OATP1B3 expression is strongly associated with Wnt/β-catenin signalling and represents the transporter of gadoxetic acid in hepatocellular carcinoma

Predicting Genomic Alterations of Phosphatidylinositol-3 Kinase Signaling in Hepatocellular Carcinoma: A Radiogenomics Study Based on Next-Generation Sequencing and Contrast-Enhanced CT

BACKGROUND

Exploring the genomic landscape of hepatocellular carcinoma (HCC) provides clues for therapeutic decision-making. Phosphatidylinositol-3 kinase (PI3K) signaling is one of the key pathways regulating HCC aggressiveness, and its genomic alterations have been correlated with sorafenib response. In this study, we aimed to predict somatic mutations of the PI3K signaling pathway in HCC samples through machine-learning-based radiomic analysis.

METHODS

HCC patients who underwent next-generation sequencing and preoperative contrast-enhanced CT were recruited from West China Hospital and The Cancer Genome Atlas for model training and validation, respectively. Radiomic features were extracted from volumes of interest (VOIs) covering the tumor (VOItumor) and peritumoral areas (5 mm [VOI5mm], 10 mm [VOI10mm], and 20 mm [VOI20mm] from tumor margin). Factor analysis, logistic regression analysis, least absolute shrinkage and selection operator, and random forest analysis were applied for feature selection and model construction. Model performance was characterized based on the area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 132 HCC patients (mean age: 61.1 ± 14.7 years; 108 men) were enrolled. In the training set, the AUCs of radiomic signatures based on single CT phases were moderate (AUC 0.694-0.771). In the external validation set, the radiomic signature based on VOI10mm in arterial phase demonstrated the highest AUC (0.733) among all models. No improvement in model performance was achieved after adding the tumor radiomic features or manually assessed qualitative features.

CONCLUSIONS

Machine-learning-based radiomic analysis had potential for characterizing alterations of PI3K signaling in HCC and could help identify potential candidates for sorafenib treatment.

Evaluating the Role of Hepatobiliary Phase of Gadoxetic Acid-Enhanced Magnetic Resonance Imaging in Predicting Treatment Impact of Lenvatinib and Atezolizumab plus Bevacizumab on Unresectable Hepatocellular Carcinoma

Simple Summary

Atezolizumab plus bevacizumab therapy has high response rates in patients with unresectable hepatocellular carcinoma (HCC). The hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) has been reported to be useful as an imaging biomarker for detecting β-catenin mutations. We evaluated whether pretreatment in the hepatobiliary phase of EOB-MRI could predict the therapeutic effect of lenvatinib (n = 33) and atezolizumab plus bevacizumab (n = 35). The visual assessment and relative enhancement ratio (RER) of the largest HCC lesions were evaluated using the hepatobiliary phase of EOB-MRI. In the lenvatinib group, progression-free survival (PFS) was not differently stratified using EOB-MRI. In the atezolizumab plus bevacizumab group, the heterogeneous type had significantly shorter PFS than the homogenous type, and the hyperintensity (RER ≥ 0.9) type had significantly shorter PFS than the hypointensity type. Hence, the hepatobiliary phase of EOB-MRI was useful for predicting the therapeutic effect of atezolizumab plus bevacizumab therapy on unresectable HCC.

Abstract

Background: Atezolizumab plus bevacizumab therapy has high response rates in patients with unresectable hepatocellular carcinoma (HCC). The hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) has been reported to be useful as an imaging biomarker for detecting β-catenin mutations. We evaluated whether the pretreatment of the hepatobiliary phase of EOB-MRI could predict the therapeutic effect of lenvatinib and atezolizumab plus bevacizumab. Methods: This study included 68 patients (lenvatinib group (n = 33) and atezolizumab plus bevacizumab group (n = 35)). The visual assessment and relative enhancement ratio (RER) of the largest HCC lesions were evaluated using the hepatobiliary phase of EOB-MRI. Results: The hyperintensity type (RER ≥ 0.9) was 18.2% in the lenvatinib group and 20.0% in the atezolizumab plus bevacizumab group. In the lenvatinib group, progression-free survival (PFS) was not different between the heterogeneous and homogenous types (p = 0.688) or between the hyperintensity and hypointensity types (p = 0.757). In the atezolizumab plus bevacizumab group, the heterogeneous type had significantly shorter PFS than the homogenous type (p = 0.007), and the hyperintensity type had significantly shorter PFS than the hypointensity type (p = 0.012). Conclusions: The hepatobiliary phase of EOB-MRI was useful for predicting the therapeutic effect of atezolizumab plus bevacizumab therapy on unresectable HCC.

Clinical Significance of the Duality of Wnt/β-Catenin Signaling in Human Hepatocellular Carcinoma

Combination therapy with immune checkpoint inhibitors (ICIs) and vascular endothelial growth factor inhibitors has been approved as a first-line treatment for unresectable hepatocellular carcinoma (HCC), indicating a critical role of ICIs in the treatment of HCC. However, 20% of patients do not respond effectively to ICIs; mutations in the activation of the Wnt/β-catenin pathway are known to contribute to primary resistance to ICIs. From this point of view, non-invasive detection of Wnt/β-catenin activation should be informative for the management of advanced HCC. Wnt/β-catenin mutations in HCC have a dual aspect, which results in two distinct tumor phenotypes. HCC with minimal vascular invasion, metastasis, and good prognosis is named the “Jekyll phenotype”, while the poorly differentiated HCC subset with frequent vascular invasion and metastasis, cancer stem cell features, and high serum Alpha fetoprotein levels, is named the “Hyde phenotype”. To differentiate these two HCC phenotypes, a combination of the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging and fluoro-2-deoxy-D-glucose-PET/CT may be useful. The former is applicable for the detection of the Jekyll phenotype, as nodules present higher enhancement on the hepatobiliary phase, while the latter is likely to be informative for the detection of the Hyde phenotype by showing an increased glucose uptake.

Role and Regulation of Wnt/β-Catenin in Hepatic Perivenous Zonation and Physiological Homeostasis

Metabolic heterogeneity or functional zonation is a key characteristic of the liver that allows different metabolic pathways to be spatially regulated within the hepatic system and together contribute to whole body homeostasis. These metabolic pathways are segregated along the portocentral axis of the liver lobule into three hepatic zones: periportal, intermediate or midzonal, and perivenous. The liver performs complementary or opposing metabolic functions within different hepatic zones while synergistic functions are regulated by overlapping zones, thereby maintaining the overall physiological stability. The Wnt/β-catenin signaling pathway is well known for its role in liver growth, development, and regeneration. In addition, the Wnt/β-catenin pathway plays a fundamental and dominant role in hepatic zonation and signals to orchestrate various functions of liver metabolism and pathophysiology. The β-catenin protein is the central player in the Wnt/β-catenin signaling cascade, and its activation is crucial for metabolic patterning of the liver. However, dysregulation of Wnt/β-catenin signaling is also implicated in different liver pathologies, including those associated with metabolic syndrome. β-Catenin is preferentially localized in the central region of the hepatic lobule surrounding the central vein and regulates multiple functions of this region. This review outlines the role of Wnt/β-catenin signaling pathway in controlling the different metabolic processes surrounding the central vein and its relation to liver homeostasis and dysfunction.

Current Landscape and Future Perspectives of Abbreviated MRI for Hepatocellular Carcinoma Surveillance

While ultrasound (US) is considered an important tool for hepatocellular carcinoma (HCC) surveillance, it has limited sensitivity for detecting early-stage HCC. Abbreviated MRI (AMRI) has recently gained popularity owing to better sensitivity in its detection of early-stage HCC than US, while also minimizing the time and cost in comparison to complete contrast-enhanced MRI, as AMRI includes only a few essential sequences tailored for detecting HCC. Currently, three AMRI protocols exist, namely gadoxetic acid-enhanced hepatobiliary-phase AMRI, dynamic contrast-enhanced AMRI, and non-enhanced AMRI. In this study, we discussed the rationale and technical details of AMRI techniques for achieving optimal surveillance performance. The strengths, weaknesses, and current issues of each AMRI protocol were also elucidated. Moreover, we scrutinized previously performed AMRI studies regarding clinical and technical factors. Reporting and recall strategies were discussed while considering the differences in AMRI protocols. A risk-stratified approach for the target population should be taken to maximize the benefits of AMRI and the cost-effectiveness should be considered. In the era of multiple HCC surveillance tools, patients need to be fully informed about their choices for better adherence to a surveillance program.

Gadoxetic acid uptake as a molecular imaging biomarker for sorafenib resistance in patients with hepatocellular carcinoma: a post hoc analysis of the SORAMIC trial

PURPOSE

Gadoxetic acid uptake on hepatobiliary phase MRI has been shown to correlate with ß-catenin mutation in patients with HCC, which is associated with resistance to certain therapies. This study aimed to evaluate the prognostic value of gadoxetic acid uptake on hepatobiliary phase MRI in patients with advanced HCC receiving sorafenib.

METHODS

312 patients with available baseline hepatobiliary phase MRI images received sorafenib alone or following selective internal radiation therapy (SIRT) within SORAMIC trial. The signal intensity of index tumor and normal liver parenchyma were measured on the native and hepatobiliary phase MRI images, and relative tumor enhancement higher than relative liver enhancement were accepted as high gadoxetic acid uptake, and its prognostic value was assessed using univariate and multivariate Cox proportional hazard models.

