Targeted Therapies for Perihilar Cholangiocarcinoma

Perihilar cholangiocarcinoma (pCCA) is the anatomical sub-group of biliary tract cancer (BTC) arising between the second-order intrahepatic bile ducts and the cystic duct. Together with distal and intrahepatic cholangiocarcinoma (dCCA and iCCA; originating distal to, and proximal to this, respectively), gallbladder cancer (GBC) and ampulla of Vater carcinoma (AVC), these clinicopathologically and molecularly distinct entities comprise biliary tract cancer (BTC). Most pCCAs are unresectable at diagnosis, and for those with resectable disease, surgery is extensive, and recurrence is common. Therefore, the majority of patients with pCCA will require systemic treatment for advanced disease. The prognosis with cytotoxic chemotherapy remains poor, driving interest in therapies targeted to the molecular nature of a given patient's cancer. In recent years, the search for efficacious targeted therapies has been fuelled both by whole-genome and epigenomic studies, looking to uncover the molecular landscape of CCA, and by specifically testing for aberrations where established therapies exist in other indications. This review aims to provide a focus on the current molecular characterisation of pCCA, targeted therapies applicable to pCCA, and future directions in applying personalised medicine to this difficult-to-treat malignancy.

Recent Advances in the Mechanism Research and Clinical Treatment of Anti-Angiogenesis in Biliary Tract Cancer

Biliary tract cancers (BTCs), including cholangiocarcinoma (CCA) and gallbladder cancer (GC), are malignancies originating from the biliary tract with poor prognosis. In the early stage of BTCs, surgery is the only choice for cure. Unfortunately, most patients with BTC are diagnosed at an advanced stage and lose the opportunity for surgery. For many advanced solid tumors, antiangiogenic therapy has achieved encouraging results. While most clinical studies on antiangiogenic therapy in advanced BTCs have shown an excellent disease control rate (DCR), the improvement in overall survival (OS) is controversial. Understanding how the relevant signaling molecules influence the angiogenic response and the functional interaction is necessary for the formulation of new treatment regimens and the selection of enrolled patients. In this review, we aim to summarize and discuss the latest advances in antiangeogenesis for BTCs, mainly focusing on the molecular mechanism of angiogenesis in BTCs and the therapeutic effects from clinical trials. Furthermore, the horizon of antiangiogenesis for BTCs is highlighted.

Molecular Targets and Emerging Therapies for Advanced Gallbladder Cancer

Biliary tract cancers (BTCs), for their low incidence, have been often considered together. Gallbladder cancer (GBC) is the most common biliary tract malignancy, characterized by late diagnosis and poor prognosis, and although it is considered a rare tumor in western countries, other areas of the world show considerable incidence rates. In 2010, results from the large phase III ABC-02 clinical trial on GBC identified the gemcitabine and cisplatin combination as the most effective first-line regimen for both GBC and other BTCs. Since then, various systemic therapies have proven active in BTCs in both first- and second-line settings. Molecular profiling has highlighted important genetic differences between GBC and other BTCs, opening new ways for targeted therapy in advanced disease where standard chemotherapies show marginal benefit. Genome-wide data analysis have shown that GBC molecular landscape offer possible strategies for precision medicine approaches, and a better molecular understanding of the GBC is needed to better stratify patients for treatment. In this review, we discuss the molecular targetable agents for GBC, including the results that emerged by clinical trials exploring new treatment strategies.

New molecular and immunotherapeutic approaches in biliary cancer

Biliary tract carcinoma is a collective term for a group of rare gastrointestinal cancers. This overview outlines the key pathways and specialised therapeutics in biliary cancer and the emerging role of immunotherapy by highlighting the rationale and selected examples of studies in each area.

Correlations of survival with progression-free survival, response rate, and disease control rate in advanced biliary tract cancer: a meta-analysis of randomised trials of first-line chemotherapy

BACKGROUND

The need to promote novel drug development for advanced biliary tract cancer (ABTC) has emphasised the importance of determining whether various efficacy end points can act as surrogates for overall survival (OS).

METHODS

We conducted a literature search of randomised trials of first-line chemotherapy for ABTC and investigated correlations between efficacy end points and OS using weighted linear regression analysis. The ratios of the median OS, median progression-free survival (PFS), response rate, and disease control rate in each trial were used to summarise treatment effects. The surrogate threshold effect (STE), which was the minimum treatment effect on PFS required to predict a non-zero treatment effect on OS, was calculated.

RESULTS

Seventeen randomised trials with 36 treatment arms were identified, and a sample size of 2148 patients with 19 paired arms was analysed. The strongest correlation between all evaluated efficacy end points was observed between median OS and median PFS ratios (r(2)=0.66). In trials with gemcitabine-containing therapies and targeted agents, the r(2)-values were 0.78. The STE was estimated at 0.83 for all trials and 0.81 for trials with gemcitabine-containing therapies, and was not calculated for trials with targeted agents.

CONCLUSIONS

The median PFS ratio correlated well with the median OS ratio, and may be useful for planning a clinical trial for novel drug development.