Molecularly targeted therapies for hepatocellular carcinoma: sorafenib as a stepping stone

Since sorafenib, a multikinase inhibitor targeting angiogenesis of hepatocellular carcinoma (HCC), demonstrated survival benefits in recent clinical trials, it has changed the treatment paradigm and become the standard first-line treatment for patients with advanced HCC. However, disease stabilization with sorafenib lasts a few months, possibly due to the development of resistance, and thus the survival advantage was modest, even in patients with preserved liver function. Furthermore, there is currently no biomarker for monitoring the response or resistance to sorafenib. Currently, various kinds of molecularly targeted agents have been developed and are being evaluated in clinical trials. There are several steps required to improve the outcome from sorafenib therapy. First, a reliable predictive and prognostic biomarker is urgently needed. Second, a compelling indication of sorafenib treatment for HCC needs more clinical studies and consensus. Third, the actual benefits of sorafenib to patients with advanced liver dysfunction should be clarified and a more effective strategy for targeted therapy needs to be developed, for example, using a combination of targeted agents acting on different pathways or different levels of a key pathway. Finally, sorafenib could be used with other treatment modalities, such as local ablation or transarterial chemoembolization, to synergize efficacy. Based on the successful introduction of sorafenib, future studies should focus on plans to further improve the outcome of HCC patients by overcoming resistance and maximizing the efficacy of molecularly targeted therapy.     

Systemic therapy of hepatocellular carcinoma:Current status and future perspectives

The management of hepatocellular carcinoma(HCC)has substantially changed in the past few decades,the introduction of novel therapies(such as sorafenib)have improved patient survival.Nevertheless,HCC remains the third most common cause of cancer-related deaths worldwide.Decision-making largely relies on evidencebased criteria,as showed in the US and European clinical practice guidelines,which endorse five therapeutic recommendations:resection;transplantation;radiofrequency ablation;chemoembolization;and sorafenib.Many molecularly targeted agents that inhibit angiogenesis,epidermal growth factor receptor,and mammalian target of rapamycin are at different stages of clinical development in advanced HCC.Future research should continue to unravel the mechanism of hepatocarcinogenesis and to identify key relevant molecular targets for therapeutic intervention.Identification and validation of potential surrogate and predictive biomarkers hold promise to individualize patient’s treatment to maximize clinical benefit and minimize the toxicity and cost of targeted agents.     

Genetic and epigenetic aspects of initiation and progression of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is a primary cancer of the liver that is predominant in developing countries and is responsible for nearly 600000 deaths each year worldwide. Similar to many other tumors, the development of HCC must be understood as a multistep process involving the accumulation of genetic and epigenetic alterations in regulatory genes, leading to the activation of oncogenes and the inactivation or loss of tumor suppressor genes. Extensive research over the past decade has identified a number of molecular biomarkers, including aberrant expression of HCCrelated genes and microRNAs. The challenge facing HCC research and clinical care at this time is to address the heterogeneity and complexity of these genetic and epigenetic alterations and to use this information to direct rational diagnosis and treatment strategies. The multikinase inhibitor sorafenib was the first molecularly targeted drug for HCC to show some extent of survival benefits in patients with advanced tumors. Although the results obtained using sorafenib support the importance of molecular therapies in the treatment of HCC, there is still room for improvement. In addition,no molecular markers for drug sensitivity, recurrence and prognosis are currently clinically available. In this review, we provide an overview of recently published articles addressing HCC-related genes and microRNAs to update what is currently known regarding genetic and epigenetic aspects of the pathogenesis of HCC and propose novel promising candidates for use as diagnostic and therapeutic targets in HCC.     