RESULTS

The median OS of the study population was 13.4 (11.8-14.5) months. High gadoxetic acid uptake was seen in 51 (16.3%) patients, and none of the baseline characteristics was associated with high uptake. In univariate analysis, high gadoxetic acid uptake was significantly associated with shorter overall survival (10.7 vs. 14.0 months, p = 0.005). Multivariate analysis confirmed independent prognostic value of high gadoxetic acid uptake (HR, 1.7 [1.21-2.3], p = 0.002), as well as Child-Pugh class (p = 0.033), tumor diameter (p = 0.002), and ALBI grade (p = 0.015).

CONCLUSION

In advanced HCC patients receiving sorafenib (alone or combined with SIRT), high gadoxetic acid uptake of the tumor on pretreatment MRI, a surrogate of ß-catenin mutation, correlates with shorter survival. Gadoxetic acid uptake status might serve in treatment decision-making process.

Current Perspectives on the Immunosuppressive Niche and Role of Fibrosis in Hepatocellular Carcinoma and the Development of Antitumor Immunity

Immune checkpoint inhibitors have become the mainstay of treatment for hepatocellular carcinoma (HCC). However, they are ineffective in some cases. Previous studies have reported that genetic alterations in oncogenic pathways such as Wnt/β-catenin are the important triggers in HCC for primary refractoriness. T-cell exhaustion has been reported in various tumors and is likely to play a prominent role in the emergence of HCC due to chronic inflammation and cirrhosis-associated immune dysfunction. Immunosuppressive cells including regulatory T-cells and tumor-associated macrophages infiltrating the tumor are associated with hyperprogressive disease in the early stages of immune checkpoint inhibitor treatment. In addition, stellate cells and tumor-associated fibroblasts create an abundant desmoplastic environment by producing extracellular matrix. This strongly contributes to epithelial to mesenchymal transition via signaling activities including transforming growth factor beta, Wnt/β-catenin, and Hippo pathway. The abundant desmoplastic environment has been demonstrated in pancreatic ductal adenocarcinoma and cholangiocarcinoma to suppress cytotoxic T-cell infiltration, PD-L1 expression, and neoantigen expression, resulting in a highly immunosuppressive niche. It is possible that a similar immunosuppressive environment is created in HCC with advanced fibrosis in the background liver. Although sufficient understanding is required for the establishment of immune therapies of HCC, further investigations are still required in this field.

Higher Enhancement Intrahepatic Nodules on the Hepatobiliary Phase of Gd-EOB-DTPA-Enhanced MRI as a Poor Responsive Marker of Anti-PD-1/PD-L1 Monotherapy for Unresectable Hepatocellular Carcinoma

Introduction

Immune checkpoint inhibitors (ICIs) are promising agents for the treatment of hepatocellular carcinoma (HCC). However, the establishment of noninvasive measure that could predict the response to ICIs is challenging. This study aimed to evaluate tumor responses to ICIs using the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI), which was shown to reflect Wnt/β-catenin activating mutation.

Methods

A total of 68 intrahepatic HCC nodules from 18 patients with unresectable HCC and Child-Pugh class A liver function who received anti-programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) monotherapy were enrolled in this study. All patients had viable intrahepatic lesions evaluable using the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI within the 6 months prior to the treatment. The relative enhancement ratio was calculated, and the time to nodular progression (TTnP) defined as 20% or more increase in each nodule was compared between higher or hypo-enhancement HCC nodules. Then, the progression-free survival (PFS) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) were compared between patients with and without HCC nodules with higher enhancement on hepatobiliary phase images.

Results

The median PFS was 2.7 (95% confidence interval [CI]: 1.4-4.0) months in patients with HCC nodules with higher enhancement (n = 8) and 5.8 (95% CI: 0.0-18.9) months in patients with hypointense HCC nodules (n = 10) (p = 0.007). The median TTnP of HCC nodules with higher enhancement (n = 23) was 1.97 (95% CI: 1.86-2.07) months and that of hypointense HCC nodules (n = 45) was not reached (p = 0.003). The ORR was 12.5% (1/8) versus 30.0% (3/10); the disease control rate was 37.5% (3/8) versus 70.0% (7/10), respectively, in patients with or without higher enhancement intrahepatic HCC nodules.

Conclusion

The TTnP on HCC nodules with higher enhancement and the median PFS in patients who carried higher enhancement intrahepatic HCC nodules were significantly shorter than those in hypointense HCC nodules with anti-PD-1/PD-L1 monotherapy. The intensity of the nodule on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is a promising imaging biomarker for predicting unfavorable response with anti-PD-1/PD-L1 monotherapy in patients with HCC.

Therapeutic efficacy of lenvatinib for hepatocellular carcinoma with iso‑high intensity in the hepatobiliary phase of Gd‑EOB‑DTPA‑MRI

Previous studies have reported that hepatocellular carcinoma (HCC) harboring WNT/β-catenin mutations exhibits iso-high intensity by gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI, i.e. EOB-MRI) during the hepatobiliary phase (HBP), thus indicating that EOB-MRI may help clinicians identify an immune exclusion class, which might not respond to treatment with immune checkpoint inhibitors. The present study analyzed the efficacy of lenvatinib for HCC with iso-high intensity during the HBP of EOB-MRI. Overall, 52 patients who underwent EOB-MRI for 140 HCC nodules were classified into iso-high-intensity and low-intensity groups during the HBP of EOB-MRI. The clinical and histological characteristics, and different responses to treatment of both groups were analyzed. The expression levels of β-catenin and glutamine synthetase, indicative of WNT/β-catenin mutations, were enhanced in the HCC with iso-high-intensity group. Nine patients had iso-high intensity, whereas 43 patients had low intensity. Tumor size was larger, and the levels of antagonist-II or vitamin K absence were higher in the iso-high-intensity group. Furthermore, 3/9 patients in the iso-high-intensity group had objective responses compared with 13/43 patients in the low-intensity group. Disease control was observed in 5/9 patients in the iso-high-intensity group and 26/43 patients in the low-intensity group. Median overall survival was 29.8 months for the iso-high-intensity group compared with 20.8 months for the low-intensity group. In the iso-high-intensity group, the median progression-free survival rate was 6.7 months compared with 5.6 months in the low-intensity group. No differences in best percentage change from baseline tumor size were observed in either group. Although few patients were included in this study, the present findings suggested that the efficacy of lenvatinib was unaffected by signal intensity during the HBP of EOB-MRI.

[Up-to-date Knowledge on the Pathological Diagnosis of Hepatocellular Carcinoma]

Hepatocellular carcinoma (HCC) has heterogeneous molecular and pathological features and biological behavior. Large-scale genetic studies of HCC were accumulated, and a pathological-molecular classification of HCC was proposed. Approximately 35% of HCCs can be classified into distinct histopathological subtypes according to their molecular characteristics. Among recently identified subtypes, macrotrabecular massive HCC, neutrophil-rich HCC, vessels encapsulating tumor clusters HCC, and progenitor phenotype HCC (HCC with CK19 expression) are associated with a poor prognosis, whereas the lymphocyte-rich HCC subtype is related to a better prognosis. This review provides up-to-date knowledge on the pathological diagnosis of HCC according to the updated World Health Organization Classification of Digestive System Tumors 5th ed.

Changing the Treatment Paradigm for Hepatocellular Carcinoma Using Atezolizumab plus Bevacizumab Combination Therapy

Atezolizumab plus bevacizumab combination therapy was approved worldwide for use in 2020. A 30% objective response rate with 8% complete response (CR) was achieved in a phase 3 IMbrave150 trial. Here, the change in the treatment strategy for hepatocellular carcinoma (HCC) using atezolizumab plus bevacizumab combination therapy is reviewed. The phase 3 IMbrave150 clinical trial was successful because of the direct antitumor effect of bevacizumab, which shifted the suppressive immune microenvironment to a responsive immune microenvironment, in addition to its synergistic effects when combined with atezolizumab. The analysis of CR cases was effective in patients with poor conditions, particularly tumor invasion in the main portal trunk (Vp4), making the combination therapy a breakthrough for HCC treatment. The response rate of the combination therapy was 44% against intermediate-stage HCC. Such a strong tumor-reduction effect paves the way for curative conversion (ABC conversion) therapy and, therefore, treatment strategies for intermediate-stage HCC may undergo a significant shift in the future. As these treatment strategies are effective in maintaining liver function, even in elderly patients, the transition frequency to second-line treatments could also be improved. These strategies may be effective against nonalcoholic steatohepatitis-related hepatocellular carcinoma and WNT/β-catenin mutations to a certain degree.

Higher Enhancement Intrahepatic Nodules on the Hepatobiliary Phase of Gd-EOB-DTPA-Enhanced MRI as a Poor Responsive Marker of Anti-PD-1/PD-L1 Monotherapy for Unresectable Hepatocellular Carcinoma

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are promising agents for the treatment of hepatocellular carcinoma (HCC). However, the establishment of noninvasive measure that could predict the response to ICIs is challenging. This study aimed to evaluate tumor responses to ICIs using the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI), which was shown to reflect Wnt/β-catenin activating mutation.

