iCCA Patients Research Articles

Abstract PR06: Identifying regulatory transcription factors in primary liver cancer cell lineage commitment using single cell ATAC sequencing

Abstract Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) are the two main types of primary liver cancer (PLC), a leading cause of cancer related mortality. The key mechanisms of transcription regulation that delineates a cell of origin to either HCC or iCCA remain underexplored. We hypothesize that chromatin accessibility patterns reflect transcriptional regulatory circuitry that controls PLC lineage development. We aim to trace developmental lineages of cells that compose tumors using single cell chromatin accessibility data. Single cell Assay for Transposase-Accessible Chromatin (ATAC) and RNA sequencing was done on biopsies collected from 16 patients, including 13 patients with HCC and 3 patients with iCCA tumors enrolled for interventional studies at the NIH Clinical Center. ATAC and RNA sequencing libraries were made using the 10X Genomics Chromium platform. Downstream analysis includes graph-based clustering, UMAP embedding, and cell type label transfer using Seurat v3.0. Transcription factor (TF) activity estimation was done using ChromVAR. In total, we collected high quality chromatin accessibility data from 18,609 cells and gene expression data from 32,127 cells. Using the gene expression data, we transferred malignant and non-malignant cell type labels to our chromatin accessibility data. Clustering based on the most variably accessible chromatin peaks successfully separated cells by cell type identity. Strikingly, further clustering of malignant cells alone using the most variable TF activity scores separated cells into clusters based on tumor type, suggesting variation in TF activity was driven by differences between HCC and iCCA tumors. Comparing TF activity between HCC and iCCA, we discovered 31 significant differentially activated TFs between the 2 lineages (FDR<0.1). Gene set enrichment analysis revealed these 31 TFs fell into distinct families that regulate cell proliferation and differentiation. To further explore the role of these TFs in PLC, we utilized bulk transcriptome data collected from the TIGER-LC cohort, including samples from 62 HCC and 91 iCCA patients. Hierarchical clustering of the TIGER-LC cohort based on expression of the identified 31 TFs separated patients into 2 main clusters, 1 dominantly HCC and 1 dominantly iCCA. Several TFs strongly enriched in either HCC or iCCA showed mutual exclusivity in expression. To investigate the interplay between the microenvironment and activation of lineage associated TFs, we characterized the non-malignant cells for which we collected single cell chromatin accessibility data. Our data suggests proportions of certain T-cell and myeloid cell subtypes may be different between HCC and iCCA. We are further exploring transcriptional regulatory circuity of paracrine signaling between the surrounding microenvironment and malignant cells in the role of PLC lineage commitment. In conclusion, we hypothesize that activation of these TFs with interplay of the microenvironment may drive and sustain lineage commitment between HCC and iCCA tumors. Citation Format: Amanda J Craig, Lichun Ma, Sophia Heinrich, Michael Kelly, Tim Greten, Xin Wei Wang. Identifying regulatory transcription factors in primary liver cancer cell lineage commitment using single cell ATAC sequencing [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr PR06.

Molecular Profile and Prognostic Value of BAP1 Mutations in Intrahepatic Cholangiocarcinoma: A Genomic Database Analysis.

Background. Recent years have witnessed the advent of molecular profiling for intrahepatic cholangiocarcinoma (iCCA), and new techniques have led to the identification of several molecular alterations. Precision oncology approaches have been widely evaluated and are currently under assessment, as shown by the recent development of a wide range of agents targeting Fibroblast Growth Factor Receptor (FGFR) 2, Isocitrate Dehydrogenase 1 (IDH-1), and BRAF. However, several knowledge gaps persist in the understanding of the genomic landscape of this hepatobiliary malignancy. Methods. In the current study, we aimed to comprehensively analyze clinicopathological features of BAP1-mutated iCCA patients in public datasets to increase the current knowledge on the molecular and biological profile of iCCA. Results. The current database study, including 772 iCCAs, identified BAP1 mutations in 120 cases (15.7%). According to our analysis, no differences in terms of overall survival and relapse-free survival were observed between BAP1-mutated and BAP1 wild-type patients receiving radical surgery. In addition, IDH1, PBRM1, and ARID1A mutations were the most commonly co-altered genes in BAP1-mutated iCCAs. Conclusions. The genomic characterization of iCCA is destined to become increasingly important, and more efforts aimed to implement iCCA genomics analysis are warranted.

Platinum sensitivity in patients with IDH1/2 mutated vs wild-type intrahepatic cholangiocarcinoma: A propensity score-based study.

