Current and emerging immunotherapeutic approaches for biliary tract cancers

Background:Biliary tract cancers(BTCs)comprise a heterogeneous group of aggressive malignancies with unfavorable prognoses.The benefit of chemotherapy seems to have reached a bottleneck and,therefore,new effective therapeutic strategies for advanced BTCs are needed.Molecularly targeted therapies in selected patients are rapidly changing the situation.However,the low frequency of specific driver alterations in BTCs limits their wide application.Recently,immunotherapeutic approaches are also under active investigation in BTCs,but the role of immunotherapy in BTCs remains controversial.Data sources:Pub Med,Web of Science,and meeting resources were searched for relevant articles published from January 2017 to May 2022.The search aimed to identify current and emerging immunotherapeutic approaches for BTCs.Information on clinical trials was obtained from https://clinicaltrials.gov/and http://www.chictr.org.cn/.Results:Immunotherapy in BTC patients is currently under investigation,and most of the investigations focused on the application of immune checkpoint inhibitors(ICIs).However,only a subgroup of BTCs with microsatellite-instability high(MSI-H)/DNA mismatch repair-deficient(d MMR)or tumor mutational burden-high(TMB-H)benefit from monotherapy of ICIs,and limited activity was observed in the second or subsequent settings.Nevertheless,promising results come from studies of ICIs in combination with other therapeutic approaches,including chemotherapy,in advanced BTCs,with a moderate toxicity profile.Recent studies demonstrated that compared to GEMCIS alone,durvalumab plus GEMCIS significantly improved patient survival(TOPAZ-1 trial)and that ICIs-combined chemoimmunotherapy is poised to become a new frontline therapy option,regardless of TMB and MMR/MSI status.Adoptive cell therapy and peptide-or dendritic-based cancer vaccines are other immunotherapeutic options that are being studied in BTCs.Numerous biomarkers have been investigated to define their predictive role in response to ICIs,but no predictive biomarker has been validated,except MSI-H/dMMR.Conclusions:The role of immunotherapy in BTCs is currently under investigation and the results of ongoing studies are eagerly anticipated.Several studies have demonstrated the safety and efflcacy of ICIs in combination with chemotherapy in treatment-naive patients,such as the phaseⅢTOPAZ-1 trial,which will change the standard care of first-line chemotherapy for advanced BTCs.However,further research is needed to understand the best combination with immunotherapy and to discover more predictive biomarkers to guide clinical practice.

Distinct Immune Signatures in Peripheral Blood Predict Chemosensitivity in Intrahepatic Cholangiocarcinoma Patients

Intrahepatic cholangiocarcinoma(ICC)is the second most common liver cancer.Chemotherapy remains the main therapeutic strategy for advanced ICC patients,but chemosensitivity varies individually.Here,we applied cytometry by time-of-flight(CyTOF)to establish the immune profile of peripheral blood mononuclear cells(PBMCs)on the single-cell level at indicated time points before,during,and after chemotherapy.Multiplex immunofluorescence staining was applied to examine the spatial distribution of certain immune clusters.Tissue microarrays(TMAs)were used for prognostic evaluation.A total of 20 ICC patients treated with gemcitabine(GEM)were enrolled in our study,including eight cases with good response(R)and 12 cases with non-response(NR).Tremendous changes in PBMC composition,including an increased level of CD4/CD8 double-positive T cells(DPT),were observed after chemotherapy.Patients with higher level of CD4^(+)CD45RO^(+)CXCR3^(+)T cells before treatment had a favorable response to chemotherapy.Our study identified a positive correlation between the percentage of T cell subpopulations and clinical response after chemotherapy,which suggests that it is practical to predict the potential response before treatment by evaluating the proportions of the cell population in PBMCs.

Expert Consensus on Pathological Diagnosis of Intrahepatic Cholangiocarcinoma(2022 version)

Intrahepatic cholangiocarcinoma(iCCA)can originate from the large bile duct group(segment bile ducts and area bile ducts),small bile duct group(septal bile ducts and interlobular bile ducts),and terminal bile duct group(bile ductules and canals of Hering)of the intrahepatic biliary tree,which can be histopathological corresponding to large duct type iCCA,small duct type iCCA and iCCA with ductal plate malformation pattern,and cholangiolocarcinoma,respectively.The challenge in pathological diagnosis of above subtypes of iCCA falls in the distinction of cellular morphologies,tissue structures,growth patterns,invasive behaviors,immunophenotypes,molecular mutations,and surgical prognoses.For these reasons,this expert consensus provides nine recommendations as a reference for standardizing and refining the diagnosis of pathological subtypes of iCCA,mainly based on the 5th edition of the World Health Organization Classification of Tumours of the Digestive System.