Telomerase reverse transcriptase mutations in plasma DNA in patients with hepatocellular carcinoma or cirrhosis: Prevalence and risk factors

Serum exosome-derived ALDH1A1 can greatly predict the prognosis of patients with hepatitis E virus-related acute liver failure

BACKGROUND

Despite the insights into the role of aldehyde dehydrogenase 1 family member A1 (ALDH1A1) in various liver diseases, the expression and its prognostic significance in patients with hepatitis E virus-related acute liver failure (HEV-ALF) remain unclear. This study delved into the assessment of serum exosome-derived ALDH1A1 expression and its prognostic implications for HEV-ALF patients.

METHODS

Between January 2018 and December 2023, a total of 226 individuals with acute hepatitis E (AHE) and 210 patients with HEV-ALF were recruited from member units of Chinese Consortium for the Study of Hepatitis E. According to the number of organ failure, we categorized 210 HEV-ALF patients into three groups: two organs failure (n = 131), three organs failure (n = 46), and more than three organs failure (n = 33). In addition, 200 health controls from Suzhou Municipal Hospital were included.

RESULTS

The levels of serum exosome-derived ALDH1A1 in HEV-ALF patients were significantly higher than those in AHE patients and health controls (both P < 0.05). Furthermore, the levels of serum exosome-derived ALDH1A1 were the highest in more than three organs failure group, followed by three organs failure group and two organs failure group (all P < 0.001). Moreover, serum exosome-derived ALDH1A1 was positively correlated with total bilirubin in HEV-ALF patients (r = 0.315, P < 0.001). The comparisons of serum exosome-derived ALDH1A1 levels in treatment response showed that serum exosome-derived ALDH1A1 levels were decreased in the improvement group, while increased in the fluctuation and deterioration groups (all P < 0.001). Moreover, serum exosome-derived ALDH1A1 was an independent risk factor for predicting the 30-day mortality (P < 0.001). Furthermore, the area under the receiver operating characteristic curve was 0.943, with the sensitivity of 94.87% and specificity of 87.72%, indicating the robust decision-making ability. However, no significant differences were found in serum exosome-derived ALDH1A1 levels between patients aged < 60 and ≥ 60 years old (P = 0.131).

CONCLUSIONS

Serum exosome-derived ALDH1A1 can greatly predict the prognosis of HEV-ALF patients.

Molecular and immune landscape of hepatocellular carcinoma to guide therapeutic decision-making

Liver cancer, primarily HCC, exhibits highly heterogeneous histological and molecular aberrations across tumors and within individual tumor nodules. Such intertumor and intratumor heterogeneities may lead to diversity in the natural history of disease progression and various clinical disparities across the patients. Recently developed multimodality, single-cell, and spatial omics profiling technologies have enabled interrogation of the intertumor/intratumor heterogeneity in the cancer cells and the tumor immune microenvironment. These features may influence the natural history and efficacy of emerging therapies targeting novel molecular and immune pathways, some of which had been deemed undruggable. Thus, comprehensive characterization of the heterogeneities at various levels may facilitate the discovery of biomarkers that enable personalized and rational treatment decisions, and optimize treatment efficacy while minimizing the risk of adverse effects. Such companion biomarkers will also refine HCC treatment algorithms across disease stages for cost-effective patient management by optimizing the allocation of limited medical resources. Despite this promise, the complexity of the intertumor/intratumor heterogeneity and ever-expanding inventory of therapeutic agents and regimens have made clinical evaluation and translation of biomarkers increasingly challenging. To address this issue, novel clinical trial designs have been proposed and incorporated into recent studies. In this review, we discuss the latest findings in the molecular and immune landscape of HCC for their potential and utility as biomarkers, the framework of evaluation and clinical application of predictive/prognostic biomarkers, and ongoing biomarker-guided therapeutic clinical trials. These new developments may revolutionize patient care and substantially impact the still dismal HCC mortality.

Novel biomarkers for monitoring and management of hepatocellular carcinoma

Due to current challenges in the early detection, less than 40% of individuals diagnosed with hepatocellular carcinoma (HCC) are viable candidates for surgical intervention. Therefore, validating and launching of a novel precise diagnostic approach is essential for early diagnosis. Based on developing evidence using circulating tumor cells and their derivatives, circulating miRNAs, and extracellular vesicles (EVs), liquid biopsy may offer a reliable platform for the HCC's early diagnosis. Each liquid biopsy analyte may provide significant areas for diagnosis, prognostic assessment, and treatment monitoring of HCC patients depending on its kind, sensitivity, and specificity. The current review addresses potential clinical applications, current research, and future developments for liquid biopsy in HCC management.

Developments and current status of cell-free DNA in the early detection and management of hepatocellular carcinoma

Nowadays, hepatocellular carcinoma (HCC) is still a major threat to human health globally, with a disappointing prognosis. Regular monitoring of patients at high risk, utilizing abdominal ultrasonography combined with alpha-fetoprotein (AFP) serum analysis, enables the early detection of potentially treatable tumors. However, the approach has limitations due to its lack of sensitivity. Meanwhile, the current standard procedure for obtaining a tumor biopsy in cases of HCC is invasive and lacks the ability to assess the dynamic progression of cancer or account for tumor heterogeneity. Hence, there is a pressing need to develop non-invasive, highly sensitive biomarkers for HCC which can improve the accuracy of early diagnosis, assess treatment response and accurately predict the prognosis. In contrast to the conventional method of tissue biopsy, liquid biopsy offers a non-invasive approach that can be readily repeated. As a liquid biopsy approach, the analysis of cell-free DNA (cfDNA) offers real-time insights that can accurately portray the tumor burden and provide a comprehensive depiction of the genetic profile associated with HCC. In this review, we present a comprehensive summary of the recent research findings pertaining to the significance and potential practicality of cfDNA analysis in the early detection and effective management of HCC.

Circulating Tumor DNA Clinical Applications in Hepatocellular Carcinoma: Current Trends and Future Perspectives

BACKGROUND

Globally, liver cancers are the second most lethal malignancy after lung cancer (0.83 million deaths in 2020). Hepatocellular carcinoma (HCC) is the predominant type of primary liver cancer and is typically associated with liver fibrosis or cirrhosis. HCC diagnosis relies on histologic examination of surgical specimens or conventional tissue biopsy material. However, standard tissue biopsies are invasive and often do not accurately reflect the tumor heterogeneity. On the other hand, the use of liquid biopsies, represented mainly by circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs), has greatly increased in the past 2 decades. Indeed, liquid biopsies are a noninvasive, repeatable, and sensitive approach to studying tumor biology.

CONTENT

This review describes current clinical applications of ctDNA analysis in the management of patients with chronic liver disease, cirrhosis, and HCC. There is a substantial clinical potential of ctDNA, but interventional studies are still lacking for the moment.

SUMMARY

Detection of ctDNA in both asymptomatic individuals and high-risk patients (with chronic liver disease or cirrhosis) contributes to the early diagnosis of HCC. ctDNA analysis also offer tremendous information on the tumor burden and on the risk of early recurrence. The implementation of ctDNA analysis, in association with classical tumor markers (e.g., alpha-fetoprotein), may improve (a) HCC screening in high-risk patients, (b) stratification of the recurrence risk after surgery, and (c) prognosis evaluation of patients with HCC.

Is Cell-Free DNA Testing in Hepatocellular Carcinoma Ready for Prime Time?

Revamping the current biomarker landscape of hepatocellular carcinoma (HCC) with cell-free DNA (cfDNA) could improve overall outcomes. The use of commercially available cfDNA testing (also known as liquid biopsy) is limited by the low prevalence of targetable mutations and does not have any prognostic or predictive value. Thus, current cfDNA testing cannot be relied upon for perioperative risk stratification (POR), including early detection of recurrence, long-term surveillance, predicting outcomes, and treatment response. Prior evidence on cfDNA mutation profiling (non-specific detection or gene panel testing) suggests that it can be a reliable tool for POR and prognostication, but it still requires significant improvements. cfDNA methylation changes or epigenetic markers have not been explored extensively, but early studies have shown potential for it to be a prognostic biomarker tool. The predictive value of cfDNA (mutations and EM) to assist treatment selection (systemic therapy, immune-checkpoint inhibitor vs. tyrosine kinase inhibitor) and to monitor response to systemic and locoregional therapies should be a future area of focus. We highlighted the unmet needs in the HCC management and the current role of cfDNA testing in HCC in addressing them.