Isocitrate dehydrogenase (IDH)1/2 mutations are the most frequent druggable alterations in intrahepatic cholangiocarcinoma (iCCA), reported in ~20% of cases. Preclinical evidence indicates that these mutations are associated with homologous recombination deficiency (HRD), which could be exploited as a target for platinum chemotherapy (ChT) and PARP inhibitors. However, the role of IDH1/2 mutations as surrogate biomarkers for platinum efficacy is unknown. We conducted a multicenter, propensity score-matched analysis to investigate the impact of IDH1/2 mutations on progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR) in patients with iCCA treated with platinum-based ChT. An exploratory comparison of complex HRD estimates between IDH1/2 mutated and wild-type tumors from TCGA was also performed. A total of 120 cases were matched in a 1:1 ratio (60 IDH1/2 mutant and 60 wild-type). No differences were observed for platinum-based PFS (7.7 vs 7.3months, P=.970), DCR (66.1% vs 74.1%, P=.361) and ORR (27.8% vs 25.0%, P=.741). IDH1/2 mutations showed mutual exclusivity with genomic alterations in ATM, BRCA2, MST1R, NF1, FGFR2 and CDKN2A/B losses, respectively, with no clear survival and response differences. Among TCGA tumors, IDH1/2 mutated CCA did not show higher HRD compared to wild-type cases. IDH1/2 mutations are not associated with increased sensitivity to platinum-based ChT in iCCA patients. Deeper genomic sequencing is needed to elucidate the HRD phenotype in IDH1/2 mutant iCCA and exploit its therapeutic vulnerabilities.

Efficacy and Safety of Drug-Eluting Beads Transarterial Chemoembolization Combining Immune Checkpoint Inhibitors in Unresectable Intrahepatic Cholangiocarcinoma: A Propensity Score Matching Analysis.

PurposeTo assess the effectiveness and safety of drug-eluting beads transarterial chemoembolization plus immune checkpoint inhibitors (DEB-TACE+ICIs) versus chemotherapy (gemcitabine+cisplatin) for patients with unresectable intrahepatic cholangiocarcinoma (iCCA).Materials and MethodsThis retrospective study included unresectable iCCA patients treated with DEB-TACE+ICIs or chemotherapy between May, 2019 and August, 2021. The differences in tumor responses, progression-free survival (PFS), overall survival (OS), and treatment-related adverse events (TRAEs) were compared between the 2 groups. Patient baseline characteristics, PFS, and OS were compared among 2 groups before and after propensity score-matching (PSM). Factors affecting PFS and OS were analyzed by Cox’s proportional hazards regression model.ResultsThe study included 49 patients with unresectable iCCA patients, 20 in the DEB-TACE+ICIs group and 29 in the chemotherapy group. PSM analysis created 20 pairs of patients in 2 groups. The patients in the DEB-TACE+ICIs group had a higher objective response rate (55.0% vs. 20.0%, P=0.022), higher PFS (median, 7.2 vs. 5.7 months, P=0.036), and higher OS (median, 13.2 vs. 7.6 months, P=0.015) than those in the chemotherapy group. Multivariate analyses suggested that chemotherapy, tumor size >5cm, and multiple tumors were the independent risk factors for PFS and OS. The incidence of TRAEs was similar between the 2 groups.ConclusionCompared to chemotherapy, DEB-TACE plus ICIs improved survival and was well-tolerated in patients with unresectable iCCA.

Outcome of liver cancer patients with SARS-CoV-2 infection: An International, Multicentre, Cohort Study.