METHODS

A total of 68 intrahepatic HCC nodules from 18 patients with unresectable HCC and Child-Pugh class A liver function who received anti-programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) monotherapy were enrolled in this study. All patients had viable intrahepatic lesions evaluable using the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI within the 6 months prior to the treatment. The relative enhancement ratio was calculated, and the time to nodular progression (TTnP) defined as 20% or more increase in each nodule was compared between higher or hypo-enhancement HCC nodules. Then, the progression-free survival (PFS) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) were compared between patients with and without HCC nodules with higher enhancement on hepatobiliary phase images.

RESULTS

The median PFS was 2.7 (95% confidence interval [CI]: 1.4-4.0) months in patients with HCC nodules with higher enhancement (n = 8) and 5.8 (95% CI: 0.0-18.9) months in patients with hypointense HCC nodules (n = 10) (p = 0.007). The median TTnP of HCC nodules with higher enhancement (n = 23) was 1.97 (95% CI: 1.86-2.07) months and that of hypointense HCC nodules (n = 45) was not reached (p = 0.003). The ORR was 12.5% (1/8) versus 30.0% (3/10); the disease control rate was 37.5% (3/8) versus 70.0% (7/10), respectively, in patients with or without higher enhancement intrahepatic HCC nodules.

CONCLUSION

The TTnP on HCC nodules with higher enhancement and the median PFS in patients who carried higher enhancement intrahepatic HCC nodules were significantly shorter than those in hypointense HCC nodules with anti-PD-1/PD-L1 monotherapy. The intensity of the nodule on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is a promising imaging biomarker for predicting unfavorable response with anti-PD-1/PD-L1 monotherapy in patients with HCC.

Characteristics and Lenvatinib Treatment Response of Unresectable Hepatocellular Carcinoma with Iso-High Intensity in the Hepatobiliary Phase of EOB-MRI

Simple Summary

HCC with alterations in CTNNB1 (which encodes β-catenin) is resistant to immune checkpoint inhibitors and is associated with HCC with iso-high intensity in the hepatobiliary phase of EOB-MRI in resectable HCC. However, the prevalence, characteristics, mutation profile, and treatment response in unresectable HCC with iso-high intensity in the hepatobiliary phase of EOB-MRI are not well clarified. In this study, we showed that the prevalence was 13%, and the response to lenvatinib does not differ between HCC with and without iso-high intensity in the hepatobiliary phase of EOB-MRI. We analyzed CTNNB-1 mutations using cell-free DNA, providing support for their association with iso-high intensity in the hepatobiliary phase of EOB-MRI.

Abstract

In hepatocellular carcinoma (HCC), CTNNB-1 mutations, which cause resistance to immune checkpoint inhibitors, are associated with HCC with iso-high intensity in the hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) in resectable HCC; however, analyses on unresectable HCC are lacking. This study analyzed the prevalence, characteristics, response to lenvatinib, and CTNNB-1 mutation frequency in unresectable HCC with iso-high intensity in the hepatobiliary phase of EOB-MRI. In 52 patients with unresectable HCC treated with lenvatinib, the prevalence of iso-high intensity in the hepatobiliary phase of EOB-MRI was 13%. All patients had multiple HCCs, and 3 patients had multiple HCCs with iso-high intensity in the hepatobiliary phase of EOB-MRI. Lenvatinib response to progression-free survival and overall survival were similar between patients with or without iso-high intensity in the hepatobiliary phase of EOB-MRI. Seven patients (three and four patients who had unresectable HCC with or without iso-high intensity in the hepatobiliary phase of EOB-MRI, respectively) underwent genetic analyses. Among these, two (67%, 2/3) who had HCC with iso-high intensity in the hepatobiliary phase of EOB-MRI carried a CTNNB-1 mutation, while all four patients who had HCC without iso-high intensity in the hepatobiliary phase of EOB-MRI did not carry the CTNNB-1 mutation. This study’s findings have clinical implications for the detection and treatment of HCC with iso-high intensity in the hepatobiliary phase of EOB-MRI.

Decoding Genes: Current Update on Radiogenomics of Select Abdominal Malignancies

Technologic advances in chromosomal analysis and DNA sequencing have enabled genome-wide analysis of cancer cells, yielding considerable data on the genetic basis of malignancies. Evolving knowledge of tumor genetics and oncologic pathways has led to a better understanding of histopathologic features, tumor classification, tumor biologic characteristics, and imaging findings and discovery of targeted therapeutic agents. Radiogenomics is a rapidly evolving field of imaging research aimed at correlating imaging features with gene mutations and gene expression patterns, and it may provide surrogate imaging biomarkers that may supplant genetic tests and be used to predict treatment response and prognosis and guide personalized treatment options. Multidetector CT, multiparametric MRI, and PET with use of multiple radiotracers are some of the imaging techniques commonly used to assess radiogenomic associations. Select abdominal malignancies demonstrate characteristic imaging features that correspond to gene mutations. Recent advances have enabled us to understand the genetics of steatotic and nonsteatotic hepatocellular adenomas, a plethora of morphologic-molecular subtypes of hepatic malignancies, a variety of clear cell and non-clear cell renal cell carcinomas, a myriad of hereditary and sporadic exocrine and neuroendocrine tumors of the pancreas, and the development of targeted therapeutic agents for gastrointestinal stromal tumors based on characteristic KIT gene mutations. Mutations associated with aggressive phenotypes of these malignancies can sometimes be predicted on the basis of their imaging characteristics. Radiologists should be familiar with the genetics and pathogenesis of common cancers that have associated imaging biomarkers, which can help them be integral members of the cancer management team and guide clinicians and pathologists. Online supplemental material is available for this article. ^©RSNA, 2020 See discussion on this article by Luna (pp 1627-1630).

Immunological Microenvironment Predicts the Survival of the Patients with Hepatocellular Carcinoma Treated with Anti-PD-1 Antibody

INTRODUCTION

Although immune checkpoint inhibitors (ICIs) have been considered as promising agents for the treatment of advanced hepatocellular carcinoma (HCC), previous clinical trials revealed that the response to anti-programmed cell death protein 1 (anti-PD-1) monotherapy was as low as 20%. Identifying subgroups that respond well to ICIs is clinically important. Here, we studied the prognostic factors for anti-PD-1 antibody treatment based on the molecular and immunological features of HCC.

METHODS

Patients who were administered anti-PD1 antibody for advanced HCC at Kindai University Hospital were included. Clinicopathological backgrounds and antitumor responses were examined in 34 cases where tumor tissues before treatment were available. Transcriptome analysis was performed using 40 HCC samples obtained from surgical resection, and immune status was compared between 20 HCCs with activating mutations in β-catenin and those without the mutations using transcriptome-based immunogram.

RESULTS

Univariate analysis showed that the disease control rate was significantly better in patients with α-fetoprotein < 400 ng/mL, negative for β-catenin/glutamate synthetase (GS) staining, high combined positive score (CPS) of programmed death-ligand 1 (PD-L1), and increased infiltration of CD8⁺ cells in tumor tissues. Among them, negative staining of β-catenin/GS, CPS of PD-L1 ≥ 1, and high degree of CD8⁺ tumor-infiltrating lymphocytes (TILs) were significantly associated with longer survival in both progression-free survival (PFS) and overall survival (OS). The combination of these factors well stratified the survival of the patients on anti-PD-1 antibody in both PFS and OS (p < 0.0001 and p = 0.0048 for PFS and OS, respectively). In addition, the immunogram revealed that tumor-carrying mutations in β-catenin showed downregulation of immune-related genes, especially in those related to priming and activation by dendritic cells, interferon-γ response, inhibitory molecules, and regulatory T cells.

DISCUSSION/CONCLUSION

The combined score including Wnt/β-catenin activation, CPS of PD-L1, and degree of CD8⁺ TILs in HCC is informative for predicting the response to ICI in HCC cases. Constitutive activation of β-catenin can induce an immune cold phenotype with downregulation of immune-related genes, and immunohistochemistry-based evaluation is beneficial for identifying the subgroup that shows a good response to ICI.

Mn(II) Complex of Lipophilic Group-Modified Ethylenediaminetetraacetic Acid (EDTA) as a New Hepatobiliary MRI Contrast Agent

Liver-specific contrast agents (CAs) can improve the Magnetic resonance imaging (MRI) detection of focal and diffuse liver lesions by increasing the lesion-to-liver contrast. A novel Mn(II) complex, Mn-BnO-TyrEDTA, with a lipophilic group-modified ethylenediaminetetraacetic acid (EDTA) structure as a ligand to regulate its behavior in vivo, is superior to Gd-EOB-DTPA in terms of a liver-specific MRI contrast agent. An MRI study on mice demonstrated that Mn-BnO-TyrEDTA can be rapidly taken up by hepatocytes with a combination of hepatobiliary and renal clearance pathways. Bromosulfophthalein (BSP) inhibition imaging, biodistribution, and cellular uptake studies confirmed that the mechanism of hepatic targeting of Mn-BnO-TyrEDTA is the hepatic uptake of the amphiphilic anion contrast agent mediated by organic anion transporting polypeptides (OATPs) expressed by functional hepatocytes.

