Novel targeted therapy strategies for biliary tract cancers and hepatocellular carcinoma

A bibliometric analysis of indocyanine green (ICG) in hepatobiliary surgery from 2008 to 2021

Hundreds of scientific documents have reported on the application of indocyanine green (ICG) in hepatobiliary surgery in the past 13 years, but few bibliometric studies have been conducted. This study aimed to identify the situations of authors, countries/regions, institutions, journals, and hot topics in this field. The overall status and prospects of the current research in this field can be elucidated by bibliometric analysis. Publications from 2008 to 2021 were retrieved from the Web of Science (WoS) Core Collection. The search terms included "liver," "hepatic," "gallbladder," "bile duct," "surgery," "hepatectomy," "ICG," "indocyanine green," and related synonyms. The full records of the search results were exported in text, and the cooperation network and hot topics were evaluated and visualized using CiteSpace software. The number of publications increased between 2008 and 2021. A total of 1527 publications were included in the results, and the frequency of citations was 30,742. The largest proportion of the publications emanated from Japan, and the majority of the papers were published by Kokudo. Tian Jie contributed the largest number of papers in China. Research was relatively concentrated among one country/region. The latest hotspots, "preservation" and "resistance", frequently occurred. Cooperation between authors, countries, and institutions needs to be strengthened for high-quality research. Recent studies have focused on hepatectomy, bile duct resection, liver transplantation, and tumors in this field. Future research may focus on other aspects, such as liver preservation and resistance.

Epidemiologic patterns of biliary tract cancer in the United States: 2001–2015

Background

Biliary tract cancer (BTC) includes intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer (AVC). Although BTC is rare in the US, incidence is increasing and elevated in certain populations. This study examined BTC epidemiology in the US by age, sex, race/ethnicity, geographic region, and anatomic site.

Methods

BTC incidence, prevalence, mortality, and survival from 2001 to 2015 were evaluated using the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program and the Centers for Disease Control and Prevention’s National Program of Cancer Registries databases. Incidence and mortality rates were calculated and reported as age-standardized rates. Data were assessed by age, anatomic sites, geographic region, and race/ethnicity, and a joinpoint regression model was used to predict trends for age-adjusted BTC incidence and mortality rates.

Results

BTC incidence increased during the study period (annual percent change = 1.76, 95% confidence interval [1.59–1.92]), with the highest increase in ICC (6.65 [6.11–7.19]). Incidence of unspecified BTC initially increased but has recently begun to drop. Hispanic, Asian/Pacific Islander, Black, or American Indian/Alaska Native race/ethnicity was associated with higher BTC mortality rates than White race/ethnicity. Patients with ICC had the highest mortality rate (age-standardized rate = 1.87/100,000 person-years [1.85–1.88]). Five-year survival was 15.2% for all BTC, ranging from 8.5% (ICC) to 34.5% (AVC), and patients with distant disease at diagnosis had lower survival (3%) compared with those with regional (19.1%) or locally advanced disease (31.5%).

Conclusions

BTC incidence increased, survival was low across all subtypes, and mortality was greatest in patients with ICC. This underscores the serious, increasing unmet need among patients with BTC. Treatment options are limited, although clinical studies investigating immunotherapy, targeted therapies, and alternative chemotherapy combinations are ongoing. Epidemiological insights may improve patient care and inform the integration of novel therapies for BTC.

Placental growth factor promotes tumour desmoplasia and treatment resistance in intrahepatic cholangiocarcinoma

OBJECTIVE

Intrahepatic cholangiocarcinoma (ICC)-a rare liver malignancy with limited therapeutic options-is characterised by aggressive progression, desmoplasia and vascular abnormalities. The aim of this study was to determine the role of placental growth factor (PlGF) in ICC progression.

DESIGN

We evaluated the expression of PlGF in specimens from ICC patients and assessed the therapeutic effect of genetic or pharmacologic inhibition of PlGF in orthotopically grafted ICC mouse models. We evaluated the impact of PlGF stimulation or blockade in ICC cells and cancer-associated fibroblasts (CAFs) using in vitro 3-D coculture systems.