非编码RNA在索拉非尼治疗肝细胞癌耐药中的作用机制

索拉非尼作为晚期肝细胞癌的一线治疗药物,能够有效改善肝癌患者预后。但索拉非尼耐药已经成为影响肝细胞癌治疗效果的主要障碍。近年来研究发现,非编码RNA在肝细胞癌索拉非尼耐药中起着关键作用。总结了非编码RNA通过诱导肝癌细胞自噬、促进肝癌干细胞增殖、促进肝癌细胞上皮-间质转化过程、抑制肝癌细胞凋亡以及调节肝癌组织微环境来调节肝癌细胞对索拉非尼的敏感性。指出了非编码RNA调控肝细胞癌索拉非尼耐药的分子机制在克服耐药方面的潜在临床意义。     

Current chemotherapies for advanced hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) increases with the advancement of chronic liver diseases such as hepatitis C or B. The recurrence rate is very high and causes disease progression to an advanced stage. Recent development of molecularly targeted agents for the treatment of advanced HCC has dramatically changed the chemotherapies used for this disease. We summarize the current findings on several drugs that are commonly used for the treatment of advanced HCC including sorafenib and hepatic arterial infusion chemotherapies.     

Chemotherapy for advanced hepatocellular carcinoma in the sorafenib age

The kinase inhibitor sorafenib is the only systemic therapy proven to have a positive effect on survival of patients with advanced hepatocellular carcinoma(HCC).After development of sorafenib and its introduction as a therapeutic agent used in the clinic,several critical questions have been raised.Clinical parameters and biomarkers predicting sorafenib efficacy are the most important issues that need to be elucidated.Although it is difficult to know the responders in advance using conventional characteristics of patients,there are specific serum cytokines and/or gene amplification in tumor tissues that have been reported to predict efficacy of sorafenib.Risk and benefits of continuation of sorafenib beyond radiological progression is another issue to consider because no other standard therapy for advanced HCC as yet exists.In addition,effectiveness of the expanded application of sorafenib is still controversial,although a few studies have shed some light on combinational treatment with sorafenib for intermediate-stage HCC.Recently,over 50 relevant drugs have been developed and are currently under investigation.The efficacy of some of these drugs has been extensively examined,but none have demonstrated any superiority over sorafenib,so far.However,there are several drugs that have shown efficacy for treatment after sorafenib failure,and these are proceeding to further studies.To address these issues and questions,we have done extensive literature review and summarize the most current status of therapeutic application of sorafenib.     

Targeted systemic therapies for hepatocellular carcinoma: clinical perspectives, challenges and implications

Hepatocellular carcinoma(HCC) is a lethal disease in most patients,due to its aggressive course and a lack of effective systemic therapies for advanced disease.Surgical resection and liver transplantation remain the only curative options for a small subset of patients.Few patients with HCC are diagnosed early enough to be eligible for curative treatment.Angiogenesis inhibition is a natural therapeutic target for all solid tumors,but particularly for the highly vascularized HCC tumors.With the approval of the targeted agent sorafenib,there are now additional options for patients with HCC.Although sorafenib does produce some improvement in survival in HCC patients,the responses are not durable.In addition,there are significant dermatologic,gastrointestinal,and metabolic toxicities,and,as importantly,there is still limited knowledge of its usefulness in special subpopulations with HCC.Other angiogenesis inhibitors are in development to treat HCC both in the first-line setting and for use following sorafenib failure;the furthest in development is brivanib,a dual fibroblast growth factor pathway and vascular endothelial growth factor receptor inhibitor.Additional agents with antiangiogenic properties also in phase Ⅱ and Ⅲ development for the treatment of patients with HCC include bevacizumab,ramucirumab,ABT-869,everolimus and ARQ 197.     