Histological Heterogeneity of Primary Liver Cancers: Clinical Relevance, Diagnostic Pitfalls and the Pathologist's Role

Simple Summary

Primary liver cancers (PLCs) mainly comprise hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (iCCA), and combined (c)HCC-CCA. Both small duct types iCCA (a subtype pf iCCA) and cHCC-CCA are known to be tumors with histological heterogeneity. Understanding key tumor heterogeneity is crucial as it reflects tumor aggressiveness, patient outcome, treatment choice, and is predictive of treatment efficacy. In addition, PLCs often present with multiple liver tumors, which can be a combination of different types of PLCs or HCCs (intrahepatic metastasis or multicentric occurrence), and the pathological interpretation plays an important role in these cases. The aim of this review is to clarify the pathological features of HCC, iCCA, and cHCC-CCA, including their diagnostic pitfalls, molecular profiles, and the correlation between tumor subtypes and treatment choice.

Abstract

Primary liver cancers (PLCs) mainly comprise hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (iCCA), and cHCC-CCA. Combined HCC-CCA and small duct type iCCA show similar clinical presentations, and their histological features are more complex than seen in HCC. Therefore, while their treatment strategy differs, it is difficult to properly diagnose these tumors. Currently, HCC is the only tumor that can be treated by liver transplantation. In addition, small duct type iCCA harbors IDH1/2 mutations and FGFR2 fusions, which can be used for targeted therapy. Thus, improving diagnostic accuracy is crucial. A further point to note is that PLCs often present as multiple liver tumors, and they can be a combination of different types of PLCs or HCCs. In the case of HCCs, two different scenarios are possible, namely intrahepatic metastasis, or multicentric occurrence. Therefore, it is essential to characterize the type of multiple liver tumors. This review aims to clarify the pathological features of HCC, iCCA and cHCC-CCA, including their diagnostic pitfalls and clinical relevance. It is designed to be of use to clinicians who are dealing with PLCs, to provide a better understanding of the pathology of these tumors, and to enable a more accurate diagnosis and optimal treatment choice.

Hepatocellular carcinoma: a clinical and pathological overview

HCC incidence rates have been rising in the past 3 decades and by 2025 > 1 million individuals will be affected annually. High-throughput sequencing technologies led to the identification of several molecular HCC subclasses that can be broadly grouped into 2 major subgroups, each characterized by specific morphological and phenotypical features. It is likely that this increasing knowledge and a more appropriate characterization of HCC at the pathological level will impact HCC patient management.

Pilot study of gadoxetate disodium-enhanced mri for localized and metastatic prostate cancers

OATP1B3 is expressed de novo in primary prostate cancer tissue and to a greater degree in prostate cancer metastases. Gadoxetate disodium is a substrate of OATP1B3, and its uptake has been shown to correlate with OATP1B3 expression in other cancers. We aimed to evaluate use of gadoxetate disodium to image prostate cancer and to track its utility as a biomarker. A single center open-label non-randomized pilot study recruited men with (1) localized, and (2) metastatic castration resistant prostate cancer (mCRPC). Gadoxetate disodium-enhanced MRI was performed at four timepoints post-injection. The Wilcoxon signed rank test was used to compare MRI contrast enhancement ratio (CER) pre-injection and post-injection. OATP1B3 expression was evaluated via immunohistochemistry (IHC) and a pharmacogenomic analysis of OATP1B3, NCTP and OATP1B1 was conducted. The mCRPC subgroup (n = 9) demonstrated significant enhancement compared to pre-contrast images at 20-, 40- and 60-min timepoints (p < 0.0078). The localized cancer subgroup (n = 11) demonstrated earlier enhancement compared to the mCRPC group, but no retention over time (p > 0.05). OATP1B3 expression on IHC trended higher contrast enhancement between 20–40 min (p ≤ 0.064) and was associated with contrast enhancement at 60 min (p = 0.0422). OATP1B1 haplotype, with N130D and V174A substitutions, impacted enhancement at 40–60 min (p ≤ 0.038). mCRPC lesions demonstrate enhancement after injection of gadoxetate disodium on MRI and retention over 60 min. As inter-individual variability in OATP1B3 expression and function has both predictive and prognostic significance, gadoxetate disodium has potential as a biomarker in prostate cancer.

OATP1B3 Expression in Hepatocellular Carcinoma Correlates with Intralesional Gd-EOB-DTPA Uptake and Signal Intensity on Gd-EOB-DTPA-Enhanced MRI

BACKGROUND

To evaluate the predictive value of the OATP1B3 expression in hepatocellular carcinoma (HCC) for the gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) uptake and the signal intensity (SI) in the hepatobiliary (HB) phase.

METHODS

In this retrospective study, we analyzed 69 liver nodules of 64 patients who underwent Gd-EOB-DTPA enhancement magnetic resonance imaging (MRI) before operation. Based on the SI in the HB phase, the patients were categorized into the hypointense HCC and iso- or hyperintense HCC groups. The OATP1B3 expression was detected by polymerase chain reaction (PCR) and immunohistochemistry. The differences between the expression of OATP1B3 and Gd-EOB-DTPA enhanced magnetic resonance imaging between the two groups of hepatocellular carcinoma were compared. The relationship between the OATP1B3 expression and the SI and relative enhancement (RE) was analyzed.

RESULTS

The examined HCC nodules were 59 hypointense HCC and 10 iso- or hyperintense. The relative expressions of OATP1B3, HB-phase signal, and the RE of the HB phase in iso- or hyperintense were significantly higher than those of the hypointense HCC, while the RE of the HB phase increased with an increase in the OATP1B3 expression (P < 0.05).

CONCLUSION

The OATP1B3 expression in HCC can predict the uptake of Gd-EOB-DTPA and the SI of the HB phase. We believe that the evaluation of OATP1B3 expression will facilitate the comprehension of imaging performance of HCC in Gd-EOB-DTPA-enhanced MRI.

Spectrum of liver lesions hyperintense on hepatobiliary phase: an approach by clinical setting

Hepatobiliary MRI contrast agents are increasingly being used for liver imaging. In clinical practice, most focal liver lesions do not uptake hepatobiliary contrast agents. Less commonly, hepatic lesions may show variable signal characteristics on hepatobiliary phase. This pictorial essay reviews a broad spectrum of benign and malignant focal hepatic observations that may show hyperintensity on hepatobiliary phase in various clinical settings. In non-cirrhotic patients, focal hepatic observations that show hyperintensity in the hepatobiliary phase are usually benign and typically include focal nodular hyperplasia. In patients with primary or secondary vascular disorders, focal nodular hyperplasia-like lesions arise as a local hyperplastic response to vascular alterations and tend to be iso- or hyperintense in the hepatobiliary phase. In oncologic patients, metastases and cholangiocarcinoma are hypointense lesions in the hepatobiliary phase; however, occasionally they may show a diffuse, central and inhomogeneous hepatobiliary paradoxical uptake with peripheral rim hypointensity. Post-chemotherapy focal nodular hyperplasia-like lesions may be tricky, and their typical hyperintense rim in the hepatobiliary phase is very helpful for the differential diagnosis with metastases. In cirrhotic patients, hepatocellular carcinoma may occasionally appear hyperintense on hepatobiliary phase.

Clinico-Radio-Pathological and Molecular Features of Hepatocellular Carcinomas with Keratin 19 Expression

Hepatocellular carcinoma (HCC) is a heterogeneous neoplasm, both from the molecular and histomorphological aspects. One example of heterogeneity is the expression of keratin 19 (K19) in a subset (4-28%) of HCCs. The presence of K19 expression in HCCs has important clinical implications, as K19-positive HCCs have been associated with aggressive tumor biology and poor prognosis. Histomorphologically, K19-positive HCCs demonstrate a more infiltrative appearance, poor histological differentiation, more frequent vascular invasion, and more intratumoral fibrous stroma than K19-negative conventional HCCs. From the molecular aspect, K19-positive HCCs have been matched with various gene signatures that have been associated with stemness and poor prognosis, including the G1-3 groups, S2 class, cluster A, proliferation signature, and vascular invasion signature. K19-positive HCCs also show upregulated signatures related to transforming growth factor-β pathway and epithelial-to-mesenchymal transition. The main regulators of K19 expression include hepatocyte growth factor-MET paracrine signaling by cancer-associated fibroblast, epidermal growth factor-epidermal growth factor receptor signaling, laminin, and DNA methylation. Clinically, higher serum alpha-fetoprotein levels, frequent association with chronic hepatitis B, more invasive growth, and lymph node metastasis have been shown to be characteristics of K19-positive HCCs. Radiologic features including atypical enhancement patterns, absence of tumor capsules, and irregular tumor margins can be a clue for K19-positive HCCs. From a therapeutic standpoint, K19-positive HCCs have been associated with poor outcomes after curative resection or liver transplantation, and resistance to systemic chemotherapy and locoregional treatment, including transarterial chemoembolization and radiofrequency ablation. In this review, we summarize the currently available knowledge on the clinico-radio-pathological and molecular features of K19-expressing HCCs, including a detailed discussion on the regulation mechanism of these tumors.