RESULTS

PlGF levels were elevated in human ICC stromal cells and circulating blood plasma and were associated with disease progression. Single-cell RNA sequencing showed that the major impact of PlGF blockade in mice was enrichment of quiescent CAFs, characterised by high gene transcription levels related to the Akt pathway, glycolysis and hypoxia signalling. PlGF blockade suppressed Akt phosphorylation and myofibroblast activation in ICC-derived CAFs. PlGF blockade also reduced desmoplasia and tissue stiffness, which resulted in reopening of collapsed tumour vessels and improved blood perfusion, while reducing ICC cell invasion. Moreover, PlGF blockade enhanced the efficacy of standard chemotherapy in mice-bearing ICC. Conclusion PlGF blockade leads to a reduction in intratumorous hypoxia and metastatic dissemination, enhanced chemotherapy sensitivity and increased survival in mice-bearing aggressive ICC.

Predictive biomarkers for systemic therapy of hepatocellular carcinoma

Introduction: Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the third cancer-related cause of death worldwide. In recent years, several systemic therapy drugs including sorafenib, lenvatinib, regorafenib, cabozantinib, ramucicurab, nivilumab, and pembrolizumab have been approved by FDA for advanced HCC. However, their insufficient efficacy, toxicity, and drug resistance require clinically applicable and validated predictive biomarkers.Areas covered: Our review covers the recent advancements in the identification of proteomic/genomic/epigenomic/transcriptomic biomarkers for predicting HCC treatment efficacy with the use of multi-kinase inhibitors (MKIs), CDK4/6 inhibitors, and immune checkpoint inhibitors (ICIs). Alpha-fetoprotein, des-carboxyprothrombin, vascular endothelial growth factor, angiopoietin-2, and dysregulated MTOR, VEGFR2, c-KIT, RAF1, PDGFRβ have the potential of proteomic/genomic biomarkers for sorafenib treatment. Alanine aminotransferase, aspartate aminotransferase, and albumin-bilirubin grade can predict the efficacy of other MKIs. Rb, p16, and Ki-67, and genes involved in cell cycle regulation, CDK1-4, CCND1, CDKN1A, and CDKN2A have been proposed for CD4/6 inhibitors, while dysregulated TERT, CTNNB1, TP53 FGF19, and TP53 are found to be predictors for ICI efficacy.Expert opinion: There are still limited clinically applicable and validated predictive biomarkers to identify HCC patients who benefit from systemic therapy. Further prospective biomarker validation studies for HCC personalized systemic therapy are required.

A case report of response to crizotinib in chemotherapy-refractory metastatic gallbladder cancer with met amplification and acquired resistance resulting from the loss of MET amplification

Gallbladder cancer (GBC) is a highly invasive disease and the most prevalent malignancy of the biliary system. Patients with GBC are commonly diagnosed at a late stage and have an unfavorable prognosis. Palliative chemotherapy has been the standard care for recurrent or metastatic disease in the past decades. Recently, several targeted therapies have been investigated in advanced biliary tract cancer (BTC) including inhibitors of genes or pathways such as FGFR2 fusions or rearrangements, IDH1 mutations, and NTRK gene fusions. Also, several clinical studies involving molecular stratification have been performed in defined patient groups, for example, BRAF V600E and HER2. Mesenchymal epithelial transition(MET)encodes a tyrosine kinase receptor and its ligand hepatocyte growth factor is a proto-oncogene. Targeting the MET signaling pathway is an effective strategy in numerous cancer types. However, the poor efficacy of MET inhibitors has been demonstrated in several phase II studies, but currently no reports have explained the potential mechanisms of resistance to MET inhibitors in BTC. In this article, we report a case of metastatic GBC with MET amplification that exhibited a rapid response to crizotinib after the failure of two lines of chemotherapy. After the patient had progressed and discontinued crizotinib, cabozantinib was introduced. Analysis of circulating tumor DNA (ctDNA) by next-generation sequencing (NGS) indicated a loss of MET amplification status. To our knowledge, this is the first case study demonstrating the use of NGS in ctDNA to monitor the development of acquired resistance during anti-MET treatment in GBC.