Targeting receptor tyrosine kinases in gastric cancer

Molecularly targeted therapeutic agents are constantly being developed and have been shown to be effective in various clinical trials.One group of representative targeted oncogenic kinases,the receptor tyrosine kinases(RTKs),has been associated with gastric cancer development.Trastuzumab,an inhibitor of ERBB2,has been approved for the treatment of gastric cancer,although other receptor tyrosine kinases,such as epidermal growth factor receptor,vascular endothelial growth factor,platelet-derived growth factor receptor,c-Met,IGF-1R and fibroblast growth factor receptor 2,are also activated in gastric cancer.The promising results of the trastuzumab clinical trial for gastric cancer resulted in the approval of trastuzumab-based therapy as a first-line treatment for human epidermal growth factor receptor 2-positive patients.On the other hand,the trial examining bevacizumab in combination with conventional chemotherapy did not meet its primary goal of increasing the overall survival time of gastric cancer patients;however,a significantly higher response rate and a longer progression-free survival were observed in the bevacizumab arm of the trial.Other clinical trials,especially phaseⅢtrials that have tested drugs targeting RTKs,such as cetuximab,panitumumab,gefitinib,erlotinib,figitumumab,sorafenib,sunitinib and lapatinib,have shown that these drugs have modest effects against gastric cancer.This review summarizes the recent results from the clinical trials of molecularly targeted drugs and suggests that further improvements in the treatment of advanced gastric cancer can be achieved through the combination of conventional drugs with the new molecularly targeted therapies.     

Current and novel approaches in the pharmacological treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumours worldwide. The mortality-to-incidence ratio is up to 91.6% in many countries, representing the third leading cause of cancer-related deaths. Systemic drugs, including the multikinase inhibitors sorafenib and lenvatinib, are first-line drugs used in HCC treatment. Unfortunately, these therapies are ineffective in most cases due to late diagnosis and the development of tumour resistance. Thus, novel pharmacological alternatives are urgently needed. For instance, immune checkpoint inhibitors have provided new approaches targeting cells of the immune system. Furthermore, monoclonal antibodies against programmed cell death-1 have shown benefits in HCC patients. In addition, drug combinations, including first-line treatment and immunotherapy, as well as drug repurposing, are promising novel therapeutic alternatives. Here, we review the current and novel pharmacological approaches to fight HCC. Preclinical studies, as well as approved and ongoing clinical trials for liver cancer treatment, are discussed. The pharmacological opportunities analysed here should lead to significant improvement in HCC therapy.     

Chemotherapy for hepatocellular carcinoma: The present and the future

Hepatocellular carcinoma(HCC) is the most common primary tumor of the liver. Its relationship to chronic liver diseases, in particular cirrhosis, develops on a background of viral hepatitis, excessive alcohol intake or metabolic steatohepatitis, leads to a high incidence and prevalence of this neoplasia worldwide. Despite the spread of HCC, its treatment it's still a hard challenge, due to high rate of late diagnosis and to lack of therapeutic options for advanced disease. In fact radical surgery and liver transplantation, the most radical therapeutic approaches, are indicated only in case of early diagnosis. Even local therapies, such as transarterial chemoembolization, find limited indications, leading to an important problem regarding treatment of advanced disease. In this situation, until terminal HCC occurs, systemic therapy is the only possible approach, with sorafenib as the only standard treatment available. Anyway, the efficacy of this drug is limited and many efforts are necessary to understand who could benefit more with this treatment. Therefore, other molecules for a targeted therapy were evaluated, but only regorafenib showed promising results. Beside molecular target therapy, also cytotoxic drugs, in particular oxaliplatinand gemcitabine-based regimens, and immune-checkpoint inhibitors were tested with interesting results. The future of the treatment of this neoplasia is linked to our ability to understand its mechanisms of resistance and to find novel therapeutic targets, with the objective to purpose individualized approaches to patients affected by advanced HCC.     