Clinical implications of WNT/β-catenin signaling for hepatocellular carcinoma

Immune checkpoint inhibitors have entered clinical practice for the treatment of hepatocellular carcinoma (HCC). Several previous studies for other cancers have revealed that tumor mutation burden, tumor PD-L1 expression and cytotoxic T-cell infiltration are predictive of treatment response. The genetic analysis of HCC has shown that β-catenin mutation might be a biomarker predicting the poor response against immune checkpoint inhibitors. β-catenin is a transcription factor downstream of WNT signaling and somatic mutations of this gene are the third most common in HCC. WNT signaling is an important signal for organogenesis and is also involved in the maintenance of stem cells in several organs. Recently, clinical and basic studies have shown the specific roles of WNT/β-catenin signaling in many aspects of hepatic function and carcinogenesis including metabolic zonation and inflammation, and sub-classification and radiologic features of HCC. Base on the review on the recent advances of research investigating WNT/β-catenin signaling associated with hepatocytes, we speculate the clinical role of this signal on the immunotherapy for HCC, which suggests that an era of genetic mutation profiles may be coming to add to the HCC treatment algorithm.

Impaired Transport Activity of Human Organic Anion Transporters (OATs) and Organic Anion Transporting Polypeptides (OATPs) by Wnt Inhibitors

The Wnt/β-catenin signaling pathway is dysregulated in diseases and Wnt inhibitors like PRI-724 are in clinical development. This study evaluated the regulatory actions of PRI-724 and other Wnt inhibitors on the transport activity of human renal Organic anion transporters (OATs) and Organic anion transporting polypeptides (OATPs). The substrate uptake by OAT4 and OATP2B1 was markedly decreased by PRI-724 (V_max/K_m: ∼26% and ∼17% of corresponding control), with less pronounced decreases in OAT1, OAT3 and OAT1A2. PRI-724 decreased the plasma membrane expression of inhibited OATs/OATPs but didn't affect their total cellular expression. Two model Wnt inhibitors - FH535 and 21H7 - were also tested in comparative studies. Like PRI-724, they also strongly decreased the activities and membrane expression of multiple OATs/OATPs. In contrast, FH535 didn't affect the substrate uptake by organic cation transporters. In control studies, the EGFR inhibitor lapatinib did not inhibit the function of some OATs/OATPs. Together these findings suggest that Wnt inhibitors selectively modulate the function of multiple organic anions transporters, so their clinical use may have unanticipated effects on drug entry into cells. These findings are pertinent to current clinical trials that have been designed to understand the safety and efficacy of new Wnt inhibitor drugs.

Application of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver, and its morbidity and mortality have been increasing in recent years. The early diagnosis and prompt treatment of small HCC are crucial to improve the prognosis and quality of life of patients. In China, hepatitis B virus infection is the main cause. HCC with a single tumor nodule of ≤ 3 cm in diameter, or HCC with a number of nodules, in which each nodule is ≤ 2 cm in diameter, with a total diameter of ≤ 3 cm, is considered as small HCC. The MRI liver-specific contrast agent can detect small HCC at the early stage. This has important clinical implications for improving the survival rate of patients.

MAIN BODY

Gd-EOB-DTPA-enhanced MRI can significantly improve the sensitivity and specificity of the detection of HBV-related small hepatocellular carcinoma, providing an important basis for the clinical selection of appropriate personalized treatment. Gd-EOB-DTPA-enhanced MRI can reflect the degree of HCC differentiation, and the evaluation of HCC on Gd-EOB-DTPA-enhanced MRI would be helpful for the selection of the treatment and prognosis of HCC patients. The present study reviews the progress of the application of Gd-EOB-DTPA in the early diagnosis of small HCC, its clinical treatment, the prediction of the degree of differentiation, and the assessment of recurrence and prognosis of HCC, including the pharmacoeconomics and application limitations of Gd-EOB-DTPA. The value of the application of HCC with the Gd-EOB-DTPA was summarized to provide information for improving the quality of life and prolonging the survival of patients.

CONCLUSION

Gd-EOB-DTPA-enhanced MRI has the diagnostic capability for small HCC with a diameter of ≤ 2 cm. This will have a broader application prospect in the early diagnosis of small liver cancer with a diameter of ≤ 1 cm in the future. The relationship between GD-EOB-DTPA-MRI and the degree of HCC differentiation has a large research space, and Gd-EOB-DTPA is expected to become a potential tool for the preoperative prediction and postoperative evaluation of HCC, which would be beneficial for more appropriate treatments for HCC patients.

Low expression of organic anion-transporting polypeptide 1B3 predicts a poor prognosis in hepatocellular carcinoma

Objective

To detect the expression level of organic anion-transporting polypeptide 1B3 (OATP1B3) in hepatocellular carcinoma (HCC) and to determine the relationship between OATP1B3 expression, clinicopathological features, and prognosis.

Methods

Immunohistochemical (IHC) staining was performed to detect the expression of OATP1B3 in 131 HCC specimens and in 89 adjacent nontumorous tissues. Moreover, the expression levels of OATP1B3 in 30 pairs of tumor and matched adjacent nontumorous tissues were detected by quantitative real-time polymerase chain reaction, and 34 pairs of tumor and matched adjacent nontumorous tissues were detected by Western blotting. The χ² test was applied to analyze the correlation between OATP1B3 expression and the clinical parameters of HCC patients. The prognostic value of OATP1B3 in HCC patients was estimated by Kaplan-Meier survival analysis and the Cox stepwise proportional hazards model.

Results

Compared with that in adjacent nontumorous tissues (25.8%, 23/89), OATP1B3 expression was significantly downregulated in tumor tissues (59.5%, 78/131) (P < 0.0001). Moreover, OATP1B3 expression was markedly correlated with tumor size, recurrence, tumor differentiation, and tumor node metastasis (TNM) stage (P < 0.05 for each). However, age, sex, tumor capsule status, HBsAg, cirrhosis, tumor number, vascular invasion, and serum alpha fetoprotein were not associated with OATP1B3 expression. The overall survival (OS) and disease-free survival (DFS) of HCC patients who had high expression of OATP1B3 were significantly longer than those of patients with low expression (33.0% vs 12.9%, P = 0.001; 18.8% vs 5.3%, P < 0.0001). Cox multivariate analysis showed that OATP1B3, invasion, and TNM stage (P < 0.05 for each) were independent prognostic factors of OS in HCC patients and that OATP1B3 and TNM stage (both P < 0.05) were independent prognostic factors of DFS in HCC patients.

Conclusions

The expression of OATP1B3 in HCC patients was significantly lower than that in adjacent nontumorous tissues. OATP1B3 expression may be a potential prognostic marker in HCC patients.

Quantification of intratumoral collagen and elastin fibers within hepatocellular carcinoma tissues finds correlations with clinico-patho-radiological features

AIM

Emerging evidence suggests a promising role for tumor stromal factors in characterizing patients with various types of malignancies, including hepatocellular carcinoma (HCC). We quantified the amount of collagen and elastin fibers in HCC samples with the aim of clarifying the clinico-patho-radiological significance of fiber deposition in HCC.

METHODS

We computed the amount of collagen and elastin fibers using digital image analysis of whole-slide images of Elastica van Gieson-stained tissues from 156 surgically resected HCCs. Furthermore, we assessed the correlations between the fiber content of HCC samples and clinical, pathological, and radiological features, including immunohistochemistry-based molecular subtypes and immunosubtypes.

RESULTS

The intratumoral area ratio of collagen in HCC tissues (median 3.4%, range 0.1-22.2%) was more than threefold that of elastin (median 0.9%, range 0.1-9.0%); there was a strong positive correlation between the amounts of collagen and elastin. Higher levels of combined collagen and elastin were significantly associated with the confluent multinodular macroscopic tumor type, the absence of a fibrous capsule, intratumoral steatosis, scirrhous tumor stroma, dense inflammatory-cell infiltrates, and the biliary/stem cell markers-positive HCC subtype. The associations of higher collagen levels with radiological findings, including heterogeneous enhancement and persistent enhancement on dynamic computed tomography, were significant. In contrast, the associations of radiological findings with elastin fibers were not significant. Intratumoral fibrous stroma in HCC comprised septum-like and perisinusoidal fibrosis; these two forms represented distinct distribution patterns of fibers and fibroblasts.

CONCLUSION

Quantitative analysis suggested that stromal fiber-rich HCCs likely represent a distinct clinico-patho-radiological entity.

Value of T1 mapping on gadoxetic acid-enhanced MRI for microvascular invasion of hepatocellular carcinoma: a retrospective study

BACKGROUND

To evaluate the utility of non-invasive parameters derived from T1 mapping and diffusion-weighted imaging (DWI) on gadoxetic acid-enhanced MRI for predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC).

METHODS

A total of 94 patients with single HCC undergoing partial hepatectomy was analyzed in this retrospective study. Preoperative T1 mapping and DWI on gadoxetic acid-enhanced MRI was performed. The parameters including precontrast, postcontrast and reduction rate of T1 relaxation time and apparent diffusion coefficient (ADC) values were measured for differentiating MVI-positive HCCs (n = 38) from MVI-negative HCCs (n = 56). The receiver operating characteristic curve (ROC) was analyzed to compare the diagnostic performance of the calculated parameters.

RESULTS

MVI-positive HCCs demonstrated a significantly lower reduction rate of T1 relaxation time than that of MVI-negative HCCs (39.4% vs 49.9, P < 0.001). The areas under receiver operating characteristic curve (AUC) were 0.587, 0.728, 0.824, 0,690 and 0.862 for the precontrast, postcontrast, reduction rate of T1 relaxation time, ADC and the combination of reduction rate and ADC, respectively. The cut-off value of the reduction rate and ADC calculated through maximal Youden index in ROC analyses was 44.9% and 1553.5 s/mm². To achieve a better diagnostic performance, the criteria of combining the reduction rate lower than 44.9% and the ADC value lower than 1553.5 s/mm² was proposed with a high specificity of 91.8% and accuracy of 80.9%.

