Impact of medical and surgical intervention on survival in patients with cholangiocarcinoma

Targeting cancer stem cells in cholangiocarcinoma (Review)

The incidence of cholangiocarcinoma has been increasing steadily over the past 50 years, but the survival rates remained low due to the disease being highly resistant to non-surgical treatment interventions. Cancer stem cell markers are expressed in cholangiocarcinoma, suggesting that they serve a significant role in the physiology of the disease. Cancer stem cells are frequently implicated in tumor relapse and acquired resistance to a number of therapeutic strategies, including chemotherapy, radiation and immune checkpoint inhibitors. Novel targeted therapies to eradicate cancer stem cells may assist in overcoming treatment resistance in cholangiocarcinoma and reduce the rates of relapse and recurrence. Several signaling pathways have been previously documented to regulate the development and survival of cancer stem cells, including Notch, janus kinase/STAT, Hippo/yes-associated protein 1 (YAP1), Wnt and Hedgehog signaling. Although pharmacological agents have been developed to target these pathways, only modest effects were reported in clinical trials. The Hippo/YAP1 signaling pathway has come to the forefront in the field of cancer stem cell research due to its reported involvement in epithelium-mesenchymal transition, cell adhesion, organogenesis and tumorigenesis. In the present article, recent findings in terms of cancer stem cell research in cholangiocarcinoma were reviewed, where the potential therapeutic targeting of cancer stem cells in this disease was discussed.

Diagnosis and Management of Intrahepatic and Extrahepatic Cholangiocarcinoma

Cholangiocarcinomas (CC) are rare tumors which usually present late and are often difficult to diagnose and treat. CCs are categorized as intrahepatic, hilar, or extrahepatic. Epidemiologic studies suggest that the incidence of intrahepatic CCs may be increasing worldwide. In this chapter, we review the risk factors, clinical presentation, and management of cholangiocarcinoma.

JQ1 Induces DNA Damage and Apoptosis, and Inhibits Tumor Growth in a Patient-Derived Xenograft Model of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a fatal disease with a 5-year survival of <30%. For a majority of patients, chemotherapy is the only therapeutic option, and virtually all patients relapse. Gemcitabine is the first-line agent for treatment of CCA. Patients treated with gemcitabine monotherapy survive ∼8 months. Combining this agent with cisplatin increases survival by ∼3 months, but neither regimen produces durable remissions. The molecular etiology of this disease is poorly understood. To facilitate molecular characterization and development of effective therapies for CCA, we established a panel of patient-derived xenograft (PDX) models of CCA. We used two of these models to investigate the antitumor efficacy and mechanism of action of the bromodomain inhibitor JQ1, an agent that has not been evaluated for the treatment of CCA. The data show that JQ1 suppressed the growth of the CCA PDX model CCA2 and demonstrate that growth suppression was concomitant with inhibition of c-Myc protein expression. A second model (CCA1) was JQ1-insensitive, with tumor progression and c-Myc expression unaffected by exposure to this agent. Also selective to CCA2 tumors, JQ1 induced DNA damage and apoptosis and downregulated multiple c-Myc transcriptional targets that regulate cell-cycle progression and DNA repair. These findings suggest that c-Myc inhibition and several of its transcriptional targets may contribute to the mechanism of action of JQ1 in this tumor type. We conclude that BET inhibitors such as JQ1 warrant further investigation for the treatment of CCA. Mol Cancer Ther; 17(1); 107-18. ©2017 AACR.

Evaluating a preoperative protocol that includes magnetic resonance imaging for lymph node metastasis in the Cholangiocarcinoma Screening and Care Program (CASCAP) in Thailand

BACKGROUND

Treatment planning especially liver resection in cholangiocarcinoma (CCA) depends on the extension of tumor and lymph node metastasis which is included as a key criterion for operability. Magnetic resonance imaging (MRI) offers a rapid and powerful tool for the detection of lymph node metastasis (LNM) and in the current manuscript is assessed as a critical tool in the preoperative protocol for liver resection for treatment of CCA. However, the accuracy of MRI to detect LNM from CCA had yet to be comprehensively evaluated.

METHODS

The accuracy of MRI to detect LNM was assessed in a cohort of individuals with CCA from the Cholangiocarcinoma Screening and Care Program (CASCAP), a screening program designed to reduce CCA in Northeastern Thailand by community-based ultrasound (US) for CCA. CCA-positive individuals are referred to one of the nine tertiary centers in the study to undergo a preoperative protocol that included enhanced imaging by MRI. Additionally, these individuals also underwent lymph node biopsies for histological confirmation of LNM (the "gold standard") to determine the accuracy of the MRI results.