Background & AimsInformation about the impact of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in patients with liver cancer is lacking. This study characterizes the outcomes and mortality risk in this population.MethodsMulticentre retrospective, cross‐sectional, international study of liver cancer patients with SARS‐CoV‐2 infection registered between February and December 2020. Clinical data at SARS‐CoV‐2 diagnosis and outcomes were registered.ResultsTwo hundred fifty patients from 38 centres were included, 218 with hepatocellular carcinoma (HCC) and 32 with intrahepatic cholangiocarcinoma (iCCA). The median age was 66.5 and 64.5 years, and 84.9% and 21.9% had cirrhosis in the HCC and iCCA cohorts respectively. Patients had advanced cancer stage at SARS‐CoV‐2 diagnosis in 39.0% of the HCC and 71.9% of the iCCA patients. After a median follow‐up of 7.20 (IQR: 1.84–11.24) months, 100 (40%) patients have died, 48% of the deaths were SARS‐CoV‐2‐related. Forty (18.4%) HCC patients died within 30‐days. The death rate increase was significantly different according to the BCLC stage (6.10% [95% CI 2.24–12.74], 11.76% [95% CI 4.73–22.30], 20.69% [95% CI 11.35–31.96] and 34.52% [95% CI 17.03–52.78] for BCLC 0/A, B, C and D, respectively; p = .0017). The hazard ratio was 1.45 (95% CI 0.49–4.31; p = .5032) in BCLC‐B versus 0/A, and 3.13 (95% CI 1.29–7.62; p = .0118) in BCLC‐C versus 0/A in the competing risk Cox regression model. Nineteen out of 32 iCCA (59.4%) died, and 12 deaths were related to SARS‐CoV‐2 infection.ConclusionsThis is the largest cohort of liver cancer patients infected with SARS‐CoV‐2. It characterizes the 30‐day mortality risk of SARS‐CoV‐2 infected patients with HCC during this period.

Extrahepatic cholangiocarcinoma versus intrahepatic cholangiocarcinoma: A comparison of survival outcomes and use of palliative care in diagnosed patients.

e16192 Background: Cholangiocarcinoma (CCA), a malignancy of the biliary tract epithelium, is of increasing importance due to its rising incidence worldwide. However, it also remains one of the most lethal malignances with a survival rate ranging between 6-16 months. Despite poor outcomes, palliative care remains underutilized in CCA. Determining outcomes, and differences in various CCA types remains crucial in helping patients and clinicians make goal of care decisions with regards to aggressive treatment. Objectives:The objective of this study is to compare survival outcomes between intrahepatic (iCCA) and extrahepatic cholangiocarcinoma (eCCA). In addition, it aims to compare the utilization palliative care in either subtype, considering the high morbidity and mortality of the disease. Methods: Pooled cross-sectional observational study of the2004-2017 National Cancer Database (NCDB), which contains almost 400,000 records. The study population included de-identified records of patients with CCA; ages 18-90. Descriptive statistics (frequency, means, and standard deviations) were used. For survival analyses, the Kaplan-Meier method with log-rank test and a multivariate Cox regression model was used. Results: A total of 53,054 patients with CCA were identified. Of which, 63.4% had iCCA and 36.7% of patients had eCCA. There were statistically significant differences between the two cohorts in regard to sex, race/ethnicity, as well as in Charlson Co-Morbidity score. 65.2% of iCCA patients had advanced clinical stages III/IV as compared to 62.5% of eCCA patients. Higher percentage of iCCA patients had bone metastasis (7.8% vs 4.6 %, p < 0.001), pulmonary metastasis (11.5% vs 7.8%; p <0.001) and tumor size greater than 5 cm (62.1% vs 20.7%, p <0.001) compared to eCCA. Regarding treatment, patients with iCCA were more likely to receive multi-agent chemotherapy (35.0% vs 26.2 %, p<0.001). Although statistically significant differences for primary site surgical intervention (25.5% vs 25.0%, p<0.001), as well as for immunotherapy (6% vs 5.4%, p= 0.048), was found, they were not clinically significant. Patients with eCCA had a higher 90-day mortality (11.4% vs 8.2%, p <0.001), with 21% less likelihood of survival compared to iCCA patients (AOR:0.79, CI:0.74-0.84). Palliative care remained underutilized, with a lower utilization in iCCA (15.7% vs 12.5%, p <0.001). Conclusions: Our study demonstrated that iCCA patients have better survival outcomes compared to eCCA patients. This could be due to biological/genomic differences which warrant future investigation. Future clinical trials could also stratify for the location of CCA. Despite CCA’s poor prognosis, palliative care remained underutilized, with lower utilization rates in iCCA compared to eCCA.

FGFR2 fusion detection in plasma: A new era in the clinical monitoring of iCCA.