Conditional Cell Reprogramming in Modeling Digestive System Diseases

Digestive diseases have become an important source of morbidity and mortality. The considerable financial and health burdens caused by digestive diseases confirm the importance of extensive research to better understand and treat these diseases. The development of reliable preclinical models is essential for understanding the pathogenesis of digestive diseases and developing treatment and prevention methods. However, traditional established cell lines and animal models still have many limitations in the study of the digestive system. Conditional reprogramming (CR) cell culture is a newly developed primary technology that uses irradiated Swiss-3T3-J2 mouse fibroblast cells and the Rho-associated kinase (ROCK) inhibitor Y-27632 to rapidly and efficiently generate many cells from diseased and normal tissues. CR cells (CRCs) can be reprogrammed to maintain a highly proliferative state and recapitulate the histological and genomic features of the original tissue. Moreover, after removing these conditions, the phenotype was completely reversible. Therefore, CR technology may represent an ideal model to study digestive system diseases, to test drug sensitivity, to perform gene profile analysis, and to undertake xenograft research and regenerative medicine. Indeed, together with organoid cultures, CR technology has been recognized as one of the key new technologies by NIH precision oncology and also used for NCI human cancer model initiatives (HCMI) program with ATCC. In this article, we review studies that use CR technology to conduct research on diseases of the digestive system.

Percutaneous biliary stent with intraluminal brachytherapy versus palliative surgery in the management of extrahepatic cholangiocarcinoma

BACKGROUND

To compare the efficacy and outcomes of self-expandable metallic stent combined with catheter-loaded iodine-125 seeds (SEMS-CL-125I) brachytherapy versus conventional palliative surgery (PS) in advanced extrahepatic cholangiocarcinoma (EHCC).

METHODS

The retrospective analysis consisted of 101 advanced EHCC patients who received SEMS-CL-125I (n = 67) or underwent PS (n = 34). The clinical characteristics, postoperative complications and overall survival (OS) were compared between the two groups.

RESULTS

Serum levels of bilirubin, transaminase, and albumin (ALB) were significantly improved at 1 month, 3 months, and 6 months postoperatively in both groups (all P < 0.05). At 1 month after operation, the level of ALB in SEMS-CL-125I group was significantly higher than that in PS group (39.07 ± 3.83 vs. 36.60 ± 5.58 g/L, P = 0.015). No statistically significant difference was found in postoperative overall complications between the two groups (P = 0.052). Length of hospital stay was significantly shorter (P < 0.001), hospital costs were significantly less (P < 0.001), and OS was significantly better (P = 0.029) in SEMS-CL-125I group compared to PS group. Multivariate analysis further identified PS (HR = 2.90, 95% CI 1.71-4.93, P < 0.001) and higher level of carbohydrate antigen 19-9 (HR = 2.67, 95% CI 1.36-3.79, P = 0.002) as independent predictors of worse OS.

CONCLUSION

SEMS-CL-125I significantly improves outcomes compared with PS and could be a safe and effective treatment for advanced EHCC.

Characteristics of genomic alterations in Chinese cholangiocarcinoma patients

OBJECTIVE

Cholangiocarcinoma (CCA) is a primary malignancy, which is often diagnosed as advanced and inoperable due to the lack of effective biomarkers and poor sensitivity of clinical diagnosis. Here, we aimed to identify the genomic profile of CCA and provided molecular evidence for further biomarker development.

METHODS

The formalin-fixed paraffin-embedded and matching blood samples were sequenced by deep sequencing targeting 450 cancer genes and genomic alteration analysis was performed. Tumor mutational burden (TMB) was measured by an algorithm developed in-house. Correlation analysis was performed by Fisher's exact test.

RESULTS

The most commonly altered genes in this cohort were TP53 (41.27%, 26/63), KRAS (31.75%, 20/63), ARID1A and IDH1 (15.87%, 10/63, for both), SMAD4 (14.29%, 9/63), FGFR2 and BAP1 (12.70%, 8/63, for both), and CDKN2A (11.11%, 7/63). BAP1 mutations were significantly correlated with the CCA subtype. LRP2 mutations were significantly associated with the younger intrahepatic CCA (iCCA) patients, while BAP1 was associated with iCCA patients aged 55-65 years old. BAP1 and LRP2 mutations were associated with TMB.

CONCLUSIONS

Most Chinese CCA patients were 50-70 years old. BAP1 and LRP2 mutations were associated with the age of iCCA patients.