RESULTS

MRI accurately detected the presence or absence of LNM in only 29 out of the 51 CCA cases (56.9%, 95% CI 42.2-70.7), resulting in a sensitivity of 57.1% (95% CI 34.0-78.2) and specificity of 56.7% (95% CI 37.4-74.5), with positive and negative predictive values of 48.0% (95% CI 27.8-68.7) and 65.4% (95% CI 44.3-82.8), respectively. The positive likelihood ratio was 1.32 (95% CI 0.76-2.29), and the negative likelihood ratio was 0.76 (95% CI 0.42-1.36).

CONCLUSIONS

MRI showed limited sensitivity and a poor positive predictive value for the diagnosis of LNM for CCA, which is of particular concern in this resource-limited setting, where simpler detection methods could be utilized that are more cost-effective in this region of Thailand. Therefore, the inclusion of MRI, a costly imaging method, should be reconsidered as part of protocol for treatment planning of CCA, given the number of false positives, especially as it is critical in determining the operability for CCA subjects.

Association between cellular radiosensitivity and G1/G2 checkpoint proficiencies in human cholangiocarcinoma cell lines

Cholangiocarcinoma is a destructive malignancy with a poor prognosis and lack of effective medical treatment. Radiotherapy is an alternative treatment for patients with unresectable cholangiocarcinoma. However, there are limited data on the radiation responsiveness of individual cholangiocarcinoma cells, which is a key factor that influences radiation treatment outcome. In this study, we found that cholangiocarcinoma cell lines differ remarkably in their radiosensitivity. The variation of radiosensitivity of cholangiocarcinoma cells correlates with their p53 status and existing G1 and/or G2 checkpoint defects. We also demonstrated the potential of checkpoint kinase Chk1/2 inhibition on the enhancement of the radiosensitivity of cholangiocarcinoma cells. Thus, this study provides useful information for predicting radiation response and provides evidence for the enchantment of radiotherapeutic efficiency by targeting checkpoint kinase Chk1/2 in some subpopulations of cholangiocarcinoma patients.

Identification of risk and prognostic factors for patients with clonorchiasis-associated intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma caused by clonorchiasis (CICC) has a poor prognosis, and there have been insufficient studies regarding risk and prognostic factors. We aimed to identify CICC-associated factors.

METHODS

A retrospective analysis of 127 eligible patients with CICC was performed with 254 clonorchiasis cases used as matched controls to identify risk factors for CICC. The main outcomes analyzed included overall survival (OS) and disease-free survival (DFS).

RESULTS

Out of 127 surgeries, R0 resection was performed in 61 patients, R1 in 32 patients, and R2 in 22 patients; nonresection surgery was performed in 12 patients. Median OS for the entire cohort was 29.5 months. Median OS and DFS for 61 patients with R0 resection were 52.4 months and 41.5 months, respectively. We found independent risk factors for CICC were duration of raw fish consumption of ≥28 years (p < 0.001) and hepatitis B virus infection (p = 0.040). R0 resection (p < 0.001), well or moderately differentiated tumor (p = 0.019), and stage I to II tumor (p < 0.001) predicted improved OS for CICC. Serum carcinoembryonic antigen level of ≤5 ng/ml (p = 0.029) and stage I to II tumor (p < 0.001) predicted improved DFS.

CONCLUSIONS

Duration of raw fish consumption ≥28 years and hepatitis B virus infection were significant risk factors for CICC in patients with clonorchiasis. For patients with CICC, curative resection is an effective treatment. Higher tumor differentiation and earlier American Joint Committee on Cancer stage predicted good prognosis. Serum carcinoembryonic antigen level was found to predict the possibility of recurrence after curative resection.

Temporal trends in liver-directed therapy of patients with intrahepatic cholangiocarcinoma in the United States: a population-based analysis

BACKGROUND AND OBJECTIVES

Data on outcomes after liver-directed therapy for intrahepatic cholangiocarcinoma (ICC) are limited due to the rarity of the disease. We sought to define overall utilization and temporal trends of liver-directed therapy for ICC.

METHODS

We identified 5,388 patients with ICC using the Surveillance Epidemiology and End Results (SEER) database between 1983 and 2010. Patients were characterized based on the type of liver-directed therapy received: surgical resection, ablation therapy, and radiation therapy.

RESULTS

The majority of patients did not undergo liver-directed therapy (n = 4,156, 77.1%). Among those undergoing liver-directed therapy, surgical resection was most commonly performed (n = 672, 54.5%) and its utilization increased threefold over time (P = 0.001). The use of ablation therapy alone was used in 5.2% of patients and increased nearly sixfold over time (P = 0.39) whereas the use of radiation therapy alone decreased by nearly half (P < 0.001). Overall median survival was 10 months. Poor predictors of survival include tumor-based factors such as regional and distant disease, as well as poorly differentiated and large tumors (>5 cm).

CONCLUSION

There was a moderate improvement in overall survival in patients with ICC between 1983 and 2010. The majority of patients with ICC are not undergoing liver-directed therapy. Among those who do undergo liver-directed therapy, the use of ablation therapy and surgery are increasing with nearly three in five patients undergoing resection.