4085 Background: Actionable genetic alterations can be identified in over 50% of intrahepatic cholangiocarcinoma (iCCA). Since EMA approved Pemigatinib, a selective Fibroblast growth factor receptor 1-3 (FGFR1-3) inhibitor for the treatment of CCA with FGFR2 fusions or rearrangements, the screening of patients who may benefit from such targeted therapies is especially relevant. In addition, novel FGFR inhibitors that are effective for treatment of resistant mutant clones are under development. In patients with no available tissue for genomic profiling or at different timepoints after targeted therapy, NGS testing of circulating cell-free DNA (ccfDNA) would be the most convenient option. Hence, two important issues must be addressed: i) technical set-up and validation of detection of FGFR2 rearrangements in plasma, and ii) patient shedding in iCCA, in order to consider liquid biopsy for routine clinical care. Methods: We conducted a retrospective study in a cohort of 18 iCCA patients with known FGFR2 fusion or rearrangement events previously identified in tumor FFPE by NGS (FoundationOne CDx test). A custom-designed capture-based NGS panel for use in plasma or tissue (VHIO-iCCA test) was developed to detect FGFR2 rearrangements and other common altered genes in iCCA. After validating our VHIO-iCCA panel with fusion positive FFPE samples, a concordance study was conducted to evaluate the detection of FGFR2 fusion and rearrangements in matched-to-tissue timepoint plasmas. Finally, additional serial plasma samples taken during FGFR inhibitor treatment were also analyzed. Results: From the 18 rearrangement events previously detected with FoundationOne CDx, we were able to identify all 18 in FFPE samples and 15 in the paired plasma using our VHIO-iCCA panel, representing a 100% and 83% concordance, respectively. In the 3 discordant cases, no additional alterations were detected in plasma, indicating a lack of circulating tumor DNA (ctDNA) shedding. Serial sampling of these patients indicated persistent non-shedding. The analysis of fusion allele fraction (FAF) in serial plasma samples revealed that detection of fusion FGFR2 changed during treatment and correlated with best response. In general, patients with a stable FAF showed a SD, while patients which reduced FAF presented a PR. Conclusions: This extremely valuable set of cases has allowed us to validate our VHIO-iCCA panel to be used in tissue and plasma, and to determine that the sensitivity in plasma is >80%, making this a feasible option to avoid tissue biopsies, whenever patients cannot undergo the procedure and even to aid in cancer monitoring. Patient shedding is high in iCCA, yet a fraction of patients may not find a useful resource in liquid biopsy. For those who shed ctDNA, monitoring through the FAF may guide clinical management of iCCA.

CT-based deep learning enables early postoperative recurrence prediction for intrahepatic cholangiocarcinoma

Preoperatively accurate evaluation of risk for early postoperative recurrence contributes to maximizing the therapeutic success for intrahepatic cholangiocarcinoma (iCCA) patients. This study aimed to investigate the potential of deep learning (DL) algorithms for predicting postoperative early recurrence through the use of preoperative images. We collected the dataset, including preoperative plain computed tomography (CT) images, from 41 patients undergoing curative surgery for iCCA at multiple institutions. We built a CT patch-based predictive model using a residual convolutional neural network and used fivefold cross-validation. The prediction accuracy of the model was analyzed. We defined early recurrence as recurrence within a year after surgical resection. Of the 41 patients, early recurrence was observed in 20 (48.8%). A total of 71,081 patches were extracted from the entire segmented tumor area of each patient. The average accuracy of the ResNet model for predicting early recurrence was 98.2% for the training dataset. In the validation dataset, the average sensitivity, specificity, and accuracy were 97.8%, 94.0%, and 96.5%, respectively. Furthermore, the area under the receiver operating characteristic curve was 0.994. Our CT-based DL model exhibited high predictive performance in projecting postoperative early recurrence, proposing a novel insight into iCCA management.

Progression Patterns and Post-Progression Survival in Recurred Intrahepatic Cholangiocarcinoma Patients: A Novel Prognostic Nomogram Based on Multicenter Cohorts.

BackgroundThe post-progression survival (PPS) of recurred intrahepatic cholangiocarcinoma (iCCA) patients relates to the characteristics of tumor progression. Moreover, the prediction model of PPS in those patients has not been well established. This study aimed at developing a novel nomogram for predicting PPS in recurred iCCA patients.MethodClinical characteristics were retrospectively collected in 396 patients diagnosed with iCCA from cohorts of Sun Yat-sen University Cancer Center (SYSUCC) and the First Hospital of Dalian Medical University (FHDMU). The PPS in patients with different progression patterns was investigated. The nomogram of PPS was established with the Cox regression model in the primary cohort. Then the nomogram was verified in the external validation cohort.ResultsLiver progression was the commonest pattern (42.08%) in recurred iCCA patients, while patients with local LN progression had significantly better PPS than those with other patterns. The independent prognostic factors comprised elevated CEA levels, tumor differentiation, N stage 8th, adjuvant therapy, Local LN metastasis, Liver Metastasis only, and Multiple Metastasis. The nomogram constructed on these factors achieved satisfied C-indexes of 0.794 (95% CI 0.769–0.828) and 0.827 (0.779–0.876) for the training and validation cohorts, respectively. These values were significantly higher than those of the 8th TNM stage system (all p < 0.001). The recurred iCCA patients could be precisely classified into high- and low-risk groups according to the cutoff point of this nomogram (p < 0.01).ConclusionThe investigation of progression patterns and the development of this nomogram can offer new evidence to precisely postoperative and post-progression management of iCCA patients.