CONCLUSIONS

The proposed criteria of combining the reduction rate of T1 relaxation time lower than 44.9% and the ADC value lower than 1553.5 s/mm² on gadoxetic acid-enhanced MRI holds promise for evaluating MVI status of HCC.

Gadoxetic acid-enhanced MR imaging for hepatocellular carcinoma: molecular and genetic background

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) plays important roles in diagnosis of hepatic lesions because of its superiority in the detectability of small lesions, its differentiation ability, and its utility for the early diagnosis of hepatocellular carcinoma (HCC). In HCC, expression of organic anion transporting polypeptide (OATP) 1B3 correlates with the enhancement ratio in the hepatobiliary phase. Gadoxetic acid-enhanced MRI, an indirect molecular imaging method, reflects OATP1B3 expression in HCC. OATP1B3 expression gradually decreases from the dysplastic nodule stage to advanced HCC. Decreased expression is a sensitive marker of multistep hepatocarcinogenesis, especially in the early stages. Hypervascular HCCs commonly show hypointensity in the hepatobiliary phase corresponding to a decrease in OATP1B3; however, approximately 10% of HCCs show hyperintensity due to OATP1B3 overexpression. This hyperintense HCC shows less aggressive biological features and has a better prognosis than hypointense HCC. Hyperintense HCC can be classified into a genetic subtype of HCC with a mature hepatocyte-like molecular expression. OATP1B3 expression and the less aggressive nature of hyperintense HCC are regulated by the molecular interaction of β-catenin signaling and hepatocyte nuclear factor 4α, a tumor suppressor factor. Gadoxetic acid-enhanced MR imaging has the potential to be an imaging biomarker for HCC. KEY POINTS: • The hepatobiliary phase is a sensitive indirect indicator of organic anion transporting polypeptide1B3 (OATP1B3) expression in hepatocellular carcinoma (HCC). • The OATP1B3 expression, namely, enhancement in the hepatobiliary phase, decreases from the very early stage of hepatocarcinogenesis, contributing to early diagnosis of HCC. • HCC showing hyperintensity on the hepatobiliary phase is a peculiar genetic subtype of HCC with OATP1B3 overexpression, a less aggressive nature, and mature hepatocyte-like molecular/genetic features.

Precision pathology analysis of the development and progression of hepatocellular carcinoma: Implication for precision diagnosis of hepatocellular carcinoma

Outcomes for patients with hepatocellular carcinoma (HCC) remain poor because the condition is often unresponsive to the available treatments. Consequently, the early and precise diagnosis of HCC is crucial to achieve improvements in prognosis. For patients with chronic liver disease, the assessment of liver fibrosis is also important to ascertain both the staging of fibrosis and the risk of HCC occurrence. Early HCC was first described in 1991 in Japan and was defined internationally in 2009. As the concept of early HCC spread, the multistage hepatocarcinogenesis process became accepted. Consequently, improvements in imaging technology made the early diagnosis of HCC possible. At present, the most appropriate therapeutic strategy for HCC is determined using an integrated staging system that assesses the tumor burden, the degree of liver dysfunction and the patient performance status; however, pathological and molecular features are not taken into account. The recent introduction of several new therapeutic agents will change the treatment strategy for HCC. Against this background, HCC subclassification based on tumor cellular and microenvironmental characteristics will become increasingly important. In this review, we give an overview of how pathological analysis contributes to understanding the development and progression of HCC and establishing a precision diagnosis of HCC.

Overview of organic anion transporters and organic anion transporter polypeptides and their roles in the liver

Organic anion transporters (OATs) and organic anion transporter polypeptides (OATPs) are classified within two SLC superfamilies, namely, the SLC22A superfamily and the SLCO superfamily (formerly the SLC21A family), respectively. They are expressed in many tissues, such as the liver and kidney, and mediate the absorption and excretion of many endogenous and exogenous substances, including various drugs. Most are composed of 12 transmembrane polypeptide chains with the C-terminus and the N-terminus located in the cell cytoplasm. OATs and OATPs are abundantly expressed in the liver, where they mainly promote the uptake of various endogenous substrates such as bile acids and various exogenous drugs such as antifibrotic and anticancer drugs. However, differences in the locations of glycosylation sites, phosphorylation sites, and amino acids in the OAT and OATP structures lead to different substrates being transported to the liver, which ultimately results in their different roles in the liver. To date, few articles have addressed these aspects of OAT and OATP structures, and we study further the similarities and differences in their structures, tissue distribution, substrates, and roles in liver diseases.

Gadoxetate-enhanced Abbreviated MRI for Hepatocellular Carcinoma Surveillance: Preliminary Experience

Purpose

To describe a single-center preliminary experience with gadoxetate disodium-enhanced abbreviated MRI for hepatocellular carcinoma (HCC) screening and surveillance in patients with cirrhosis or chronic hepatitis B virus (cHBV).

Materials and Methods

This was a retrospective study of consecutive patients aged 18 years and older with cirrhosis or cHBV who underwent at least one gadoxetate-enhanced abbreviated MRI examination for HCC surveillance from 2014 through 2016. Examinations were interpreted prospectively by one of six abdominal radiologists for clinical care. Clinical, imaging, and other data were extracted from electronic medical records. Diagnostic adequacy was assessed in all patients. Diagnostic accuracy was assessed in the subset of patients who could be classified as having HCC or not having HCC on the basis of a composite reference standard.

Results

In this study, 330 patients (93% with cirrhosis; 45% women; mean age, 59 years) underwent gadoxetate-enhanced abbreviated MRI. In the 330 patients, 311 (94.2%) baseline gadoxetate-enhanced abbreviated MRI examinations were diagnostically adequate. Of 141 (43%) of the 330 patients, 91.4% (129 of 141) could be classified as not having HCC and 8.6% (12 of 141) could be classified as having HCC. Baseline gadoxetate-enhanced abbreviated MRI had 0.92 sensitivity (95% confidence interval [CI]: 0.62, 1.00) and 0.91 specificity (95% CI: 0.84, 0.95) for detection of HCC. Of the 330 patients who underwent baseline gadoxetate-enhanced abbreviated MRI, 187 (57%) were lost to follow-up.

Conclusion

Gadoxetate-enhanced abbreviated MRI is feasible clinically, has a high diagnostic adequacy rate, and, on the basis of our preliminary experience, accurately depicts HCC in high-risk patients. Strategies to enhance follow-up compliance are needed.© RSNA, 2019Keywords: Abdomen/GI, Cirrhosis, Liver, MR-Imaging, Oncology, ScreeningSupplemental material is available for this article.

Molecular and histological correlations in liver cancer

Hepatocellular carcinoma (HCC) is a highly heterogeneous cancer, both at the molecular and histological level. High-throughput sequencing and gene expression profiling have identified distinct transcriptomic subclasses and numerous recurrent genetic alterations; several HCC subtypes characterised by histological features have also been identified. HCC phenotype appears to be closely related to particular gene mutations, tumour subgroups and/or oncogenic pathways. Non-proliferative tumours display a well-differentiated phenotype. Among this molecular subgroup, CTNNB1-mutated HCCs constitute a homogeneous subtype, exhibiting cholestasis and microtrabecular and pseudoglandular architectural patterns. Another non-proliferative subtype has a gene expression pattern similar to that of mature hepatocytes (G4) and displays a steatohepatitic phenotype. In contrast, proliferative HCCs are most often poorly differentiated, and notably include tumours with progenitor features. A novel morphological variant of proliferative HCC - designated "macrotrabecular-massive" - was recently shown to be associated with angiogenesis activation and poor prognosis. Altogether, these findings may help to translate our knowledge of HCC biology into clinical practice, resulting in improved precision medicine for patients with this highly aggressive malignancy. This manuscript reviews the most recent data in this exciting field, discussing future directions and challenges.

Pathological variants of hepatocellular carcinoma on MRI: emphasis on histopathologic correlation

Hepatocellular carcinoma (HCC) is a unique tumor because it is one of the few cancers which can be treated based on imaging alone. Magnetic resonance imaging (MRI) carries higher sensitivity and specificity for the diagnosis of HCC than either computed tomography (CT) or ultrasound. MRI is imaging modality of choice for the evaluation of complex liver lesions and HCC because of its inherent ability to depict cellularity, fat, and hepatocyte composition with high soft tissue contrast. The imaging features of progressed HCC are well described. However, many HCC tumors do not demonstrate classical imaging features, posing a diagnostic dilemma to radiologists. Some of these can be attributed to variations in tumor biology and histology, which result in radiological features that differ from the typical progressed HCC. This pictorial review seeks to demonstrate the appearance of different variants of HCC on MRI imaging, in relation to their histopathologic features.