Refining Liver Biopsy in Hepatocellular Carcinoma: An In-Depth Exploration of Shifting Diagnostic and Therapeutic Applications

The field of hepatocellular carcinoma (HCC) has faced significant change on multiple levels in the past few years. The increasing emphasis on the various HCC phenotypes and the emergence of novel, specific therapies have slowly paved the way for a personalized approach to primary liver cancer. In this light, the role of percutaneous liver biopsy of focal lesions has shifted from a purely confirmatory method to a technique capable of providing an in-depth characterization of any nodule. Cancer subtype, gene expression, the mutational profile, and tissue biomarkers might soon become widely available through biopsy. However, indications, expectations, and techniques might suffer changes as the aim of the biopsy evolves from providing minimal proof of the disease to high-quality specimens for extensive analysis. Consequently, a revamped position of tissue biopsy is expected in HCC, following the reign of non-invasive imaging-only diagnosis. Moreover, given the advances in techniques that have recently reached the spotlight, such as liquid biopsy, concomitant use of all the available methods might gather just enough data to improve therapy selection and, ultimately, outcomes. The current review aims to discuss the changing role of liver biopsy and provide an evidence-based rationale for its use in the era of precision medicine in HCC.

Cell-Free DNA as a Surveillance Tool for Hepatocellular Carcinoma Patients after Liver Transplant

The liver is the world's sixth most common primary tumor site, responsible for approximately 5% of all cancers and over 8% of cancer-related deaths. Hepatocellular carcinoma (HCC) is the predominant type of liver cancer, accounting for approximately 75% of all primary liver tumors. A major therapeutic tool for this disease is liver transplantation. Two of the most significant issues in treating HCC are tumor recurrence and graft rejection. Currently, the detection and monitoring of HCC recurrence and graft rejection mainly consist of imaging methods, tissue biopsies, and alpha-fetoprotein (AFP) follow-up. However, they have limited accuracy and precision. One of the many possible components of cfDNA is circulating tumor DNA (ctDNA), which is cfDNA derived from tumor cells. Another important component in transplantation is donor-derived cfDNA (dd-cfDNA), derived from donor tissue. All the components of cfDNA can be analyzed in blood samples as liquid biopsies. These can play a role in determining prognosis, tumor recurrence, and graft rejection, assisting in an overall manner in clinical decision-making in the treatment of HCC.

HCC biomarkers - state of the old and outlook to future promising biomarkers and their potential in everyday clinical practice

Hepatocellular carcinoma (HCC) is one of the most common and deadly tumors worldwide. Management of HCC depends on reliable biomarkers for screening, diagnosis, and monitoring of the disease, as well as predicting response towards therapy and safety. To date, imaging has been the established standard technique in the diagnosis and follow-up of HCC. However, imaging techniques have their limitations, especially in the early detection of HCC. Therefore, there is an urgent need for reliable, non/minimal invasive biomarkers. To date, alpha-fetoprotein (AFP) is the only serum biomarker used in clinical practice for the management of HCC. However, AFP is of relatively rather low quality in terms of specificity and sensitivity. Liquid biopsies as a source for biomarkers have become the focus of clinical research. Our review highlights alternative biomarkers derived from liquid biopsies, including circulating tumor cells, proteins, circulating nucleic acids, and exosomes, and their potential for clinical application. Using defined combinations of different biomarkers will open new perspectives for diagnosing, treating, and monitoring HCC.

Liquid Biopsy Derived Circulating Tumor Cells and Circulating Tumor DNA as Novel Biomarkers in Hepatocellular Carcinoma

INTRODUCTION

The diagnosis of hepatocellular carcinoma (HCC) is made at a relatively advanced stage resulting in poor prognosis. Alpha-fetoprotein and liver ultrasound have limited accuracy as biomarkers in HCC. Liver biopsy provides information on tumor biology; however, it is invasive and holds high threat of tumor seeding. Thus, more accurate and less invasive approaches are needed.

AREAS COVERED

Highly sensitive liquid biopsy assays have made possible the detection and analysis of cells or organelles such as circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and tumor-derived exosomes. Here, we focus on CTCs and ctDNA components of liquid biopsy and their clinical application as diagnostic, prognostic and predictive biomarkers in HCC. Unlike tissue biopsy, liquid biopsy involves attaining a sample at several time frames in an easy and a non-invasive manner. They have been efficacious in detecting and classifying cancer, in predicting treatment response, in monitoring disease relapse and in identifying mechanisms of resistance to targeted therapies.

EXPERT OPINION

Although interesting and highly promising, liquid biopsy techniques still have many obstacles to overcome before their wide spread clinical application sees the light. It is expected that these techniques will be incorporated into traditional methodologies for better diagnostic, predictive and prognostic results.

The advanced development of molecular targeted therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common malignant tumors in China, severely threatens the life and health of patients. In recent years, precision medicine, clinical diagnoses, treatments, and innovative research have led to important breakthroughs in HCC care. The discovery of new biomarkers and the promotion of liquid biopsy technologies have greatly facilitated the early diagnosis and treatment of HCC. Progress in targeted therapy and immunotherapy has provided more choices for precise HCC treatment. Multiomics technologies, such as genomics, transcriptomics, and metabolomics, have enabled deeper understanding of the occurrence and development mechanisms, heterogeneity, and genetic mutation characteristics of HCC. The continued promotion and accurate typing of HCC, accurate guidance of treatment, and accurate prognostication have provided more treatment opportunities and prolonged survival timelines for patients with HCC. Innovative HCC research providing an in-depth understanding of the biological characteristics of HCC will be translated into accurate clinical practices for the diagnosis and treatment of HCC.

The advanced development of molecular targeted therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common malignant tumors in China, severely threatens the life and health of patients. In recent years, precision medicine, clinical diagnoses, treatments, and innovative research have led to important breakthroughs in HCC care. The discovery of new biomarkers and the promotion of liquid biopsy technologies have greatly facilitated the early diagnosis and treatment of HCC. Progress in targeted therapy and immunotherapy has provided more choices for precise HCC treatment. Multiomics technologies, such as genomics, transcriptomics, and metabolomics, have enabled deeper understanding of the occurrence and development mechanisms, heterogeneity, and genetic mutation characteristics of HCC. The continued promotion and accurate typing of HCC, accurate guidance of treatment, and accurate prognostication have provided more treatment opportunities and prolonged survival timelines for patients with HCC. Innovative HCC research providing an in-depth understanding of the biological characteristics of HCC will be translated into accurate clinical practices for the diagnosis and treatment of HCC.

Circulating Virus–Host Chimera DNAs in the Clinical Monitoring of Virus-Related Cancers

Simple Summary

Cell-free tumor DNA (ctDNA), the DNA released into circulation from tumors, is a promising tumor marker with versatile applications. The associations of the amount, somatic mutation frequency, and epigenetic modifications of ctDNA with the tumor burden, tumor behavior, and prognosis have been widely investigated in different types of tumors. However, there are still some challenging issues to be resolved before ctDNA can complement or even replace current serum tumor markers. We propose employing exogenous viral DNA integration that produces unique virus–host chimera DNA (vh-DNA) at junction sites. Cell-free vh-DNA may become a new biomarker because it overcomes background interference detection problems, takes advantage of virus tropism to localize the tumor, and acts as a universal marker for monitoring clonal expansion or tumor loads in tumors related to oncogenic viruses.