Development and validation of a novel immune-related prognostic model in hepatocellular carcinoma

Background

Growing evidence has suggested that immune-related genes play crucial roles in the development and progression of hepatocellular carcinoma (HCC). Nevertheless, the utility of immune-related genes for evaluating the prognosis of HCC patients are still lacking. The study aimed to explore gene signatures and prognostic values of immune-related genes in HCC.

Methods

We comprehensively integrated gene expression data acquired from 374 HCC and 50 normal tissues in The Cancer Genome Atlas (TCGA). Differentially expressed genes (DEGs) analysis and univariate Cox regression analysis were performed to identify DEGs that related to overall survival. An immune prognostic model was constructed using the Lasso and multivariate Cox regression analyses. Furthermore, Cox regression analysis was applied to identify independent prognostic factors in HCC. The correlation analysis between immune-related signature and immune cells infiltration were also investigated. Finally, the signature was validated in an external independent dataset.

Results

A total of 329 differentially expressed immune‐related genes were detected. 64 immune‐related genes were identified to be markedly related to overall survival in HCC patients using univariate Cox regression analysis. Then we established a TF-mediated network for exploring the regulatory mechanisms of these genes. Lasso and multivariate Cox regression analyses were applied to construct the immune-based prognostic model, which consisted of nine immune‐related genes. Further analysis indicated that this immune-related prognostic model could be an independent prognostic indicator after adjusting to other clinical factors. The relationships between the risk score model and immune cell infiltration suggested that the nine-gene signature could reflect the status of tumor immune microenvironment. The prognostic value of this nine-gene prognostic model was further successfully validated in an independent database.

Conclusions

Together, our study screened potential prognostic immune-related genes and established a novel immune-based prognostic model of HCC, which not only provides new potential prognostic biomarkers and therapeutic targets, but also deepens our understanding of tumor immune microenvironment status and lays a theoretical foundation for immunotherapy.

Somatic genetic aberrations in gallbladder cancer: comparison between Chinese and US patients

Background

Gallbladder cancer (GBC) is often diagnosed at an advanced stage with limited therapeutic options and poor prognosis. The five-year survival rate of this cancer when diagnosed at an advanced stage is below 5%, and the median survival time is less than a year with standard gemcitabine-based chemotherapy. Survival benefit with second-line treatment is unknown. Thus, there is an urgent need for novel treatment strategies and targeted therapy based on next generation sequencing (NGS) may be of value.

Methods

Comprehensive genomic profiling (CGP) was performed with NGS panel on paraffin-embedded tumors from a cohort of 108 Chinese and 107 US GBC patients. Clinical data were collected using an IRB approved protocol from a single-center in US and from China.

Results

In Chinese and US GBC cohorts, an average of 6.4 vs. 3.8 genomic alterations (GAs) were identified per patient. The most frequent alterations were TP53 (69.4%), CDKN2A/B (26%), ERBB2 (18.5%), PIK3CA (17%) and CCNE1 (13%) in Chinese cohort, TP53 (57.9%), CDKN2A/B (25%), SMAD4 (17%), ARID1A (14%), PIK3CA (14%) and ERBB2 (13.1%) in US patients. NFE2L2 mutations were present in 6.5% of Chinese patients and not observed in the US cohort. Interestingly, ERBB2 genetic aberrations were significantly associated with better pathological tumor differentiation and tended to co-occurrence with CDKN2A/B mutations in both the Chinese and US GBC cases. Out of the top 9 dysregulated genetic pathways in cancer, Chinese patients harbored more frequent mutations in ERBB genes (30.6% vs. 19.0%, P=0.04). High frequency of PI3K/mTOR pathway variations was observed in both Chinese (37%) and US cohort (33%) (P=0.5). Additionally, both Chinese and US GBC patients exhibited a relatively high tumor mutational burden (TMB) (17.6% and 17.0%, respectively). In the Chinese cohort, a significant association was seen between direct repair gene alterations and TMB ≥10 muts/Mb (P=0.004).

Conclusions

In our study, over 83% Chinese and 68% US GBC patients had actionable alterations that could potentially guide and influence personalized treatment options. The identification of high TMB, ERBB2, CDKN2A/B, PI3K/mTOR pathway and DNA repair mutations indicated that both Chinese and US GBC patients may benefit from targeted or immune checkpoint inhibitors.