Gadoxetic acid-enhanced magnetic resonance imaging: Hepatocellular carcinoma and mimickers

Gadoxetic acid, a hepatocyte-specific magnetic resonance imaging (MRI) contrast agent, has emerged as an important tool for hepatocellular carcinoma (HCC) diagnosis. Gadoxetic acid-enhanced MRI is useful for the evaluation of early-stage HCC, diagnosis of HCC precursor lesions, and highly sensitive diagnosis of HCC. Furthermore, functional information provided by gadoxetic acid-enhanced MRI can aid in the characterization of focal liver lesions. For example, whereas lesions lack functioning hepatocytes appear hypointense in the hepatobiliary phase, preserved or enhanced expression of organic anion transporting polypeptides in some HCCs as well as focal nodular hyperplasia lead to hyperintensity in the hepatobiliary phase; and a targetoid appearance on transitional phase or hepatobiliary phase imaging can be helpful for identifying the histopathological composition of tumors. While gadoxetic acid-enhanced MRI may improve the sensitivity of HCC diagnosis and provide new insights into the characterization of focal liver lesions, there are many challenges associated with its use. This article reviews the pros and cons of HCC diagnosis with gadoxetic acid-enhanced MRI and discuss some clues in the radiological differentiation of HCC from HCC mimickers.

Dimensions of hepatocellular carcinoma phenotypic diversity

Hepatocellular carcinoma (HCC) is the 3^rd leading cause of cancer-related death worldwide. More than 80% of HCCs arise within chronic liver disease resulting from viral hepatitis, alcohol, hemochromatosis, obesity and metabolic syndrome or genotoxins. Projections based on Western lifestyle and its metabolic consequences anticipate a further increase in incidence, despite recent breakthroughs in the management of viral hepatitis. HCCs display high heterogeneity of molecular phenotypes, which challenges clinical management. However, emerging molecular classifications of HCCs have not yet formed a unified corpus translatable to the clinical practice. Thus, patient management is currently based upon tumor number, size, vascular invasion, performance status and functional liver reserve. Nonetheless, an impressive body of molecular evidence emerged within the last 20 years and is becoming increasingly available to medical practitioners and researchers in the form of repositories. Therefore, the aim this work is to review molecular data underlying HCC classifications and to organize this corpus into the major dimensions explaining HCC phenotypic diversity. Major efforts have been recently made worldwide toward a unifying “clinically-friendly” molecular landscape. As a result, a consensus emerges on three major dimensions explaining the HCC heterogeneity. In the first dimension, tumor cell proliferation and differentiation enabled allocation of HCCs to two major classes presenting profoundly different clinical aggressiveness. In the second dimension, HCC microenvironment and tumor immunity underlie recent therapeutic breakthroughs prolonging patients’ survival. In the third dimension, metabolic reprogramming, with the recent emergence of subclass-specific metabolic profiles, may lead to adaptive and combined therapeutic approaches. Therefore, here we review recent molecular evidence, their impact on tumor histopathological features and clinical behavior and highlight the remaining challenges to translate our cognitive corpus into patient diagnosis and allocation to therapeutic options.

Peri-tumoral hyperintensity on hepatobiliary phase of gadoxetic acid-enhanced MRI in hepatocellular carcinomas: correlation with peri-tumoral hyperplasia and its pathological features

PURPOSE

Peri-tumoral hyperintensity (P-hyperintensity) is occasionally seen in hepatocellular carcinoma (HCC) on the hepatobiliary (HB) phase of gadoxetic acid-enhanced MRI (EOB-MRI). A recent study reported peri-tumoral hyperplasia (P-hyperplasia) associated with over-expression of glutamine synthetase (GS) in HCC or metastatic carcinoma. The aim of this study was to analyze the correlation between P-hyperintensity on the HB phase and GS expression indicating P-hyperplasia and reveal its pathological features.

METHODS

Seventy-seven surgically resected HCCs from 68 patients were analyzed. The grade of P-hyperintensity on HB phase was divided according to the degree of the peri-tumoral hyperintense signal: grade 0 (no P-hyperintensity), grade 1 (less than 50% of the tumor border), grade 2 (50%-80%), grade 3 (80%-100%). Immunohistochemical staining for GS and organic anion transporter polypeptides (OATP)1B3 was performed. The relationships among P-hyperplasia (peri-tumoral GS expression) and OATP1B3 expression, P-hyperintensity, and pathological features of the tumor were analyzed.

RESULTS

Thirty-four HCCs were classified as P-hyperintensity grade 0, 29 HCCs as grade 1,10 nodules as grade 2, and 4 HCCs as grade 3. P-hyperplasia was observed in 3/34 (8.8%) P-hyperintensity grade 0, 16/29 (55.2%) grade 1, 9/10 (90%) grade 2, and 4/4 (100%) grade 3. The incidence of P-hyperplasia was significantly increased in P-hyperintensity grades 1-3 compared with grade 0 (p < 0.0001). Hepatocytes in all P-hyperplasia sites demonstrated definite OATP1B3 expression. Microscopic hepatic venous invasion was significantly increased in P-hyperintensity-positive HCCs compared with negative HCCs (p = 0.0017).

CONCLUSIONS

P-hyperintensity on HB phase in HCC may indicate p-hyperplasia with GS and OATP1B3 expression and a higher incidence of microscopic hepatic venous invasion.

Role of Wnt/β-catenin signaling in hepatocellular carcinoma, pathogenesis, and clinical significance

Hepatocellular carcinoma (HCC) is one of the most common primary hepatic malignancies and one of the fastest-growing causes of cancer-related mortality in the United States. The molecular basis of HCC carcinogenesis has not been clearly identified. Among the molecular signaling pathways implicated in the pathogenesis of HCC, the Wnt/β-catenin signaling pathway is one of the most frequently activated. A great effort is under way to clearly understand the role of this pathway in the pathogenesis of HCC and its role in the transition from chronic liver diseases, including viral hepatitis, to hepatocellular adenomas (HCAs) and HCCs and its targetability in novel therapies. In this article, we review the role of the β-catenin pathway in hepatocarcinogenesis and progression from chronic inflammation to HCC, the novel potential treatments targeting the pathway and its prognostic role in HCC patients, as well as the imaging features of HCC and their association with aberrant activation of the pathway.

Quantitative correlation between uptake of Gd-BOPTA on hepatobiliary phase and tumor molecular features in patients with benign hepatocellular lesions

PURPOSE

The purpose of our study was to correlate the quantitative analysis of benign hepatocellular tumor uptake on delayed hepatobiliary phase (HBP) imaging with the quantitative level of OATP expression.

METHODS

This single-center retrospective study, which took place between September 2009 and March 2015, included 20 consecutive patients with a proven pathologic and immunohistochemical (IHC) diagnosis of FNH or HCA, including quantification of the OATP expression. The patients underwent Gd-BOPTA-enhancement MRI, including an HBP. The analysis of HBP uptake was performed using the liver-to-lesion contrast enhancement ratio (LLCER). Mean LLCER and OATP expressions were compared between FNH and HCA, and the expression of OATP was correlated with the LLCER value.

RESULTS

Of the 23 benign hepatocellular tumors, 9 (39%) were FNH and 14 (61%) were HCA, including 6 inflammatory, 2 HNF1a inactivated, 3 β-catenin-mutated and 3 unclassified HCAs. On HBP, 100% of the FNH appeared hyper- or isointense, and 79% of the adenomas appeared hypointense. The mean OATP expression of FNH (46.67 ± 26.58%) was significantly higher than that of HCA (22.14 ± 30.74%) (p = 0.0273), and the mean LLCER of FNH (10.66 ± 7.403%) was significantly higher than that of HCA (-13.5 ± 12.25%) (p < 0.0001). The mean LLCER of β-catenin-mutated HCA was significantly higher than that of other HCAs (p = 0.011). Significant correlation was found between the OATP expression and LLCER values (r = 0.661; p = 0.001).

CONCLUSION

In benign hepatocellular tumors, the quantitative analysis of hepatobiliary contrast agent uptake on HBP is correlated with the level of OATP expression and could be used as an imaging biomarker of the molecular background of HCA and FNH.

KEY POINTS

• Gd-BOPTA uptake on HBP correlates with the OATP level in benign hepatocellular tumors • FNH and β-catenin-mutated HCA showed an increased lesion-to-liver contrast enhancement ratio (LLCER) • Increased LLCER may be explained by activation of the Wnt β-catenin pathway.

Diallyl Trisulfide inhibits breast cancer stem cells via suppression of Wnt/β-catenin pathway

Cancer stem cells (CSCs) play a central role in the development of breast cancer. The canonical Wnt/β-catenin signal pathway is critical for maintaining CSCs characteristics. Diallyl trisulfide (DATS), a natural organosulfur compound from the garlic, exhibits effective antitumor properties. However, the role of DATS in regulating breast CSCs activity and the underlying molecular mechanisms remain obscure. In the present study, we reported that DATS efficiently inhibited the viability of breast CSCs as evidenced by reducing turmorspheres formation, decreasing the expression of breast CSCs markers (CD44, ALDH1A1, Nanog, and Oct4), as well as inhibiting proliferation and inducing apoptosis. Furthermore, we showed that DATS downregulated the activity of Wnt/β-catenin pathway, while LiCl-triggered Wnt/β-catenin activation diminished DATS inhibition on breast CSCs. Taken together, our results illustrated that DATS suppressed breast CSCs through inhibiting Wnt/β-catenin pathway activation. These novel findings could provide new insights into the molecular mechanisms of breast CSCs regulation as well as its target intervention and might provide new strategies for preventing and treating breast cancers.