Incidence Trend and Competing Risk Analysis of Patients With Intrahepatic Cholangiocarcinoma: A Population-Based Study.

BackgroundIntrahepatic cholangiocarcinoma (ICCA) is a primary liver cancer characterized by rapid progression and poor prognosis. There are few effective tools for evaluating the prognosis of ICCA patients, and the use of liver transplantation (LT) of the treatment for ICCA is still controversial.MethodsWe analyzed ICCA incidence data and clinicopathological data from the Surveillance, Epidemiology, and End Results database. Prognostic predictors were identified by univariate and multivariate Cox regression analyses and then used to establish a nomogram. The prediction performance of the nomogram was evaluated with receiver operating characteristic (ROC) curves, calibration plots and decision curve analysis (DCA) plots. Propensity score matching (PSM) was used to balance the baseline data of patients undergoing LT and other operations, and then, univariate Cox regression analysis was used to evaluate the therapeutic value of LT for ICCA.ResultsThe incidence of ICCA increased significantly, from 0.6 per 100,000 in 2,000 to 1.3 per 100,000 in 2018. The median overall survival (OS) of the patients was 13 months, and the 1-, 3-, and 5-year OS rates were 51.40, 22.14, and 13.79%, respectively. Cox regression analysis showed that age under 60 years old, female, tumor size ≤ 50 mm, better differentiation, smaller range of tumor invasion, lack of distant metastasis, regional lymph node surgery and treatment were associated with a better prognosis. The ROC curves, calibration plots, and DCA plots showed that the nomogram had good discrimination and calibration power, as well as clinical utility. After PSM, the univariate Cox regression analysis showed no significant difference in OS between patients treated with LT and patients treated with other operations.ConclusionThe incidence of ICCA increased significantly. A nomogram with good predictive performance was developed to predict the OS of ICCA patients. LT might be considered as a potential option for some ICCA patients.

MICA/B-targeted antibody promotes NK cell–driven tumor immunity in patients with intrahepatic cholangiocarcinoma

ABSTRACT The major histocompatibility complex-class I chain related proteins A and B (MICA/B) is upregulated because of cellular stress and MICA/B shedding by cancer cells causes escape from NKG2D recognition favoring the emergence of cancers. Cholangiocarcinoma (CCA) is a relatively rare, though increasingly prevalent, primary liver cancer characterized by a late clinical presentation and a dismal prognosis. We explored the NKG2D-MICA/B axis in NK cells from 41 patients with intrahepatic cholangiocarcinoma (iCCA). The MICA/B-specific 7C6 mAb was used for ex vivo antibody-dependent cytotoxicity (ADCC) experiments using circulating, non tumor liver- and tumor-infiltrating NK cells against the HuCCT-1 cell line and patient-derived primary iCCA cells as targets. MICA/B were more expressed in iCCA than in non-tumoral tissue, MICA transcription being higher in moderately-differentiated compared with poorly-differentiated cancer. Serum MICA was elevated in iCCA patients in line with higher expression of ADAM10 and ADAM17 that are responsible for proteolytic release of MICA/B from tumor. Addition of 7C6 significantly boosted peripheral, liver- and tumor-infiltrating-NK cell degranulation and IFNγ production toward MICA/B-expressing established cell lines and autologous iCCA patient target cells. Our data show that anti-MICA/B drives NK cell anti-tumor activity, and provide preclinical evidence in support of 7C6 as a potential immunotherapeutic tool for iCCA.

Liver Transplantation for Intrahepatic Cholangiocarcinoma: What Are New Insights and What Should We Follow?