KIFC1 promotes the proliferation of hepatocellular carcinoma in vitro and in vivo

Hepatocellular carcinoma (HCC) is a common type of malignant tumor worldwide with a high mortality rate. In the past 20 years, the morbidity rate of HCC has increased. Progress has been made in the clinical diagnosis and therapy for HCC. However, due to the high heterogeneity and metastasis targeted therapy for HCC exhibits great promise, and novel therapeutic targets for HCC are urgently required. Kinesin family member C1 (KIFC1) is a member of the kinesin superfamily of proteins. Previous studies have indicated a potential association between KIFC1 and cancer progression. However, the potential role of KIFC1 in the development of HCC remains unclear. The present study aimed to explore the function of KIFC1 in HCC. Immunohistochemical (IHC) assays were performed to explore the KIF15 expression levels in 74 samples of HCC and corresponding non-tumor tissues. The potential association between KIF15 expression levels and clinical features was analyzed, and the effects of KIF15 on cell proliferation of HCC were detected by colony formation and MTT assays. In addition, the proliferation-related proteins Ki67 and PCNA were detected by western blotting. The possible effects of KIF15 on tumor growth were measured in mice. The results demonstrated that a high expression level of KIFC1 was associated with poor prognosis of HCC. Further results indicated that KIFC1 promoted cell proliferation of HCC in vitro. In addition, knockdown of KIFC1 suppressed tumor formation and growth in mice. Therefore, these results provide a potential therapeutic target for the treatment of HCC.

Overexpression of miR-664 is associated with poor overall survival and accelerates cell proliferation, migration and invasion in hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. This study aimed to investigate the expression patterns of microRNA-664 (miR-664) in HCC tissues and cells, and assess its clinical significance and functional role in HCC.

Patients and methods

One hundred and thirty-four paired HCC and non-cancerous tissues were collected from patients who underwent surgery in Qianfoshan Hospital affiliated to Shandong University (Shandong, China) between 2009 and 2012. Expression of miR-664 was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Prognostic value of miR-664 in HCC was evaluated using Kaplan–Meier survival analysis and Cox regression analysis. Cell proliferation was analyzed using the CCK-8 assay, and cell migration and invasion of HCC cells was evaluated by the Transwell assay.

Results

Expression of miR-664 was significantly upregulated in HCC tissues and cells when compared with the normal controls (all P<0.05). MiR-664 expression was associated with lymph node metastasis, TNM stage and differentiation (all P<0.05) in the HCC patients. High miR-664 expression predicted poor overall survival (log-rank P=0.004) and acted as an independent prognostic factor (HR =1.945, 95% CI=1.078–3.508, P=0.027). According to cell experiments, the upregulation of miR-664 could promote, whereas the downregulation of miR-664 could inhibit proliferation, migration and invasion of HCC cells (all P<0.05). SIVA1 was predicted as a direct target gene of miR-664 in HCC.

Conclusion

All data indicated that overexpression of miR-664 is associated with poor prognosis of HCC patients, and may enhance tumor progression of HCC by targeting SIVA1. MiR-664 may be a candidate therapeutic target for HCC treatment.

Piperlongumine-Eluting Gastrointestinal Stent Using Reactive Oxygen Species-Sensitive Nanofiber Mats for Inhibition of Cholangiocarcinoma Cells

BACKGROUND

The aim of this study is to fabricate drug-eluting gastrointestinal (GI) stent using reactive oxygen species (ROS)-sensitive nanofiber mats for treatment of cholangiocarcinoma (CCA) cell. A ROS-producing agent, piperlongumine (PL)-incorporated nanofiber mats were investigated for drug-eluting stent (DES) application.

METHODS

Selenocystamine-conjugated methoxy poly(ethylene glycol) (MePEG) was conjugated with poly(L-lactide) (PLA) to produce block copolymer (LEse block copolymer). Various ratios of poly(ε-caprolactone) (PCL) and LEse block copolymer were dissolved in organic solvent with PL, and then nanofiber mats were fabricated by electro-spinning techniques.

