorter each successive time (1st: 1062.18 ± 346.79 s vs. 3rd: 717.44 ± 260.80 s, p = 0.039). There were no significant differences in the total path length of the right forceps (1st: 55.56 ± 23.21 m vs. 3rd: 28.25 ± 17.01 m, p = 0.17), total path length of the left forceps (1st: 47.79 ± 20.79 m vs. 3rd: 31.83 ± 17.62 m, p = 0.17), average velocity of the right forceps (1st: 58.78 ± 21.29 mm/s vs.44.98 ± 10.25 mm/s, p = 0.47), or the average velocity of the left forceps (1st: 50.39 ± 19.25 mm/s vs. 52.26 ± 19.59 mm/s, p = 0.78). Regarding the clinical outcome, all CBD patients underwent laparoscopic surgery performed by practiced pediatric surgeons who had no experience. The operative time was 545.53 ± 91.01 min, and the blood loss was 24.2 ± 25.8 ml. There were no cases of open conversion, intraoperative adverse events, or anastomotic leakage.

CONCLUSION

Disease-specific simulator training significantly decreased the task performance time by improving the forceps manipulation economy. In addition, simulator training may improve the operative safety and quality of laparoscopic hepaticojejunostomy in pediatric CBD patients.

Autophagy activity in cholangiocarcinoma is associated with anatomical localization of the tumor

The presence of autophagy has been indicated in cholangiocarcinoma (CC), which disease has poor prognosis and limited treatment options. Recently, CC has been classified by anatomical localization as intrahepatic (iCC), perihilar (pCC) and distal (dCC), showing different clinical and molecular characteristics. Thus, our aim was to compare autophagy activity in CC samples resected from different anatomical locations. Further, we investigated whether autophagy could be modulated in cell lines originated from iCC and extrahepatic CC (eCC) following the treatments with autophagy inhibitory and inducing agents. Tissue microarrays were prepared from 70 CC (28 iCC, 19 pCC and 23 dCC), 31 adjacent non-tumorous and 9 hepatocellular carcinoma (HCC) samples. Autophagy markers LC3, p62 and Beclin1 as well as proliferation marker Ki-67 were monitored by immunohistochemistry and were associated with patients' survival. Modulation of autophagy was investigated in cell lines originated from iCC (HuH-28), eCC (TFK-1) and HCC (HepG2) by treating the cells with chloroquine (CQ) for inhibition and with Rapamycin, 5-Fluorouracil (5-FU) and Sorafenib for induction of autophagy. Our results indicated an inhibited autophagy in iCC and pCC tumor tissues, whereas active autophagy seemed to occur in dCC, especially in samples displaying low Ki-67 index. Additionally, low level of Beclin1 and high level of Ki-67 were associated with poor overall survival in dCC, suggesting the prognostic role of these proteins in dCC. Beside a baseline autophagy detected in each cell line, Rapamycin and 5-FU induced autophagy in iCC and HepG2 cell lines, Sorafenib in iCC cells. A chemotherapy agent in combination with CQ decreased IC50 effectively in the cell lines where basal and/or induced autophagy were present. In conclusion, we revealed differences in the autophagy activities of CC tissues and cell lines originated from different anatomical locations, which might influence patients' treatment. Our results also suggest a prognostic role of Beclin1 and Ki-67 in dCC.

Inhibition of Tumor Growth against Chemoresistant Cholangiocarcinoma by a Proapoptotic Peptide Targeting Interleukin-4 Receptor