Abstract

The idea of using tumor-specific cell-free DNA (ctDNA) as a tumor biomarker has been widely tested and validated in various types of human cancers and different clinical settings. ctDNA can reflect the presence or size of tumors in a real-time manner and can enable longitudinal monitoring with minimal invasiveness, allowing it to be applied in treatment response assessment and recurrence monitoring for cancer therapies. However, tumor detection by ctDNA remains a great challenge due to the difficulty in enriching ctDNA from a large amount of homologous non-tumor cell-free DNA (cfDNA). Only ctDNA with nonhuman sequences (or rearrangements) can be selected from the background of cfDNA from nontumor DNAs. This is possible for several virus-related cancers, such as hepatitis B virus (HBV)-related HCC or human papillomavirus (HPV)-related cervical or head and neck cancers, which frequently harbor randomly integrated viral DNA. The junction fragments of the integrations, namely virus–host chimera DNA (vh-DNA), can represent the signatures of individual tumors and are released into the blood. Such ctDNA can be enriched by capture with virus-specific probes and therefore exploited as a circulating biomarker to track virus-related cancers in clinical settings. Here, we review virus integrations in virus-related cancers to evaluate the feasibility of vh-DNA as a cell-free tumor marker and update studies on the development of detection and applications. vh-DNA may be a solution to the development of specific markers to manage virus-related cancers in the future.

Circulating Tumor DNA: An Emerging Tool in Gastrointestinal Cancers

Circulating tumor DNA (ctDNA) is tumor-derived fragmented DNA in the bloodstream that has come from primary or metastatic cancer sites. Neoplasm-specific genetic and epigenetic abnormalities are increasingly being identified through liquid biopsy: a novel, minimally invasive technique used to isolate and analyze ctDNA in the peripheral circulation. Liquid biopsy and other emerging ctDNA technologies represent a paradigm shift in cancer diagnostics because they allow for the detection of minimal residual disease in patients with early-stage disease, improve risk stratification, capture tumor heterogeneity and genomic evolution, and enhance ctDNA-guided adjuvant and palliative cancer therapy. Moreover, ctDNA can be used to monitor the tumor response to neoadjuvant and postoperative therapy in patients with metastatic disease. Using clearance of ctDNA as an endpoint for escalation/de-escalation of adjuvant chemotherapy for patients considered to have high-risk disease has become an important area of research. The possibility of using ctDNA as a surrogate for treatment response-including for overall survival, progression-free survival, and disease-free survival-is an attractive concept; this surrogate will arguably reduce study duration and expedite the development of new therapies. In this review, we summarize the current evidence on the applications of ctDNA for the diagnosis and management of gastrointestinal tumors. Gastrointestinal cancers-including tumors of the esophagus, stomach, colon, liver, and pancreas-account for one-quarter of global cancer diagnoses and contribute to more than one-third of cancer-related deaths. Given the prevalence of gastrointestinal malignancies, ctDNA technology represents a powerful tool to reduce the global burden of disease.

Serum TERT C228T is an important predictor of non-viral liver cancer with fatty liver disease

Background

Molecular therapies and precision medicine are expected to be developed for liver cancer based on the diagnosis of DNA somatic alterations. However, it remains unclear whether TERT promoter mutation (TERT C228T) in serum cfDNA is useful for the diagnosis of liver cancer with non-viral fatty liver disease (FLD).

Methods

This retrospective cohort study examined 258 Japanese patients who had a confirmed diagnosis of primary liver cancer. We investigated the factors associated with TERT C228T and abnormal levels of liver cancer-specific tumor markers (AFP and PIVKAII) in serum samples.

Results

Multivariate analysis identified the etiology of FLD, vascular invasion, and non-cirrhosis as determinants of TERT C228T-positive liver cancer. Rates of positive TERT C228T in FLD were significantly higher than those of HBV and HCV. Conversely, rates of abnormal AFP in FLD were significantly lower than those of HBV and HCV. Viral suppression of HBV/HCV and alcohol intake did not affect TERT C228T, but AFP was significantly reduced by viral suppression. The rates of positive TERT C228T were significantly lower in HCV patients with viral clearance than those of FLD patients.

Conclusion

Our results highlight the importance of serum TERT C228T for the detection of non-viral FLD-related liver cancer. TERT C228T is a tumor marker that might not be influenced by inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12072-022-10313-y.

Utility of Cell-Free DNA Detection in Transplant Oncology

Simple Summary

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-liver transplant stages, and evaluate transplant rejection. The use of ctDNA to evaluate transplant rejection has been extensively studied in non-hepatocellular carcinoma (HCC) diseases. Emerging studies have also investigated the use of ctDNA detection in evaluating HCC tumor burden pre-and post-surgery as well as transplant rejection. However, extensive studies still need to be conducted to evaluate the role of ctDNA detection in the medical management of transplant oncology patients.

Abstract

Transplant oncology is an emerging field in cancer treatment that applies transplant medicine, surgery, and oncology to improve cancer patient survival and quality of life. A critical concept that must be addressed to ensure the successful application of transplant oncology to patient care is efficient monitoring of tumor burden pre-and post-transplant and transplant rejection. Cell-free DNA (cfDNA) detection has emerged as a vital tool in revolutionizing the management of cancer patients who undergo organ transplantation. The advances in cfDNA technology have provided options to perform a pre-transplant evaluation of minimal residual disease (MRD) and post-transplant evaluation of cancer recurrence and transplant rejection. This review aims to provide a comprehensive overview of the history and emergence of cfDNA technology, its applications to specifically monitor tumor burden at pre-and post-transplant stages, and evaluate transplant rejection.

Usefulness of Cell-Free Human Telomerase Reverse Transcriptase Mutant DNA Quantification in Blood for Predicting Hepatocellular Carcinoma Treatment Efficacy

Although the usefulness of liquid biopsy as a biomarker in the treatment of hepatocellular carcinoma (HCC) has been suggested, its usefulness in transcatheter arterial chemoembolization (TACE) or tyrosine kinase inhibitor (TKI) therapies has not been reported in detail. In this study, we investigated the clinical value of a cell-free (cf)DNA quantification system targeting the human telomerase reverse transcriptase (hTERT) promoter mutation in advanced HCC treatment. Plasma from 67 patients with advanced HCC, treated with TACE and TKI, was used for extraction of cfDNA. We defined cfDNA with the hTERT promoter C228T mutation as circulating mutant DNA (mutant DNA) and without the mutation as circulating wild-type DNA (wild-type DNA). We analyzed the changes in mutant and wild-type DNA levels during HCC treatment and examined the relationship between changes in the cfDNA level and the clinical course. Mutant DNA was detected in 73.1% (49/67) of the patients during HCC treatment. In univariate analysis, factors associated with detection of mutant DNA before treatment were the intrahepatic maximum tumor diameter (P = 0.015) and protein induced by vitamin K absence (PIVKAII) (P = 0.006). The degree of mutant DNA change after TACE was significantly correlated with tumor volume (P < 0.001), reflecting the treated tumor volume. Responders with peak cfDNA levels within 1 week of TKI initiation had significantly better progression-free survival than nonresponders (P = 0.004). Conclusion: Changes in blood hTERT promoter mutant DNA levels during TACE or TKI treatment indirectly reflect the amount of HCCs and are useful for predicting long-term treatment responses.

Clinical Application Value of Circulating Cell-free DNA in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and a leading cause of cancer-related deaths. Due to late diagnosis, early intrahepatic metastasis and nonresponse to systemic treatments, surgical resection and/or biopsy specimens remain the gold standard for disease staging, grading and clinical decision-making. Since only a small amount of tissue was obtained in a needle biopsy, the conventional tissue biopsy is unable to represent tumor heterogeneity in HCC. For this reason, it is imperative to find a new non-invasive and easily available diagnostic tool to detect HCC at an early stage and to monitor HCC recurrence. The past decade has witnessed considerable evolution in the development of liquid biopsy technologies with the emergence of next-generation sequencing. As a liquid biopsy approach, molecular analysis of cell-free DNA (cfDNA), characterized by noninvasiveness and real-time analysis, may accurately represent the tumor burden and comprehensively reflect genetic profile of HCC. Therefore, cfDNA may be used clinically as a predictive biomarker in early diagnosis, outcome assessment, and even molecular typing. In this review, we provide an update on the recent advances made in clinical applications of cfDNA in HCC.