RESULTS

The higher amount of LEse in the blend of PCL/LEse resulted in the formation of granules while PCL alone showed fine nanofiber structure. Nanofiber mats composed of PCL/LEse polymer blend showed ROS-sensitive drug release, i.e., PL release rate from nanofiber mats was accelerated in the presence of hydrogen peroxide (H₂O₂) while nanofiber mats of PCL alone have small changes in drug release rate, indicating that PL-incorporated nanofiber membranes have ROS responsiveness. PL itself and PL released from nanofiber mats showed almost similar anticancer activity against various CCA cells. Furthermore, PL released from nanofiber mats properly produced ROS generation and induced apoptosis of CCA cells as well as PL itself. In HuCC-T1 cell-bearing mice, PL-incorporated nanofiber mats showed improvement in anticancer activity.

CONCLUSION

PL-incorporated ROS-sensitive nanofiber mats were coated onto GI stent and showed improved anticancer activity with ROS responsiveness. We suggested PL-incorporated ROS-sensitive nanofiber mats as a promising candidate for local treatment of CCA cells.

Efficacy and safety of nivolumab for metastatic biliary tract cancer

Objective

PD-1 inhibitors have improved efficacy in many cancers. There are currently no reports of the use of PD-1 inhibitors, such as nivolumab, for metastatic biliary tract cancer (mBTC). This study reviewed the efficacy and safety of nivolumab for mBTC with the aim of exploring ways to improve efficacy and survival.

Methods

Thirty patients with mBTC were voluntarily treated with nivolumab at the PLA General Hospital. Nivolumab 3 mg/kg was administered. Progression-free survival (PFS) and overall survival were evaluated by Kaplan-Meier and univariate and multivariate analyses were carried out for clinical characteristics. Objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events (AEs) were also evaluated.

Results

The median treatment cycle is four cycles. One case was complete response, 5 cases partial response, 12 cases stable, and 12 cases progression. ORR was 20%, DCR was 60%, and PFS was 3.1 months (95% CI: 2.13-4.06). The AEs of nivolumab monotherapy were fatigue (three cases), fever (two cases), hypothyroidism (one case), skin reaction (one case), and liver injury (one case). Nivolumab combined with chemotherapy related grade 1-2 hematologic toxicity were leukopenia (five cases) and thrombocytopenia (two cases), and grade 3-4 were leukopenia (three cases). Non-hematologic toxicity grade 1-2 were nausea and vomiting (four cases), fatigue (four cases), fever (three cases), peripheral neurotoxicity (three cases), and hypothyroidism (one case). Univariate analysis showed that PFS of nivolumab combined with chemotherapy was statistically significant compared with that of nivolumab monotherapy (4.1 vs 2.3 months, P=0.031). Programmed death-ligand 1 (PD-L1) expression positively has no relationship with better PFS in contrast with PD-L1 negatively (3.6 vs 3.0 months P>0.05). Multivariate analysis show nivolumab combined with chemotherapy was only the independent factor for longer PFS (HR: 0.432, P<0.05).

Conclusion

The safety of nivolumab in mBTC is controllable. Further selection of superior populations is needed to improve the efficacy of nivolumab in mBTC.

Ampullary cancer: Evaluation of somatic and germline genetic alterations and association with clinical outcomes

BACKGROUND

Ampullary carcinoma (AC) is a rare gastrointestinal cancer. Pathogenic germline alterations (PGAs) in BRCA2 and potentially targetable somatic alterations (SAs) in ERBB2 and ELF3 have been previously described in AC. Memorial Sloan Kettering Cancer Center has implemented an opt-in strategy for germline testing (GT) and somatic testing (ST) for patients with AC to further evaluate the spectrum of PGAs and SAs.

METHODS

Forty-five patients with pathologically confirmed AC prospectively consented with the Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) test (410-468 genes). A subset of the cohort (23 of the 45 patients) also consented to GT with MSK-IMPACT (76-88 genes). Germline data for 21 of the remaining 22 patients who had not consented to GT were obtained in a de-identified fashion without clinical correlation. Clinicopathologic features, treatment histories, and survival data for consenting patients were collected and analyzed.