Intrahepatic cholangiocarcinoma (iCCA) is a complex malignancy carrying poor prognosis. Liver transplantation (LT) was historically contraindicated for iCCA, due to poor outcomes after LT. However, an increasing number of studies have challenged this premise, because LT alone or combined with neoadjuvant chemotherapy has achieved relatively satisfactory transplant outcomes in well selected iCCA cases. This current review based on existing clinical researches, evinced that LT might serve as a viable option in iCCA cases as follows: ① unresectable tumor restricted to 2 cm, along with context of chronic liver diseases; and ② unresectable tumor locally advanced within the liver (without extrahepatic metastasis or vascular invasion) but responses to tumor down-staging treatments (namely, systemic neoadjuvant therapy and/or locoregional therapy). On the contrary, it is recommended as contraindications in iCCA cases as follows: ① patients with tumor progression while waiting for a transplant (increase of diameter, macrovascular invasion, new nodules, escalation of carbohydrate antigen 19-9, or extrahepatic spread); ② patients with iCCA recurrence. Conclusively, tumor burden, tumor biology, and response to down-staging strategies should be taken into consideration before LT. Whereas, the concept of “locally advanced stage” remains to be defined in the future, especially the optimized combination of “maximum size of largest lesion”, “number of lesions”, with/without “tumor differentiation”, just like the Milan criteria which is widely used for hepatocellular carcinoma. Given the scarcity of donor organ, and also the debate about LT in iCCA, accurate consensus about LT for iCCA patients is still urgently warranted.

Intrahepatic cholangiocarcinoma: Tumour heterogeneity and its clinical relevance.

Treatment of intrahepatic cholangiocarcinoma (iCCA) is currently at a significant turning point due to the identification of isocitrate dehydrogenase (IDH) mutations and fibroblast growth factor receptor (FGFR) fusions that can be targeted with currently available therapies. Clinical trials of these targeted therapies have been promising, and the iCCA patients who may benefit from these targeted treatments can be identified by pathological examination prior to molecular investigations. This is because IDH mutations and FGFR fusions are mainly seen in the small duct type iCCA, a subtype of iCCA defined by the 5th World Health Organization classification, which can be recognized by the pathological diagnostic process. Therefore, pathology plays an important role in precision medicine for iCCA, not only in confirming the diagnosis, but also in identifying the iCCA patients who may benefit from targeted treatments. However, caution is advised with the pathological diagnosis, as iCCA shows tumour heterogeneity, making it difficult to distinguish small duct type iCCA from hepatocellular carcinoma (HCC), and combined HCC-CCA. This review focuses on the pathological/molecular features of both subtypes of iCCA (large and small duct types), as well as their diagnostic pitfalls, clinical relevance, and future perspectives.

Liver Transplantation for Intrahepatic Cholangiocarcinoma: Ready for Prime Time?

Cholangiocarcinoma (CCA) represents the second-most common primary liver malignancy after HCC and has risen in incidence globally in the past decades. Intrahepatic cholangiocarcinoma (iCCA) comprises 20% of all CCAs, with the rest being extrahepatic (including perihilar [pCCA] and distal CCA). Though long representing an absolute contraindication for liver transplantation (LT), recent analyses of outcomes of LT for iCCA have suggested that iCCA may be a potentially feasible option for highly selected patients. This has been motivated both by successes noted in outcomes of LT for other malignancies, such as HCC and pCCA, and by several retrospective reviews demonstrating favorable results with LT for a selected group of iCCA patients with small lesions. LT for iCCA is primarily relevant within two clinical scenarios. The first includes patients with very early disease (single tumor, ≤2 cm) with cirrhosis and are not candidates for liver resection (LR). The second scenario is patients with locally advanced iCCA, but where the extent of LR would be too extensive to be feasible. Preliminary single-center reports have described LT in a selected group of patients with locally advanced tumors who have responded to neoadjuvant therapy and have a period of disease stability. Currently, there are three prospective trials underway that will help clarify the role of LT in iCCA. This review seeks to explore the available studies involving LT for iCCA, the challenges of ongoing trials, and opportunities for the future.

Immunotherapies for hepatocellular carcinoma and intrahepatic cholangiocarcinoma: Current and developing strategies.