Role of Circulating Tumor DNA in Gastrointestinal Cancers: Current Knowledge and Perspectives

Gastrointestinal (GI) cancers are major health burdens worldwide and biomarkers are needed to improve the management of these diseases along their evolution. Circulating tumor DNA (ctDNA) is a promising non-invasive blood and other bodily-fluid-based biomarker in cancer management that can help clinicians in various cases for the detection, diagnosis, prognosis, monitoring and personalization of treatment in digestive oncology. In addition to the well-studied prognostic role of ctDNA, the main real-world applications appear to be the assessment of minimal residual disease to further guide adjuvant therapy and predict relapse, but also the monitoring of clonal evolution to tailor treatments in metastatic setting. Other challenges such as predicting response to treatment including immune checkpoint inhibitors could also be among the potential applications of ctDNA. Although the level of advancement of ctDNA development in the different tumor localizations is still inhomogeneous, it might be now reliable enough to be soon used in clinical routine for colorectal cancers and shows promising results in other GI cancers.

Liquid Biopsy in Hepatocellular Carcinoma: Opportunities and Challenges for Immunotherapy

Hepatocellular carcinoma (HCC) is one of the deadliest cancer types worldwide. HCC is often diagnosed at a late stage when the therapeutic options are very limited. However, even at the earlier stages, the best treatment is liver transplantation, surgical resection or ablation. Surgical resection and ablation may carry a high risk of tumor recurrence. The recent introduction of immunotherapies resulted in clinical responses for a subgroup of patients, but there were still no effective predictive markers for response to immunotherapy or for recurrence after surgical therapy. The identification of biomarkers that could correlate and predict response or recurrence would require close monitoring of the patients throughout and after the completion of treatment. However, this would not be performed efficiently by repeated and invasive tissue biopsies. A better approach would be to use liquid biopsies including circulating tumor DNA (ctDNA), circulating RNA (e.g., microRNAs), circulating tumor cells (CTC) and extracellular vesicles (EVs) (e.g., exosomes) for disease monitoring in a non-invasive manner. In this review, we discuss the currently available technology that can enable the use of liquid biopsy as a diagnostic and prognostic tool. Moreover, we discuss the opportunities and challenges of the clinical application of liquid biopsy for immunotherapy of HCC.

Exploring the Interplay of Telomerase Reverse Transcriptase and β-Catenin in Hepatocellular Carcinoma

Simple Summary

Liver cancer is one of the deadliest human cancers. Two of the most common molecular aberrations in liver cancer are: (1) activating mutations in the gene encoding β-catenin (CTNNB1); and (2) promoter mutations in telomerase reverse transcriptase (TERT). Here, we review recent findings regarding the interplay between TERT and β-catenin in order to better understand their role in liver cancer.

Abstract

Hepatocellular carcinoma (HCC) is one of the deadliest human cancers. Activating mutations in the telomerase reverse transcriptase (TERT) promoter (TERTp) and CTNNB1 gene encoding β-catenin are widespread in HCC (~50% and ~30%, respectively). TERTp mutations are predicted to increase TERT transcription and telomerase activity. This review focuses on exploring the role of TERT and β-catenin in HCC and the current findings regarding their interplay. TERT can have contradictory effects on tumorigenesis via both its canonical and non-canonical functions. As a critical regulator of proliferation and differentiation in progenitor and stem cells, activated β-catenin drives HCC; however, inhibiting endogenous β-catenin can also have pro-tumor effects. Clinical studies revealed a significant concordance between TERTp and CTNNB1 mutations in HCC. In stem cells, TERT acts as a co-factor in β-catenin transcriptional complexes driving the expression of WNT/β-catenin target genes, and β-catenin can bind to the TERTp to drive its transcription. A few studies have examined potential interactions between TERT and β-catenin in HCC in vivo, and their results suggest that the coexpression of these two genes promotes hepatocarcinogenesis. Further studies are required with vertebrate models to better understand how TERT and β-catenin influence hepatocarcinogenesis.

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.

Somatic Mutations in Circulating Cell-Free DNA and Risk for Hepatocellular Carcinoma in Hispanics

Hispanics are disproportionally affected by liver fibrosis and hepatocellular carcinoma (HCC). Advanced liver fibrosis is a major risk factor for HCC development. We aimed at identifying somatic mutations in plasma cell-free DNA (cfDNA) of Hispanics with HCC and Hispanics with advanced liver fibrosis but no HCC. Targeted sequencing of over 262 cancer-associated genes identified nonsynonymous mutations in 22 of the 27 HCC patients. Mutations were detected in known HCC-associated genes (e.g., CTNNB1, TP53, NFE2L2, and ARID1A). No difference in cfDNA concentrations was observed between patients with mutations and those without detectable mutations. HCC patients with higher cfDNA concentrations or higher number of mutations had a shorter overall survival (p < 0.001 and p = 0.045). Nonsynonymous mutations were also identified in 17 of the 51 subjects with advanced liver fibrosis. KMT2C was the most commonly mutated gene. Nine genes were mutated in both subjects with advanced fibrosis and HCC patients. Again, no significant difference in cfDNA concentrations was observed between subjects with mutations and those without detectable mutations. Furthermore, higher cfDNA concentrations and higher number of mutations correlated with a death outcome in subjects with advanced fibrosis. In conclusion, cfDNA features are promising non-invasive markers for HCC risk prediction and overall survival.

Nano-Gold PCR in Detection of TERT Methylation and Its Correlation with Hepatitis B-Related Hepatocellular Carcinoma

This study aimed to introduce nano-gold PCR for detection of TERT methylation, and explore the correlation between TERT methylation and prognosis of hepatocellular carcinoma (HCC). From March 2016 to March 2018, 154 HBV carriers treated in our hospital were enrolled in the study and divided into HCC (68 cases), cirrhosis (45 cases) and chronic hepatitis (CH) groups (41 cases) based on clinical disease. HCC patients were further divided into methylation (30 cases) and non-methylation (38 cases) subgroup based on methylation status of the TERT. TERT methylation of HCC specimens were 44.12% and 35.24% by nano-PCR and conventional PCR, respectively. The TERT methylation and TERT expression in HCC specimens were higher than for cirrhosis and CH specimens. A significant positive correlation was observed between TERT methylation and TERT expression. AFP, Edmondson classification, tumor size, hilar lymph node and intrahepatic metastasis, and TNM staging in the methylation group were higher than in non-methylation group. Further, overall survival and progression-free survival were significantly shorter. Nano-gold PCR is more sensitive in detecting TERT methylation. As CHB progresses, TERT methylation increases. Greater methylation of the gene is associated with worse prognosis in HCC patients.

Liquid Biopsy in Hepatocellular Carcinoma: Where Are We Now?

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer related death worldwide. Diagnostic, prognostic, and predictive biomarkers are urgently needed in order to improve patient survival. Indeed, the most widely used biomarkers, such as alpha-fetoprotein (AFP), have limited accuracy as both diagnostic and prognostic tests. Liver biopsy provides an insight on the biology of the tumor, but it is an invasive procedure, not routinely used, and not representative of the whole neoplasia due to the demonstrated intra-tumoral heterogeneity. In recent years, liquid biopsy, defined as the molecular analysis of cancer by-products, released by the tumor in the bloodstream, emerged as an appealing source of new biomarkers. Several studies focused on evaluating extracellular vesicles, circulating tumor cells, cell-free DNA and non-coding RNA as novel reliable biomarkers. In this review, we aimed to provide a comprehensive overview on the most relevant available evidence on novel circulating biomarkers for early diagnosis, prognostic stratification, and therapeutic monitoring. Liquid biopsy seems to be a very promising instrument and, in the near future, some of these new non-invasive tools will probably change the clinical management of HCC patients.

Combined detection of circulating tumor cells, α-fetoprotein heterogene-3 and α-fetoprotein in the early diagnosis of HCC for the prediction of efficacy, prognosis, recurrence after microwave ablation

BACKGROUND

Early diagnosis can significantly improve treatment outcomes for hepatocellular carcinoma (HCC) patients. Currently, the dosage of serum alpha fetoprotein (AFP) is widely used in the diagnosis of HCC, but this biomarker has low specificity and may cause false positive or false negative results. Thus, it's necessary to find and validate other serum tumor markers that in association for AFP would increase the sensitivity and the specificity in the HCC diagnosis. This study investigated the predictive value of combined of AFP, AFP-L3, and Circulating tumor cells (CTCs).