Cholangiocarcinoma (CCA) has a poor prognosis and high chemoresistance. Interleukin-4 receptor (IL-4R) is overexpressed in several cancer cells and plays a crucial role in tumor progression and drug resistance. IL4RPep-1, an IL-4R-binding peptide, has been identified by phage display and used for tumor targeting. In this study, we exploited IL4RPep-1 to guide the tumor-specific delivery of a proapoptotic peptide to chemoresistant CCA, thereby inhibiting tumor growth. Immunohistochemistry of human primary CCA tissues showed that IL-4R levels were upregulated in moderately to poorly differentiated types, and higher levels of IL-4R are correlated with lower survival rates in patients with CCA. IL4RPep-1 was observed to preferentially bind with high IL-4R-expressing KKU-213 human CCA cells, whereas it barely bound with low IL-4R-expressing KKU-055 cells. A hybrid of IL4RPep-1 and a proapoptotic peptide (KLAKLAK)2 (named as IL4RPep-1-KLA) induced cytotoxicity and apoptosis in KKU-213 cells and increased those levels induced by 5-fluorouracil (5-FU). IL4RPep-1-KLA was internalized in the cells and colocalized with mitochondria. Whole-body fluorescence imaging and immunohistochemical analysis of tumor tissues showed the homing of IL4RPep-1-KLA as well as IL4RPep-1 to KKU-213 tumor in mice. Systemic administration of IL4RPep-1-KLA efficiently inhibited KKU-213 tumor growth, whereas treatment with 5-FU alone did not significantly inhibit tumor growth in mice. No significant systemic side effects including liver toxicity and immunotoxicity were observed in mice during peptide treatments. These findings suggest that IL4RPep-1-KLA holds potential as a targeted therapeutic agent against chemoresistant CCA.

Precursor Lesions of Cholangiocarcinoma: A Clinicopathologic Review

Cholangiocarcinoma (CCA) develops through multistep carcinogenesis. During the past decades, 2 precursors have been proved to evolve to CCA. The 2 main precursor lesions of CCA are biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct. It is an interesting and relatively novel entity for the hepatobiliary surgeons, radiologists, oncologists, and pathologists. It worth being familiar with these 2 entities for better communication between pathologists, oncologists, and surgeons to improve the treatment and follow-up of these lesions, which can definitely decrease their evolvement to CCA as an aggressive, poor prognostic, and life-threatening cancer. In this narrative review, I collected and discussed all published studies about these 2 precursor lesions of CCA including radiologic, clinical, and pathological manifestation.

Common transcriptional programs and the role of chemokine (C-C motif) ligand 20 (CCL20) in cell migration of cholangiocarcinoma

The incidence of cholangiocarcinoma (CCA) has risen in many countries, but there is still no appropriate screening and treatment available. The growing number of microarray data published todays can be a powerful resource for the discovery of biomarkers to tackle challenges in the management of CCA. This study analyzed multiple microarray datasets to identify the common transcriptional networks in CCA and select a possible biomarker for functional study in CCA cell lines. A systematic searching identified 4 microarray datasets from Gene Expression Omnibus (GEO) repository and PubMed articles. Differential expression analysis between tumor and normal tissues was performed in each dataset. In order to characterize the common expression pattern, differentially expressed genes (DEGs) from all datasets were combined and visualized by hierarchical clustering and heatmap. Gene enrichment analysis performed in each cluster revealed that over-expressed DEGs were enriched in cell cycle, cell migration and response to cytokines while under-expressed DEGs were enriched in metabolic processes such as oxidation-reduction, lipid, and drug. To explain tumor characteristics, genes enriched in cell migration and response to cytokines were further investigated. Among these genes, CCL20 was selected for functional study because its role has never been studied in CCA. Moreover, its signaling may be regulated by disrupting its only receptor, CCR6. Treatment with recombinant CCL20 induced higher cell migration and increased expression of N-cad. In contrast, knockdown of CCR6 by siRNA reduced cell migration ability and decreased N-cadherin level. Altogether, these results suggested the contribution of CCL20/CCR6 signaling in cell migration through epithelial-mesenchymal transition process. Thus, CCL20/CCR6 signaling might be a target for the management of CCA.

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.