Liver cancer including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) is the third leading cause of cancer-related deaths worldwide. HCC arises from hepatocyte or hepatic stem cells, while iCCA originates from biliary epithelial cells, and the respective biological context are very different. Despite screening programs, the diagnosis of liver cancer is in most cases made when curative treatments such as surgery or ablation are not possible. In 2020, after a decade of using only tyrosine kinase inhibitors (TKI), a combination of an immune-check point inhibitor (ICI) and a VEGF antagonist proved superior to a TKI as first line therapy of advanced HCC. In 2022, the addition of an ICI to standard chemotherapy demonstrated an improvement of patient survival in iCCA. Moreover, ICI offer an unprecedented rate of durable responses to HCC and iCCA patients. Nevertheless, still two thirds of patients do not respond to ICI-based combinations, and research efforts are focused on deciphering the mechanisms of immune evasion of these lethal cancers. Reliable predictive and prognostic biomarkers are still lacking, but the molecular phenotyping of the tumor microenvironment is currently providing potential candidates for patient stratification. In this review, we will summarize the current knowledge on the immune biology of the liver, the discovery of cell-intrinsic and immune cell-mediated mechanisms of immune evasion by means of high-resolution single cell data, the main targets of current immunotherapy approaches, and the recent milestones in immunotherapy of HCC and iCCA.

YAP1 activation and Hippo pathway signaling in the pathogenesis and treatment of intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA), the second most common primary liver cancer, is a highly lethal epithelial cell malignancy exhibiting features of cholangiocyte differentiation. iCCAs can potentially develop from multiple cell types of origin within liver, including immature or mature cholangiocytes, hepatic stem cells/progenitor cells, and from transdifferentiation of hepatocytes. Understanding the molecular mechanisms and genetic drivers that diversely drive specific cell lineage pathways leading to iCCA has important biological and clinical implications. In this context, activation of the YAP1-TEAD dependent transcription, driven by Hippo-dependent or -independent diverse mechanisms that lead to the stabilization of YAP1 is crucially important to biliary fate commitment in hepatobiliary cancer. In preclinical models, YAP1 activation in hepatocytes or cholangiocytes is sufficient to drive their malignant transformation into iCCA. Moreover, nuclear YAP1/TAZ is highly prevalent in human iCCA irrespective of the varied etiology, and significantly correlates with poor prognosis in iCCA patients. Based on the ubiquitous expression and diverse physiologic roles for YAP1/TAZ in the liver, recent studies have further revealed distinct functions of active YAP1/TAZ in regulating tumor metabolism, as well as the tumor immune microenvironment. In the current review, we discuss our current understanding of the various roles of the Hippo-YAP1 signaling in iCCA pathogenesis, with a specific focus on the roles played by the Hippo-YAP1 pathway in modulating biliary commitment and oncogenicity, iCCA metabolism, and immune microenvironment. We also discuss the therapeutic potential of targeting the YAP1/TAZ-TEAD transcriptional machinery in iCCA, its current limitations, and what future studies are needed to facilitate clinical translation.

POSA354 Patient-Reported Outcomes in Futibatinib-Treated Intrahepatic Cholangiocarcinoma Patients with FGFR2 Fusions/Rearrangements: Results from the Foenix-CCA2 Study

We report patient-reported outcomes (PROs) results from the pivotal phase 2 trial FOENIX-CCA2 (NCT02052778). FOENIX-CCA2 evaluated futibatinib, an irreversible FGFR1–4 inhibitor, among intrahepatic cholangiocarcinoma (iCCA) patients with FGFR2 fusions/rearrangements. Futibatinib demonstrated a confirmed objective response rate of 41.7%; adverse events were manageable. PROs were a prespecified secondary objective of the study.

Mucosal-associated invariant T-cell tumor infiltration predicts long-term survival in cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a malignancy arising from biliary epithelial cells of intra- and extrahepatic bile ducts with dismal prognosis and few nonsurgical treatments available. Despite recent success in the immunotherapy-based treatment of many tumor types, this has not been successfully translated to CCA. Mucosal-associated invariant T (MAIT) cells are cytotoxic innate-like T cells highly enriched in the human liver, where they are located in close proximity to the biliary epithelium. Here, we aimed to comprehensively characterize MAIT cells in intrahepatic (iCCA) and perihilar CCA (pCCA). Liver tissue from patients with CCA was used to study immune cells, including MAIT cells, in tumor-affected and surrounding tissue by immunohistochemistry, RNA-sequencing, and multicolor flow cytometry. The iCCA and pCCA tumor microenvironment was characterized by the presence of both cytotoxic T cells and high numbers of regulatory T cells. In contrast, MAIT cells were heterogenously lost from tumors compared to the surrounding liver tissue. This loss possibly occurred in response to increased bacterial burden within tumors. The residual intratumoral MAIT cell population exhibited phenotypic and transcriptomic alterations, but a preserved receptor repertoire for interaction with tumor cells. Finally, the high presence of MAIT cells in livers of iCCA patients predicted long-term survival in two independent cohorts and was associated with a favorable antitumor immune signature. MAIT cell tumor infiltration associates with favorable immunological fitness and predicts survival in CCA.