METHODS

A total of 105 patients with HCC after microwave ablation (MWA) were divided into non recurrence group, recurrence group, good prognosis (CR + PR group, CR: Complete remission, PR: Partial remission) and poor prognosis (SD + PD group, SD: Stable, PD: Progression). ROC curve was used to analyze the short-term efficacy, prognosis and clinical value of combined detection of the three indicators in predicting postoperative recurrence of HCC patients with MWA.

RESULTS

The positive rate of serum CTCs, AFP-L3 and AFP combined detection in the diagnosis of HCC is higher than that of single index and two index detection. The AUC, sensitivity and specificity of serum CTCs, AFP-L3 and AFP combined detection was better than that of single index and two indexes in patients with HCC after MWA.

CONCLUSIONS

Combined detection of AFP, AFP-L3, and CTCs can effectively make up for the shortcomings of the detection with single and pairwise indicators. It can't only diagnose HCC in early, but also has a high clinical value of predicting the short-term efficacy, prognosis and recurrence of HCC patients after MWA treatment.

Post-treatment cell-free DNA as a predictive biomarker in molecular-targeted therapy of hepatocellular carcinoma

BACKGROUND

Liquid biopsies, particularly those involving circulating tumor DNA (ctDNA), are rapidly emerging as a non-invasive alternative to tumor biopsies. However, clinical applications of ctDNA analysis in hepatocellular carcinoma (HCC) have not been fully elucidated.

METHODS

We measured the amount of plasma-derived cell-free DNA (cfDNA) in HCC patients before (n = 100) and a few days after treatment (n = 87), including radiofrequency ablation, transarterial chemoembolization, and molecular-targeted agents (MTAs), and prospectively analyzed their associations with clinical parameters and prognosis. TERT promoter mutations in cfDNA were analyzed using droplet digital PCR. Furthermore, we performed a comprehensive mutational analysis of post-treatment cfDNA via targeted ultra-deep sequencing (22,000× coverage) in a panel of 275 cancer-related genes in selected patients.

RESULTS

Plasma cfDNA levels increased significantly according to HCC clinical stage, and a high cfDNA level was independently associated with a poor prognosis. TERT promoter mutations were detected in 45% of all cases but were not associated with any clinical characteristics. cfDNA levels increased significantly a few days after treatment, and a greater increase in post-treatment cfDNA levels was associated with a greater therapeutic response to MTAs. The detection rate of TERT mutations increased to 57% using post-treatment cfDNA, suggesting that the ctDNA was enriched. Targeted ultra-deep sequencing using post-treatment cfDNA after administering lenvatinib successfully detected various gene mutations and obtained promising results in lenvatinib-responsive cases.

CONCLUSIONS

Post-treatment cfDNA analysis may facilitate the construction of biomarkers for predicting MTA treatment effects.

Current status of ctDNA in precision oncology for hepatocellular carcinoma

The conventional method used to obtain a tumor biopsy for hepatocellular carcinoma (HCC) is invasive and does not evaluate dynamic cancer progression or assess tumor heterogeneity. It is thus imperative to create a novel non-invasive diagnostic technique for improvement in cancer screening, diagnosis, treatment selection, response assessment, and predicting prognosis for HCC. Circulating tumor DNA (ctDNA) is a non-invasive liquid biopsy method that reveals cancer-specific genetic and epigenetic aberrations. Owing to the development of technology in next-generation sequencing and PCR-based assays, the detection and quantification of ctDNA have greatly improved. In this publication, we provide an overview of current technologies used to detect ctDNA, the ctDNA markers utilized, and recent advances regarding the multiple clinical applications in the field of precision medicine for HCC.

Detection of oncogenic mutations in paired circulating tumor DNA and circulating tumor cells in patients with hepatocellular carcinoma

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In paired analysis CTCs were detected in 27% and ctDNA in 77% of HCC patients.

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The TERT promoter mutation C228T was present in all patients with one or more ctDNA mutations, or detectable CTCs.

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CtDNA (or TERT C228T) positivity was associated with macrovascular invasion and poor survival of advanced HCC patients.

Background and aims

Circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA) may be used for diagnostic or prognostic purposes in patients with hepatocellular carcinoma (HCC). We aim to determine whether CTCs or ctDNA are suitable to determine oncogenic mutations in HCC patients.

Methods

Twenty-six mostly advanced HCC patients were enrolled. 30 mL peripheral blood from each patient was obtained. CellSearch system was used for CTC detection. A sequencing panel covering 14 cancer-relevant genes was used to identify oncogenic mutations. TERT promoter C228T and C250T mutations were determined by droplet digital PCR.

Results

CTCs were detected in 27% (7/26) of subjects but at low numbers (median: 2 cells, range: 1–15 cells) and ctDNA in 77% (20/26) of patients. Mutations in ctDNA were identified in several genes: TERT promoter C228T (77%, 20/26), TP53 (23%, 6/26), CTNNB1 (12%, 3/26), PIK3CA (12%, 3/26) and NRAS (4%, 1/26). The TERT C228T mutation was present in all patients with one or more ctDNA mutations, or detectable CTCs. The TERT C228T and TP53 mutations detected in ctDNA were present at higher levels in matched primary HCC tumor tissue. The maximal variant allele frequency (VAF) of ctDNA was linearly correlated with largest tumor size and AFP level (Log10). CtDNA (or TERT C228T) positivity was associated with macrovascular invasion, and positivity of ctDNA (or TERT C228T) or CTCs (≥ 2) correlated with poor patient survival.

Conclusions

Oncogenic mutations could be detected in ctDNA from advanced HCC patients. CtDNA analysis may serve as a promising liquid biopsy to identify druggable mutations.

Cellular heterogeneity and plasticity in liver cancer

Hepatocarcinogenesis involves complex genetic and cellular dysregulations which drive the formation of hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, with extensive heterogeneity. In contrast to the broad spectrum of molecularly driven therapies available for defined patient groups in certain cancer types, unfortunately the treatment options for HCC are highly limited. The lack of representative molecular and cellular signatures in the heterogeneous HCC tumors that can effectively guide the choice of the most appropriate treatment among the patients unavoidably limits the treatment outcome. Advancement and wide availability of the next-generation sequencing technologies have empowered us to examine and capture not only the detailed genetic alterations of the HCC cells but also the precise composition of different cell types within the tumor microenvironment and their interactions with the HCC cells at an unprecedented level. The information generated has provided new insight and better defined the inter-patient intertumoral heterogeneity, intra-patient intratumoral heterogeneity as well as the plasticity of HCC cells. These collectively provide a robust scientific basis in guiding the development and use of targeted therapy and immunotherapy. To complement, liquid biopsy coupled with high-sensitivity sequencing could potentially be adopted as a more practical and safer approach to detect and reflect the tumor heterogeneity in HCC patients in guiding the choice of treatment and monitoring disease progression.

The Role of Liquid Biopsy in Hepatocellular Carcinoma Prognostication

Simple Summary

Hepatocellular carcinoma (HCC) is one of the deadliest cancer. Clinical guidelines for the management of HCC endorse algorithms deriving from clinical variables whose performances to prognosticate HCC is limited. Liquid biopsy is the molecular analysis of tumor by-products released into the bloodstream. It offers minimally-invasive access to circulating analytes like DNA, RNA, exosomes and cells. This technology demonstrated promising results for various applications in cancers, including prognostication. This review aimed to provide a comprehensive overview of the contribution of liquid biopsy in HCC prognostication. The results suggested that liquid biopsy may be a polyvalent and valuable tool to prognosticate HCC.