Surgical Management of Intrahepatic Cholangiocarcinoma in Patients with Cirrhosis: Impact of Lymphadenectomy on Peri-Operative Outcomes

BACKGROUND

The consequences of lymphadenectomy (LND) on cirrhotic patients undergoing hepatectomy for intrahepatic cholangiocarcinoma (ICC) have not been investigated. We sought to analyze the impact of LND on morbidity among patients undergoing resection for ICC.

METHODS

A total of 1005 patients who underwent hepatectomy for ICC at one of the 14 participating institutions between 1990 and 2015 were identified. A propensity score match analysis was performed to reduce confounding biases between cirrhosis and non-cirrhosis groups.

RESULTS

Cirrhosis was diagnosed in 118 (11.7%) patients. Among non-cirrhotic patients, 63% underwent major liver resection versus only 20% among patients with cirrhosis (p < 0.001). LND was also less common among cirrhotic versus non-cirrhotic patients (19 vs. 50%, p < 0.001). The incidence of complications was 41 and 30% among patients who did not and did have cirrhosis, respectively (p = 0.022). The propensity-matched cohort included 150 patients. The incidence of complications was 71% among patients who underwent lymphadenectomy versus 23% among patients who did not undergo lymphadenectomy (OR 8.39) (p < 0.001). In the propensity-matched analysis, the median HLN was comparable among patients independent of cirrhosis status (median HLN: non-cirrhosis, 2.5 vs. cirrhosis, 2) (p = 0.95). While lymphadenectomy was associated with a higher risk of infections (non-cirrhosis, 0% vs. cirrhosis, 21%, p < 0.001) among patients with cirrhosis, infections were not associated with lymphadenectomy among non-cirrhotic patients (p = 0.19).

CONCLUSION

Lymphadenectomy was associated with an increased risk of complications among patients with cirrhosis undergoing surgery for ICC. The benefit of lymphadenectomy in cirrhotic patients should be considered in light of the higher risk of postoperative complications compared with non-cirrhotic patients.

Diagnostic value of contrast-enhanced ultrasound versus magnetic resonance imaging in extrahepatic cholangiocarcinoma

AIM

To compare the value of contrast-enhanced ultrasound and magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma (EHCC).

METHODS

Forty-six patients with extrahepatic cholangiocarcinoma (ECHH group) diagnosed at our hospital from January 2015 to December 2017 were enrolled. Forty-six patients with extrahepatic bile duct stones (CBDS group) and 46 patients with pancreatic head carcinomas or duodenum papilla disease (PD group) were also included. All patients underwent B-mode ultrasonography (BUS), CEUS, and MRI. Using the pathological diagnosis as the "gold standard", the receiver operating characteristic (ROC) curves were plotted to compare the diagnostic efficacy (including diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value) of the three examination methods for EHCC.

RESULTS

There was no significant difference between CEUS and MRI in the arterial phase (χ² = 1.105, P = 0.602). CEUS showed low enhancement in 86.96% and 100.00% of patients in the portal phase and delayed phase, respectively, which were significantly higher than those of MRI (13.04% and 13.04%, respectively; χ² = 50.261, 70.769; P = 0.000, 0.000). The ROC curve analysis showed that the area under the curve (AUC) of MRI and CEUS for the diagnosis of EHCC was higher that of BUS (0.924, 0.897 vs 0.690). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of BUS for EHCC were significantly lower than those of CEUS (χ² = 0.175, 0.066, 11.467, 37.260, 6.328; P = 0.000, 0.010, 0.001, 0.000, 0.012) and MRI (χ² = 0.227, 0.098, 13.378, 41.170, 9.082; P = 0.000, 0.002, 0.000, 0.000, 0.003). There was no significant difference in the diagnostic efficacy of CEUS and MRI for EHCC (χ² = 0.464, 0.383, 0.000, 0.001, 0.334; P = 0.496, 0.536, 1.000, 0.972, 0.563).

CONCLUSION

CEUS has high value in the diagnosis of EHCC and can be used as an important complement to MRI.