RESULTS

Pancreaticobiliary, intestinal, and mixed features of the 2 types were the primary pathologic subtypes of AC identified in this cohort. No difference in median overall survival was found between pathologic subtypes. Eight of 44 patients (18%) were identified as harboring pathogenic mutations in BRCA2, ATM, RAD50, and MUTYH. In addition, this study found a wide spectrum of SAs in genes such as KRAS, MDM2, ERBB2, ELF3, and PIK3CA. Two patients in the cohort underwent SA-targeted therapy, and 1 had a partial radiographic response.

CONCLUSIONS

Mutations in multiple somatic and germline genes were identified in this cohort. Significantly, actionable targets were identified in the tumors, and broader testing for PGAs and SAs should be considered for all patients with AC.

Regional differences in gallbladder cancer pathogenesis: Insights from a multi-institutional comparison of tumor mutations

BACKGROUND

Although rare in the United States, gallbladder cancer (GBCA) is a common cause of cancer death in some parts of the world. To investigate regional differences in pathogenesis and outcomes for GBCA, tumor mutations were analyzed from a sampling of specimens.

METHODS

Primary tumors from patients with GBCA who were treated in Chile, Japan, and the United States between 1999 and 2016 underwent targeted sequencing of known cancer-associated genes. Fisher exact and Kruskal-Wallis tests assessed differences in clinicopathologic and genetic factors. Kaplan-Meier methods evaluated differences in overall survival from the time of surgery between mutations.

RESULTS

A total of 81 patients were included. Japanese patients (11 patients) were older (median age, 72 years [range, 54-81 years]) compared with patients from Chile (21 patients; median age, 59 years [range, 32-73 years]) and the United States (49 patients; median age, 66 years [range, 46-87 years]) (P = .002) and had more well-differentiated tumors (46% vs 0% for Chile/United States; P < .001) and fewer gallstone-associated cancers (36% vs 67% for Chile and 69% for the United States; P = .13). Japanese patients had a median mutation burden of 6 (range, 1-23) compared with Chile (median mutation burden, 7 [range, 3-20]) and the United States (median mutation burden, 4 [range, 0-27]) (P = .006). Tumors from Japanese patients lacked AT-rich interaction domain 1A (ARID1A) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutations, whereas Chilean tumors lacked Erb-B2 receptor tyrosine kinase 3 (ERBB3) and AT-rich interaction domain 2 (ARID2) mutations. SMAD family member 4 (SMAD4) was found to be mutated similarly across centers (38% in Chile, 36% in Japan, and 27% in the United States; P = .68) and was univariately associated with worse overall survival (median, 10 months vs 25 months; P = .039). At least one potentially actionable gene was found to be altered in 80% of tumors.

CONCLUSIONS

Differences in clinicopathologic variables suggest the possibility of distinct GBCA pathogenesis in Japanese patients, which may be supported by differences in mutation pattern. Among all centers, SMAD4 mutations were detected in approximately one-third of patients and may represent a converging factor associated with worse survival. The majority of patients carried mutations in actionable gene targets, which may inform the design of future trials.

Novel targeted treatment options for advanced cholangiocarcinoma

INTRODUCTION

Surgical resection remains the mainstay of potentially curative treatment in the early stages of cholangiocarcinoma, whereas for the advanced stage, systemic chemotherapeutics and experimental targeted therapies are the primary treatment options. The molecular heterogeneity of the tumor is based on location, liver dysfunction, and relative rarity of the disease and confers challenges for clinical trial enrollment. The advancements in the understanding of molecular pathogenesis of cholangiocarcinoma have led to the development of targeted therapies that are currently being evaluated in the clinical trials.

AREAS COVERED

This review summarizes the current understanding and future directions of targeted therapeutic options in the management of advanced cholangiocarcinoma.

EXPERT OPINION

Advanced cholangiocarcinoma has a dismal prognosis; improved understanding of the molecular pathogenesis and advancements in development of targeted therapy offers hope that we may improve outcomes in this rare, but highly lethal cancer. Among the newly discovered molecular alterations, targeting FGFR2 fusions, IDH1/2 mutations and HER2 receptors hold great promise for improving the future management of cholangiocarcinoma. Immunotherapy in combination with targeted agents and chemotherapy may improve outcomes. In addition, drugs targeting the MEK, EGFR, KRAS, BRAF, and ROS1 pathways and neo-angiogenesis may also provide new horizons in the management of cholangiocarcinoma.