Abstract

Showing a steadily increasing cancer-related mortality, the epidemiological evolution of hepatocellular carcinoma (HCC) is concerning. Numerous strategies have attempted to prognosticate HCC but their performance is modest; this is partially due to the heterogeneous biology of this cancer. Current clinical guidelines endorse classifications and scores that use clinical variables, such as the Barcelona Clinic Liver Cancer (BCLC) classification. These algorithms are unlikely to fully recapitulate the genomic complexity of HCC. Integrating molecular readouts on a patient-basis, following a precision-medicine perspective, might be an option to refine prognostic systems. The limited access to HCC tissue samples is an important limitation to these approaches but it could be partially circumvented by using liquid biopsy. This concept consists of the molecular analysis of products derived from a solid tumor and released into biological fluids, mostly into the bloodstream. It offers an easy and minimally-invasive access to DNA, RNA, extracellular vesicles and cells that can be analyzed with next-generation sequencing (NGS) technologies. This review aims to investigate the potential contributions of liquid biopsy in HCC prognostication. The results identified prognostic values for each of the components of liquid biopsy, suggesting that this technology may help refine HCC prognostication.

TERT promoter mutated circulating tumor DNA as a biomarker for prognosis in hepatocellular carcinoma

BACKGROUND AND AIMS

Plasma circulating tumor DNA (ctDNA) with tumor-specific mutations is an attractive biomarker. The telomerase reverse transcriptase (TERT) C228T promoter mutation is the most prevalent tumor-associated mutation in hepatocellular carcinoma (HCC). We evaluated the presence and prognostic value of the TERT C228T mutation in plasma and tissue in a Danish HCC cohort.

METHODS

We analyzed ctDNA from 95 HCC patients and 45 liver cirrhotic patients without HCC for the TERT mutation using droplet digital polymerase chain reaction. We also analyzed DNA from the corresponding primary tumor tissues in 34 HCC patients.

RESULTS

The plasma TERT C228T mutation was detected in 42/95 HCC patients (44%) but in none of the non-HCC patients. The TERT mutation was detected in 23/34 tumor samples (68%). The TERT mutation was associated with increased mortality when detected in plasma (adjusted HR 2.16 (1.20-3.88), p = .010) but not in tumor tissue (adjusted HR 1.11 (0.35-3.56), p = .860). There was a positive correlation between the presence of the TERT mutation in plasma and an advanced TNM stage (p < .0001) and vascular invasion (p = .005). Analysis of the TERT mutation in plasma and tumor DNA from the same patient was concordant in 21/34 samples (62%; kappa value 0.31, p = .014). Non-concordance was associated with an early TNM stage.

CONCLUSION

The plasma TERT mutation was detected in 44% of HCC patients and in none of non-HCC cirrhotic patients; and was associated with increased mortality. We propose the TERT C228T mutation in ctDNA as a promising HCC biomarker for prognosis.

Cell-Free Virus-Host Chimera DNA From Hepatitis B Virus Integration Sites as a Circulating Biomarker of Hepatocellular Cancer

BACKGROUND AND AIMS

Early recurrence of hepatocellular carcinoma (HCC) after surgical resection compromises patient survival. Timely detection of HCC recurrence and its clonality is required to implement salvage therapies appropriately. This study examined the feasibility of virus-host chimera DNA (vh-DNA), generated from junctions of hepatitis B virus (HBV) integration in the HCC chromosome, as a circulating biomarker for this clinical setting.

APPROACH AND RESULTS

HBV integration in 50 patients with HBV-related HCC was determined by the Hybridization capture-based next-generation sequencing (NGS) platform. For individual HCC, the vh-DNA was quantified by specific droplet digital PCR (ddPCR) assay in plasma samples collected before and 2 months after surgery. HBV integrations were identified in 44 out of 50 patients with HBV-related HCC. Tumor-specific ddPCR was developed to measure the corresponding vh-DNA copy number in baseline plasma from each patient immediately before surgery. vh-DNA was detected in 43 patients (97.7%), and the levels correlated with the tumor sizes (detection limit at 1.5 cm). Among the plasma collected at 2 months after surgery, 10 cases (23.3%) still contained the same signature vh-DNA detected at baseline, indicating the presence of residual tumor cells. Nine of them (90%) experienced HCC recurrence within 1 year, supporting vh-DNA as an independent risk factor in predicting early recurrence. Analysis of circulating vh-DNA at recurrence further helped identify the clonal origin. A total of 81.8% of recurrences came from original HCC clones sharing the same plasma vh-DNA, whereas 18.2% were from de novo HCC.

CONCLUSIONS

vh-DNA was shown to be a circulating biomarker for detecting the tumor load in majority of patients with HBV-related HCC and aided in monitoring residual tumor and recurrence clonality after tumor resection.

Detection of TERT promoter mutation in serum cell-free DNA using wild-type blocking PCR combined with Sanger sequencing in hepatocellular carcinoma

Telomerase reverse transcriptase (TERT) promoter mutation is the most frequent genetic alteration in hepatocellular carcinoma (HCC). However, there is currently no suitable highly sensitive method that can detect such mutation using serum cell-free DNA (cfDNA). We analyzed somatic point mutations that substitute cytosine for thymidine at position 228 (C228T), as one of the hotspots of TERT promoter mutations, in serum cfDNA using a highly sensitive detection method of wild-type blocking polymerase chain reaction (WTB-PCR) combined with Sanger sequencing. In TERT promoter mutation sensitivity study, synthetic oligonucleotides were prepared to determine the lowest detection limit of the WTB-PCR, using serial dilutions of mutant-type (MT) DNA in the background of wild-type (WT) DNA. Using this technique, we conducted a longitudinal study in one patient who developed HCC during the follow-up and determined the relationship between HCC and TERT C228T in serum cfDNA. In the sensitivity study, the mutant peak at position 228 was detected at 0.7% or higher but was not detected at 0.6%. Thus, sequencing analysis of WTB-PCR product demonstrated the limit of detection in excess of 0.7% MT DNA in the background of WT DNA. One male patient with HCV-related cirrhosis developed HCC during the follow-up. TERT C228T was negative before the diagnosis of HCC, positive at the diagnosis of HCC and did not increase with advancement of malignancy. We developed a highly sensitive method for detection of TERT promoter mutation using WTB-PCR combined with Sanger sequencing and demonstrated its clinical usefulness in the measurement of TERT C228T in serum cfDNA. Larger studies are needed to confirm these results and establish the clinical utility of this new method.

Genomic Landscape of HCC

INTRODUCTION

Hepatocellular carcinoma (HCC) is a leading cause of cancer related mortality in the world and it has limited treatment options. Understanding the molecular drivers of HCC is important to develop novel biomarkers and therapeutics.

PURPOSE OF REVIEW

HCC arises in a complex background of chronic hepatitis, fibrosis and liver regeneration which lead to genomic changes. Here, we summarize studies that have expanded our understanding of the molecular landscape of HCC.

RECENT FINDINGS

Recent technological advances in next generation sequencing (NGS) have elucidated specific genetic and molecular programs involved in hepatocarcinogenesis. We summarize the major somatic mutations and epigenetic changes have been identified in NGS-based studies. We also describe promising molecular therapies and immunotherapies which target specific genetic and epigenetic molecular events.

SUMMARY

The genomic landscape of HCC is incredibly complex and heterogeneous. Promising new developments are helping us decipher the molecular drivers of HCC and leading to new therapies.

Utility of Liquid Biopsy Analysis in Detection of Hepatocellular Carcinoma, Determination of Prognosis, and Disease Monitoring: A Systematic Review

BACKGROUND & AIMS

Liquid biopsies, or blood samples, can be analyzed to detect circulating tumor cells (CTCs), cell-free DNA (cfDNA), and extracellular vesicles, which might identify patients with hepatocellular carcinoma (HCC) or help determine their prognoses. We performed a systematic review of studies of analyses of liquid biopsies from patients with HCC and their comparisons with other biomarkers.

METHODS

We performed a systematic review of original studies published before December 1, 2019. We included studies that compared liquid biopsies alone and in combination with other biomarkers for the detection of HCC, performed multivariate analyses of the accuracy of liquid biopsy analysis in determining patient prognoses, or evaluated the utility of liquid biopsy analysis in monitoring treatment response.