Gadoxetic acid-enhanced magnetic resonance imaging reflects co-activation of β-catenin and hepatocyte nuclear factor 4α in hepatocellular carcinoma

AIM

The aim of this study is to clarify the correlation of the co-activation of β-catenin and hepatocyte nuclear factor (HNF)4α with the findings of gadoxetic acid-enhanced magnetic resonance imaging (MRI), organic anion transporting polypeptide (OATP)1B3 expression, and histological findings in hepatocellular carcinoma (HCC).

METHODS

One hundred and ninety-six HCCs surgically resected from 174 patients were enrolled in this study. The HCCs were classified into four groups by immunohistochemical expression of β-catenin, glutamine synthetase (GS), and HNF4α: (i) β-catenin/GS (positive [+]) HNF4α (+); (ii) β-catenin/GS (+) HNF4α (negative [-]); (iii) β-catenin/GS (-) HNF4α (+); and (iv) β-catenin/GS (-) HNF4α (-). We compared the four groups in terms of the enhancement ratio on the hepatobiliary phase of gadoxetic acid-enhanced MRI, immunohistochemical organic anion transporter polypeptide (OATP)1B3 (a main uptake transporter of gadoxetic acid) expression and histological features, overall survival, and no recurrence survival. The Kruskal-Wallis test, Steel-Dwass multiple comparisons test, Fisher's exact test, and log-rank (Mantel-Cox) test were used for statistical analyses.

RESULTS

Enhancement ratio on gadoxetic acid-enhanced MRI in HCC with β-catenin/GS (+) HNF4α (+) was significantly higher than those of the other three groups (P < 0.001). The OATP1B3 grade was also significantly higher in HCC with β-catenin/GS (+) HNF4α (+) (P < 0.001). Hepatocellular carcinoma with β-catenin/GS (+) HNF4α (+) showed the highest differentiation grade as compared to the other groups (P < 0.004). There were no significant differences in portal vein invasion, macroscopic growth pattern, or prognosis analyses between the four groups.

CONCLUSION

Co-activation of β-catenin and HNF4α would promote OATP1B3 expression, and consequently higher enhancement ratio on gadoxetic acid-enhanced MRI and higher differentiation grade in HCC.

Human hepatocellular carcinomas with a periportal phenotype have the lowest potential for early recurrence after curative resection

Hepatocellular carcinomas (HCCs) exhibit a diversity of molecular phenotypes, raising major challenges in clinical management. HCCs detected by surveillance programs at an early stage are candidates for potentially curative therapies (local ablation, resection, or transplantation). In the long term, transplantation provides the lowest recurrence rates. Treatment allocation is based on tumor number, size, vascular invasion, performance status, functional liver reserve, and the prediction of early (<2 years) recurrence, which reflects the intrinsic aggressiveness of the tumor. Well-differentiated, potentially low-aggressiveness tumors form the heterogeneous molecular class of nonproliferative HCCs, characterized by an approximate 50% β-catenin mutation rate. To define the clinical, pathological, and molecular features and the outcome of nonproliferative HCCs, we constructed a 1,133-HCC transcriptomic metadata set and validated findings in a publically available 210-HCC RNA sequencing set. We show that nonproliferative HCCs preserve the zonation program that distributes metabolic functions along the portocentral axis in normal liver. More precisely, we identified two well-differentiated, nonproliferation subclasses, namely periportal-type (wild-type β-catenin) and perivenous-type (mutant β-catenin), which expressed negatively correlated gene networks. The new periportal-type subclass represented 29% of all HCCs; expressed a hepatocyte nuclear factor 4A-driven gene network, which was down-regulated in mouse hepatocyte nuclear factor 4A knockout mice; were early-stage tumors by Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program, and tumor-node-metastasis staging systems; had no macrovascular invasion; and showed the lowest metastasis-specific gene expression levels and TP53 mutation rates. Also, we identified an eight-gene periportal-type HCC signature, which was independently associated with the highest 2-year recurrence-free survival by multivariate analyses in two independent cohorts of 247 and 210 patients.

CONCLUSION

Well-differentiated HCCs display mutually exclusive periportal or perivenous zonation programs. Among all HCCs, periportal-type tumors have the lowest intrinsic potential for early recurrence after curative resection. (Hepatology 2017;66:1502-1518).

Histological subtypes of hepatocellular carcinoma are related to gene mutations and molecular tumour classification

BACKGROUND & AIMS

Our increasing understanding of hepatocellular carcinoma (HCC) biology holds promise for personalized care, however its translation into clinical practice requires a precise knowledge of its relationship to tumour phenotype.

METHODS

We aimed at investigating molecular-phenotypic correlations in a large series of HCC. To this purpose, 343 surgically resected HCC samples were investigated by pathological review, immunohistochemistry, gene expression profiling and sequencing.

RESULTS

CTNNB1 (40%) and TP53 (21%) mutations were mutually exclusive and defined two major groups of HCC characterized by distinct phenotypes. CTNNB1 mutated tumours were large (p=0.002), well-differentiated (p<0.001), cholestatic (p<0.001), with microtrabecular (p<0.001) and pseudoglandular (p<0.001) patterns and without inflammatory infiltrates (p<0.001). TP53 mutated tumours were poorly differentiated (p<0.001) with a compact pattern (p=0.02), multinucleated (p=0.01) and pleomorphic (p=0.02) cells and frequent vascular invasion (p=0.02). World Health Organization (WHO) classification of histological subtypes were also strongly related to molecular features. The scirrhous subtype was associated with TSC1/TSC2 mutations (p=0.005), epithelial-to-mesenchymal transition and a progenitor expression profile. The steatohepatitic subtype showed frequent IL-6/JAK/STAT activation without CTNNB1, TERT and TP53 pathway alterations (p=0.01). Pathological review identified a novel subtype, designated as "macrotrabecular-massive" associated with poor survival (p<0.001), high alpha-fetoprotein serum level (p=0.02), vascular invasion (p<0.001), TP53 mutations (p<0.001) and FGF19 amplifications (p=0.02), features also validated in The Cancer Genome Atlas (TCGA) data. Finally, integration of HCC pathological characteristics with its transcriptomic classification showed phenotypically distinct tumour subclasses closely related to G1-G6 subgroups.

CONCLUSION

HCC phenotypes are tightly associated with gene mutations and transcriptomic classification. These findings may help in translating our knowledge of HCC biology into clinical practice. Lay summary: HCC is a very heterogenous tumour, both at the pathological and molecular levels. We show here that HCC phenotype is tightly associated to its molecular alterations and underlying oncogenic pathways.

Effect of Disease Pathologies on Transporter Expression and Function

Transporters are important determinants of drug absorption, distribution, and excretion. The clinical relevance of drug transporters in drug disposition and toxicology depends on their localization in liver, kidney, and brain. There has been growing evidence regarding the importance of disease status on alterations in metabolizing enzymes and transporter proteins. This review focuses on uptake and efflux transporter proteins in liver, kidney, and brain and discusses mechanisms of altered transporter expression and function secondary to disease.

肝脏转运体表达和功能的变化对肝疾病的影响

转运体是药物吸收、分布、代谢和排泄的重要决定因素, 在肝脏表达尤为广泛. 肝脏转运体可以摄取大多数内源性物质、营养物质和外源性物质进入肝脏, 在肝脏内经过一系列的代谢转化, 最终将其外排入胆汁, 并由胆汁排到肝外. 越来越多的证据表明, 肝脏疾病状态下转运体的表达和功能会发生改变, 影响药物在体内的处置过程, 进而增加药物相互作用的可能性, 同时加大了疾病药物治疗的难度. 本文从肝脏摄取型和外排型转运体两方面出发, 针对肝脏转运体表达和功能的变化对肝疾病的影响作一综述.

Comparison of contrast-enhanced ultrasonograpy with Gd-EOB-DTPA-enhanced MRI in the diagnosis of liver metastasis from colorectal cancer

PURPOSE

To compare contrast-enhanced ultrasonography (CEUS) using Sonazoid with Gd-EOB-DTPA-enhanced MRI (EOB-MRI) in the diagnosis of liver metastases in patients with colorectal cancer.

METHODS

A total of 69 patients diagnosed with or suspected of having liver metastasis were enrolled. These hepatic lesions were diagnosed by histopathological examination after surgical resection or based on follow-up using various imaging modalities. The diagnostic accuracies of CEUS and EOB-MRI were compared.

RESULTS

One hundred thirty-three lesions were detected. Of these lesions, 109 were diagnosed as liver metastases. Of the 133 lesions, 90.2% were detected on CEUS, and 98.5% on EOB-MRI. One hundred nine lesions were diagnosed as liver metastasis. The areas under the receiver operating characteristic curve for diagnosis were 0.906 and 0.851 on CEUS and EOB-MRI, respectively (p = 0.41). Sensitivity, specificity, positive predictive value (PPV), negative predictive value, and overall accuracy were 90.8%, 84.5%, 97.1%, 67.1%, and 90.2%, respectively, for CEUS, and 95.4%, 70.8%, 93.7%, 77.3%, and 91%, respectively, for EOB-MRI.

CONCLUSIONS

CEUS has a higher specificity and PPV for the diagnosis of liver metastasis than EOB-MRI. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:138-144, 2017.