Pattern of progression of intrahepatic cholangiocarcinoma: Implications for second-line clinical trials.

BackgroundIntrahepatic cholangiocarcinoma (iCCA) is the second most frequent liver cancer. The overall survival of iCCA and other biliary tract cancers (BTC) remains poor. Recently, the ABC‐06 trial reported the superiority of FOLFOX vs clinical observation as a second‐line treatment. Still, the survival benefit was less than expected. We hypothesized that the pattern of progression of iCCA can drive post‐progression survival (PPS), similar to hepatocellular carcinoma.MethodsMulticentre retrospective evaluation of consecutive iCCA patients who progressed after frontline systemic treatment with gemcitabine as monotherapy or in combination with platinum. Radiological assessment of progression was evaluated according to RECIST 1.1. The progression pattern was divided according to the presence/absence of new extrahepatic lesions (NEH).ResultsWe included 206 patients from 5 centres. The median OS was 14.1 months and its independent predictors (hazard ratio [HR], 95% confidence interval [CI]) were previous surgery 0.699 [0.509‐0.961], performance status >2.445 [1.788‐3.344], permanent first‐line discontinuation 16.072 [5.102‐50.633], registration of ascites 2.226 [1.448‐3.420] or bilirubin >3 mg/dl 3.004 [1.935‐4.664] during the follow‐up, and disease progression 2.523 [1.261‐5.050]. The appearance of NEH independently predicted OS 2.18 [1.55‐3.06] in patients with radiological progression. Amongst 138 patients eligible for second‐line treatment, PPS was 16.8 and 5.9 months in cases without and with NEH, respectively (P = .001). Progression owing to NEH lesions was an independent predictor of PPS 1.873 [1.333‐2.662], together with performance status, time to progression to the frontline treatment, bilirubin >3 mg/dl and ascites.ConclusionsPPS of iCCA is influenced by progression pattern, with important implications for second‐line trial design and analysis.

Integration of adeno-associated virus (AAV) into the genomes of most Thai and Mongolian liver cancer patients does not induce oncogenesis

BackgroundEngineered versions of adeno-associated virus (AAV) are commonly used in gene therapy but evidence revealing a potential oncogenic role of natural AAV in hepatocellular carcinoma (HCC) has raised concerns. The frequency of potentially oncogenic integrations has been reported in only a few populations. AAV infection and host genome integration in another type of liver cancer, cholangiocarcinoma (CCA), has been studied only in one cohort. All reported oncogenic AAV integrations in HCC come from strains resembling the fully sequenced AAV2 and partly sequenced AAV13. When AAV integration occurs, only a fragment of the AAV genome is detectable in later DNA or RNA sequencing. The integrated fragment is typically from the 3’ end of the AAV genome, and this positional bias has been only partly explained. Three research groups searched for evidence of AAV integration in HCC RNAseq samples in the Cancer Genome Atlas (TCGA) but reported conflicting results.ResultsWe collected and analyzed whole transcriptome and viral capture DNA sequencing in paired tumor and non-tumor samples from two liver cancer Asian cohorts from Thailand (N = 147, 47 HCC and 100 intrahepatic cholangiocarcinoma (iCCA)) and Mongolia (N = 70, all HCC). We found only one HCC patient with a potentially oncogenic integration of AAV, in contrast to higher frequency reported in European patients. There were no oncogenic AAV integrations in iCCA patients. AAV genomic segments are present preferentially in the non-tumor samples of Thai patients.By analyzing the AAV genome positions of oncogenic and non-oncogenic integrated fragments, we found that almost all the putative oncogenic integrations overlap the X gene, which is present and functional only in the strain AAV2 among all fully sequenced strains. This gene content difference could explain why putative oncogenic integrations from other AAV strains have not been reported.We resolved the discrepancies in previous analyses of AAV presence in TCGA HCC samples and extended it to CCA. There are 12 TCGA samples with an AAV segment and none are in Asian patients. AAV segments are present in preferentially in TCGA non-tumor samples, like what we observed in the Thai patients.ConclusionsOur findings suggest a minimal AAV risk of hepatocarcinogenesis in Asian liver cancer patients. The partial genome presence and positional bias of AAV integrations into the human genome has complicated analysis of possible roles of AAV in liver cancer.