RESULTS

Our final analysis included 112 studies: 67 on detection, 46 on determining prognosis, and 25 on treatment monitoring or selection. Ten studies evaluated assays that characterized cfDNA for detection of HCC in combination with measurement of α-fetoprotein (AFP)-these studies found that the combined measurement of cfDNA and AFP more accurately identified patients with HCC than measurement of AFP alone. Six studies evaluated assays for extracellular vesicles and 2 studies evaluated assays for CTC in detection of HCC, with and without other biomarkers-most of these studies found that detection of CTCs or extracellular vesicles with AFP more accurately identified patients with HCC than measurement of AFP alone. Detection of CTCs before surgery was associated with HCC recurrence after resection in 13 of 14 studies; cfDNA and extracellular vesicles have been studied less frequently as prognostic factors. Changes in CTC numbers before vs after treatment more accurately identify patients with HCC recurrence than pretreatment counts alone, and measurements of cfDNA can identify patients with disease recurrence or progression before changes can be detected by imaging. We found little evidence that analyses of liquid biopsies can aid in the selection of treatment for HCC. Quality assessment showed risk of bias in studies of HCC detection and determination of prognosis.

CONCLUSIONS

In a systematic review of 112 studies of the accuracy of liquid biopsy analysis, we found that assays for CTCs and cfDNA might aid in determining patient prognoses and monitoring HCC, and assays for cfDNA might aid in HCC detection, but there is a risk of bias in these studies. Studies must be standardized before we can assess the clinical utility of liquid biopsy analysis in the detection and management of patients with HCC.

Clinical and Molecular Prediction of Hepatocellular Carcinoma Risk

Prediction of hepatocellular carcinoma (HCC) risk becomes increasingly important with recently emerging HCC-predisposing conditions, namely non-alcoholic fatty liver disease and cured hepatitis C virus infection. These etiologies are accompanied with a relatively low HCC incidence rate (~1% per year or less), while affecting a large patient population. Hepatitis B virus infection remains a major HCC risk factor, but a majority of the patients are now on antiviral therapy, which substantially lowers, but does not eliminate, HCC risk. Thus, it is critically important to identify a small subset of patients who have elevated likelihood of developing HCC, to optimize the allocation of limited HCC screening resources to those who need it most and enable cost-effective early HCC diagnosis to prolong patient survival. To date, numerous clinical-variable-based HCC risk scores have been developed for specific clinical contexts defined by liver disease etiology, severity, and other factors. In parallel, various molecular features have been reported as potential HCC risk biomarkers, utilizing both tissue and body-fluid specimens. Deep-learning-based risk modeling is an emerging strategy. Although none of them has been widely incorporated in clinical care of liver disease patients yet, some have been undergoing the process of validation and clinical development. In this review, these risk scores and biomarker candidates are overviewed, and strategic issues in their validation and clinical translation are discussed.

The use of minimally invasive biomarkers for the diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common cause of cancer-related deaths worldwide. Despite advances in systemic therapies, patient survival remains low due to late diagnosis and frequent underlying liver diseases. HCC diagnosis generally relies on imaging and liver tissue biopsy. Liver biopsy presents limitations because it is invasive, potentially risky for patients and it frequently misrepresents tumour heterogeneity. Recently, liquid biopsy has emerged as a way to monitor cancer progression in a non-invasive manner. Tumours shed content into the bloodstream, such as circulating tumour cells (CTCs), circulating nucleic acids, extracellular vesicles and proteins, that can be isolated from biological fluids of patients with HCC. These biomarkers provide knowledge regarding the genetic landscape of tumours and might be used for diagnostic or prognostic purposes. In this review, we summarize recent literature on circulating biomarkers for HCC, namely CTCs, circulating tumour DNA (ctDNA), RNA, extracellular vesicles and proteins, and their clinical relevance in HCC.

TERT Promoter Mutation in Serum Cell-Free DNA Is a Diagnostic Marker of Primary Hepatocellular Carcinoma in Patients with Nonalcoholic Fatty Liver Disease

INTRODUCTION

It remains unclear whether TERT promoter mutation (TERT C228T) in serum cell-free DNA (cfDNA) is useful for the diagnosis of hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

In this retrospective study, we analyzed the relationships between TERT C228T in serum cfDNA and levels of AFP and PIVKAII in 57 Japanese patients with histopathologically confirmed NAFLD background, consisting of 36 patients with HCC and 21 without HCC. We also examined the liver-related survival rate and HCC recurrence rate after the initial treatment for HCC. TERT C228T was detected using a highly sensitive method based on wild-type blocking PCR (detection limit in excess of 0.7% mutant-type DNA).

RESULTS

In all of the 57 patients, multivariate analysis identified TERT C228T positive as significant determinant of primary HCC. In the 36 patients with HCC, the percentage of patients positive for TERT C228T was 63.9%. The percentage of patients positive for TERT C228T with normal AFP and PIVKAII was 35.3%. The positive predictive value and specificity for prediction of BCLC stage 0 or A were both high. In 6 patients, TERT C228T was repeatedly negative during follow-up but became positive at the time of HCC diagnosis. Four patients who underwent HCC surgical resection had well-differentiated solitary HCC measuring <30 mm, and all were TERT C228T positive with normal AFP and PIVKAII. TERT C228T status had no influence on the cumulative liver-related survival rate and HCC recurrence rate.

CONCLUSIONS

Our results highlight the superiority of TERT C228T in serum cfDNA compared with AFP and PIVKAII in the early diagnosis of primary HCC in NAFLD patients.

Cancer-related genetic changes in multistep hepatocarcinogenesis and their correlation with imaging and histological findings

AIM

The landscape of cancer-related genetic aberrations in hepatocellular carcinoma (HCC) has gradually become clear through recent next-generation sequencing studies. However, it remains unclear how genetic aberrations correlate with imaging and histological findings.

METHODS

Using 117 formalin-fixed paraffin-embedded specimens of primary liver tumors, we undertook targeted next-generation sequencing of 50 cancer-related genes and digital polymerase chain reaction of hTERT. After classifying tumors into several imaging groups by hierarchal clustering with the information from gadoxetic acid enhanced magnetic resonance imaging, contrast-enhanced computed tomography, contrast-enhanced ultrasound, and diffusion-weighted imaging magnetic resonance imaging, the correlation between genetic aberrations and imaging and histology were investigated.

RESULTS

Most frequent mutations were hTERT (61.5%), followed by TP53 (42.7%), RB1 (24.8%), and CTNNB1 (18.8%). Liver tumors were classified into six imaging groups/grades, and the prevalence of hTERT mutations tended to increase with the advancement of imaging/histological grades (P = 0.026 and 0.13, respectively), whereas no such tendency was evident for TP53 mutation (P = 0.78 and 1.00, respectively). Focusing on the mutations in each tumor, although the variant frequency (VF) of hTERT did not change (P = 0.36 and 0.14, respectively) in association with imaging/histological grades, TP53 VF increased significantly (P = 0.004 and <0.001, respectively). In multivariate analysis, stage III or IV (hazard ratio, 3.64; P = 0.003), TP53 VF ≥ 50% (hazard ratio, 3.79; P = 0.020) was extracted as an independent risk for recurrence in primary HCC patients.

CONCLUSIONS

Increased prevalence of hTERT mutation and increased TP53 mutation VF are characteristic features of HCC progression, diagnosed with imaging/histological studies.

Liquid Biopsies in Hepatocellular Carcinoma: Are We Winning?

Hepatocellular carcinoma (HCC) represents the sixth most common cancer worldwide and the third most common cause of cancer-related death. One of the major problems faced by researchers and clinicians in this area is the lack of reliable disease biomarkers, which would allow for an earlier diagnosis, follow-up or prediction of treatment response, among others. In this regard, the “HCC circulome”, defined as the pool of circulating molecules in the bloodstream derived from the primary tumor, represents an appealing target, the so called liquid biopsy. Such molecules encompass circulating tumor proteins, circulating tumor cells (CTCs), extracellular vesicles (EVs), tumor-educated platelets (TEPs), and circulating tumor nucleic acids, namely circulating tumor DNA (ctDNA) and circulating tumor RNA (ctRNA). In this article, we summarize recent findings highlighting the promising role of liquid biopsies as novel potential biomarkers in HCC, emphasizing on its clinical performance.