Management of advanced hepatocellular carcinoma in the era of targeted therapy

Systemic chemotherapy has had a disappointing track record in the management of advanced hepatocellular carcinoma (HCC). Single‐agent doxorubicin produces a response rate of 10–15%, but without any survival benefit, and combination chemotherapy has also yielded unimpressive results. With recent advances in the knowledge of hepato‐carcinogenesis, there has been encouraging development in the systemic therapy of advanced HCC patients, and particularly in the targeted therapy of advanced HCC. Among the newly identified targets, exciting results have been shown in targeting the anti‐angiogenic pathway and the Raf/mitogen‐activated protein kinase pathways. Bevacizumab, both as a single agent and in combination with other agents, has shown initial encouraging activity in treating advanced HCC. More recently, single‐agent sorafenib, a putative multitargeted kinase inhibitor, has shown to prolong the overall survival of patients with advanced HCC in the pivotal phase III Sorafenib HCC Assessment Randomized Protocol (SHARP) and Oriental study. Currently, sorafenib is the only approved targeted therapy for patients with advanced HCC. In addition, however, promising early results have been reported for other molecular‐targeted drugs including erlotinib and sunitinib. Future progress seems likely to depend on using controlled clinical trials to optimize synergistic combination treatments.     

Mechanisms of resistance to sorafenib and the corresponding strategies in hepatocellular carcinoma

Sorafenib, the unique drug as first-line treatment for advanced hepatocellular carcinoma (HCC), has opened a window of hope after searching for effective agents to combat HCC for decades. However, the overall outcomes are far from satisfactory. One of the explanations is the genetic heterogeneity of HCC, which has led to identifying predictive biomarkers for primary resistance to sorafenib, and then applying the concept of personalized medicine, or seeking therapeutic strategies such as combining sorafenib with other anticancer agents. Some of the combinations have demonstrated a better effectiveness than sorafenib alone, with good tolerance. The acquired resistance to sorafenib has also drawn attention. As a multikinase inhibitor, sorafenib targets several cellular signaling pathways but simultaneously or sequentially the addiction switches and compensatory pathways are activated. Several mechanisms are involved in the acquired resistance to sorafenib, such as crosstalks involving PI3K/Akt and JAK-STAT pathways, hypoxia-inducible pathways, epithelial-mesenchymal transition, etc . Based on the investigated mechanisms,some other molecular targeted drugs have been applied as second-line treatment for treat HCC after the failure of sorafenib therapy and more are under evaluation in clinical trials. However, the exact mechanisms accounting for sorafenib resistance remains unclear. Further investigation on the crosstalk and relationship of associated pathways will better our understanding of the mechanisms and help to find effective strategies for overcoming sorafenib resistance in HCC.     

Molecular targeted therapy for hepatocellular carcinoma:Current and future

Hepatocellular carcinoma(HCC)is one of the most frequent tumors worldwide.The majority of HCC cases occur in patients with chronic liver disease.Despite regular surveillance to detect small HCC in these patients,HCC is often diagnosed at an advanced stage.Because HCC is highly resistant to conventional systemic therapies,the prognosis for advanced HCC patients remains poor.The introduction of sorafenib as the standard systemic therapy has unveiled a new direction for future research regarding HCC treatment.However,given the limited efficacy of the drug,a need exists to look beyond sorafenib.Many molecular targeted agents that inhibit different pathways involved in hepatocarcinogenesis are under various phases of clinical development,and novel targets are being assessed in HCC.This review aims to summarize the efforts to target molecular components of the signaling pathways that are responsible for the development and progression of HCC and to discuss perspectives on the future direction of research.     

Current status and future prospects of chemotherapy for advanced hepatocellular carcinoma

Sorafenib is the only drug that demonstrates a survival benefit for advanced hepatocellular carcinoma (HCC). However, the therapeutic effect of sorafenib is limited, so development of a more effective treatment method and second-line treatments is needed. Since the advent of sorafenib, clinical studies have been conducted with a variety of drugs and treatment methods, mainly with molecular targeted therapy, but almost all trials have ended in failure. The reasons for the difficulty in the development of a novel drug or treatment method include the diversity of mechanisms in the carcinogenesis and development of HCC, as well as the presence of background liver diseases such as chronic hepatitis and cirrhosis. Trials with immune-checkpoint inhibitors, which have an entirely different anti-tumor mechanism from that of molecular targeted drugs or cytotoxic drugs, have recently begun. Based on the results to date, clinical trials are now being conducted with enriched target subjects. In the future, providing more individualized treatment approaches for patients with advanced HCC will be essential.     