Clinical significance of combined circulating TERT promoter mutations and miR-122 expression for screening HBV-related hepatocellular carcinoma

Telomerase reverse-transcriptase (TERT) gene promoter mutations in circulating cell-free DNA (cfDNA) as well as the levels of circulating microRNA-122 (miR-122) have been reported as potential noninvasive biomarkers for several. This study evaluates the diagnostic performance of potent biomarker-based panels composing of serological AFP, miR-122 and circulating TERT promoter mutations for screening HBV-related HCC. TERT promoter mutations (C228T and C250T) and miR-122 expression were assessed in the plasma samples from 249 patients with HBV-related liver diseases by nested PCR and qRT-PCR assays, respectively. The diagnostic values of TERT promoter mutations, miR-122 expression and biomarker-based panels were assessed by computation of the area under the curve (AUC). Nested-PCR assays were optimized to detect C228T and C250T mutations in TERT promoter with detection limit of 1%. The common hotspot C228T was observed in 22 HCC cases. The triple combinatory panel (AFP@TERT@miR-122) acquired the best diagnostic value to distinguish HCC from CHB (AUC = 0.98), LC (AUC = 0.88) or non-HCC (LC + CHB, AUC = 0.94) compared to the performance of double combinations or single biomarkers, respectively. Notably, among patients with AFP levels≤20 ng/μl, the double combination panel (TERT@miR-122) retains satisfactory diagnostic performance in discriminating HCC from the others (HCC vs. CHB, AUC = 0.96; HCC vs. LC, AUC = 0.88, HCC vs. non-HCC, AUC = 0.94). The triple combination panel AFP@TERT@miR-122 shows a better diagnostic performance for screening HCC in HBV patients, regardless of AFP levels. The newly established panels can be a potential application in clinical practice in Vietnamese setting.

Biomarkers for the Early Detection of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and the cancer with the fastest increase in mortality in the United States, with more than 39,000 cases and 29,000 deaths in 2018. As with many cancers, survival is significantly improved by early detection. The median survival of patients with early HCC is >60 months but <15 months when detected at an advanced stage. Surveillance of at-risk patients improves outcome, but fewer than 20% of those at risk for HCC receive surveillance, and current surveillance strategies have limited sensitivity and specificity. Ideally, blood-based biomarkers with adequate sensitivity or specificity would be available for early detection of HCC; however, the most commonly used biomarker for HCC, alpha-fetoprotein, has inadequate performance characteristics. There are several candidate serum proteomic, glycomic, and genetic markers that have gone through early stages of biomarker validation and have shown promise for the early detection of HCC, but these markers require validation in well-curated cohorts. Ongoing prospective cohort studies will permit retrospective longitudinal (phase III biomarker study) validation of biomarkers. In this review, we highlight promising candidate biomarkers and biomarker panels that have completed phase II evaluation but require further validation prior to clinical use.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Homeobox B5 suppression attenuates proliferation and elevates apoptosis in hepatoma cell lines through ERK/MDM2 signalling

Homeobox B5 (HOXB5), a member of the HOX gene family, is an important gene in tumourigenesis. However, its role in hepatocellular carcinoma (HCC) cell proliferation and apoptosis remains unclear. In this study, we investigated the role and regulation mechanism of HOXB5 in HCC cell lines Hep3B and LM6. The data indicated high expression of HOXB5 in HCC tissues and cell lines. In HCC cells, inhibition of HOXB5 by transfection with HOXB5 siRNA significantly constrained cell viability, and Bcl-2 levels, and it increased cell apoptosis, cytochrome c levels, BAX levels, and caspase-3 activity. On the contrary, HOXB5 overexpression increased proliferation and Bcl-2 levels but inhibited BAX levels and caspase-3 activity in these cells. HOXB5 downregulation attenuated activation of extracellular signal-regulated kinase (ERK) and expression of the murine double minute 2 (MDM2) oncogene. Incubation with the ERK activator, phorbol 12-myristate 13-acetate (40 μmol/L), for 12 hours reversed the effects of HOXB5 inhibition on MDM2 expression, cell proliferation, and apoptosis in HCC cells. Overall, this study demonstrated that HOXB5 inhibition regulated MDM2 expression by controlling ERK activation and that it modulated proliferation and apoptosis in HCC cells.

Detection of IDH1 and TERT promoter mutations with droplet digital PCR in diffuse gliomas

Mutations in isocitrate dehydrogenase (IDH) and telomerase reverse transcriptase promoter (TERTp) exert a far-reaching influence on clinicopathologic diagnosis and prognosis of glioma. Traditional approaches, such as Sanger sequencing and ARMS, lack sensitivity due to tumor heterogeneity and low tumor purity of glioma samples. Therefore, we propose a highly sensitive detection method for IDH1 and TERTp mutations based on ddPCR technology, named IDH1-TERT-mutation ddPCR (IT-ddPCR). We determined the IDH1 and TERTp mutations of 80 patients by Sanger sequencing, ARMS, and IT-ddPCR in parallel. We detected the TERTp mutations of 8 patients with probes by IT-ddPCR and Bio-Rad. IDH1-positive singles were detected in 56 cases by IT-ddPCR. TERTp-positive singles were detected in 50 cases by IT-ddPCR. There was a slight difference in total events, occupancy events, and C228T/C250T droplets between these two different probes. Regression analysis of the TERTp variant frequencies detected by probes of IT-ddPCR and Bio-Rad produced a slope of 1.0425 and a coefficient (R²) of 0.9231. We found that IT-ddPCR showed a higher sensitivity compared with Sanger sequencing and ARMS in the detection of IDH1 and TERTp mutations. There were no significant differences in variant frequencies of TERTp mutations between the two probes of IT-ddPCR and Bio-Rad. Thus, IT-ddPCR can be used to detect low-frequency mutation of IDH1 and TERTp in glioma.

Circulating Tumor DNA and Hepatocellular Carcinoma

There is a clear and unmet need for biomarkers in hepatocellular carcinoma (HCC). Circulating cell free deoxyribonucleic acid (cfDNA) is a fragmented DNA subtype, found in the blood circulation. Circulating tumor DNA (ctDNA) is the fraction of total cfDNA, which originates from the primary tumor or metastases in patients with cancer. Earlier studies reported that quantitative measurement cfDNA has diagnostic and prognostic role for HCC. More recently, improvement in next-generation sequencing technology and better understanding of genetic or epigenetic alteration of HCC have allowed comprehensive analysis of mutational and methylation landscape of ctDNA. Hotspot mutation panels and methylation panels have both shown promising performance. None of these tests have yet been validated in longitudinal cohorts for preclinical detection of HCC. In this article, the authors discuss the currently available ctDNA detection technologies, their diagnostic and prognostic performance in HCC, and future research directions.

Hepatocellular Carcinoma Risk Stratification by Genetic Profiling in Patients with Cirrhosis

Prediction of future hepatocellular carcinoma (HCC) risk in the sizable chronic liver disease population is an urgent unmet need to enable regular HCC screening for early detection. Germline deoxyribonucleic acid polymorphisms likely represent etiology-specific host factors that determine HCC susceptibility, including single nucleotide polymorphisms in EGF, IFNL3, MICA, and TLL1 in hepatitis C with or without active viral infection, and PNPLA3, TM6SF2, and MBOAT7 in metabolic liver diseases. Transcriptome-based prognostic liver signature in diseased liver tissue has been associated with long-term HCC risk in viral and metabolic etiologies. Transcriptomic signatures of hepatic injury and specific cell type such as aggregated lymphocytes also predict HCC development. Circulating factors such as proteins and their chemical modification, nucleotides, and metabolites may serve for less-invasive assessment of short- or long-term HCC risk. These biomarkers will enable individual HCC risk-based personalized clinical management for cost-effective early HCC detection and improvement of patient survival.