Targeted therapies for hepatocellular carcinoma

Unlike most solid tumors, the incidence and mortality of hepatocellular carcinoma (HCC) have increased in the United States and Europe in the past decade. Most patients are diagnosed at advanced stages, so there is an urgent need for new systemic therapies. Sorafenib, a tyrosine kinase inhibitor (TKI), has shown clinical efficacy in patients with HCC. Studies in patients with lung, breast, or colorectal cancers have indicated that the genetic heterogeneity of cancer cells within a tumor affect its response to therapeutics designed to target specific molecules. When tumor progression requires alterations in specific oncogenes (oncogene addiction), drugs that selectively block their products might slow tumor growth. However, no specific oncogene addictions are yet known to be implicated in HCC progression, so it is important to improve our understanding of its molecular pathogenesis. There are currently many clinical trials evaluating TKIs for HCC, including those tested in combination with (eg, erlotinib) or compared with (eg, linifanib) sorafenib as a first-line therapy. For patients who do not respond or are intolerant to sorafenib, TKIs such as brivanib, everolimus, and monoclonal antibodies (eg, ramucirumab) are being tested as second-line therapies. There are early stage trials investigating the efficacy for up to 60 reagents for HCC. Together, these studies might change the management strategy for HCC, and combination therapies might be developed for patients with advanced HCC. Identification of oncogenes that mediate tumor progression, and trials that monitor their products as biomarkers, might lead to personalized therapy; reagents that interfere with signaling pathways required for HCC progression might be used to treat selected populations, and thereby maximize the efficacy and cost benefit.     

Adjuvant sorafenib in hepatocellular carcinoma: A cautionary comment of STORM trial

Recurrence rate of hepatocellular carcinoma (HCC) is very high even after curative surgery, and no postoperative therapies have been definitively shown to prevent HCC recurrence. Sorafenib is proved to be effective for advanced HCC by two large randomized controlled trials in 2008 and 2009. Therefore it stands to reason to expect that adjuvant sorafenib may improve post-surgery outcomes of patients with HCC. However, many questions still exist about the value of sorafenib for patients with HCC after surgery or transarterial chemoembolization. In this editorial, we complehensively reviewed the safety and efficacy of adjuvant sorafenib for patients with hepatocellar carcinoma after surgery or transarterial chemoembolization. We emphasized the positive and negative role of sorafenib.     

Supportive therapies for prevention of hepatocellular carcinoma recurrence and preservation of liver function

Hepatocellular carcinoma(HCC) is one of the deadliest cancers in the world and is associated with a high risk of recurrence. The development of a wide range of new therapies is therefore essential. In this study, from the perspective of supportive therapy for the prevention of HCC recurrence and preservation of liver function in HCC patients, we surveyed a variety of different therapeutic agents. We show that branched chain amino acids(BCAA) supplementation and late evening snack with BCAA, strategies that address issues of protein-energy malnutrition, are important for liver cirrhotic patients with HCC. For chemoprevention of HCC recurrence, we show that viral control after radical treatment is important. We also reviewed the therapeutic potential of antiviral drugs, sorafenib, peretinoin, iron chelators. Sorafenib is a kinase inhibitor and a standard therapy in the treatment of advanced HCC. Peretinoin is a vitamin A-like molecule that targets the retinoid nuclear receptor to induce apoptosis and inhibit tumor growth in HCC cells. Iron chelators, such as deferoxamine and deferasirox, act to prevent cancer cell growth. These chelators may have potential as combination therapies in conjunction with peretinoin. Finally, we review the potential inhibitory effect of bone marrow cells on hepatocarcinogenesis.     

challenges of advanced hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is an aggressive malignancy,resulting as the third cause of death by cancer each year. The management of patients with HCC is complex,as both the tumour stage and any underlying liver disease must be considered conjointly. Although surveillance by imaging,clinical and biochemical parameters is routinely performed,a lot of patients suffering from cirrhosis have an advanced stage HCC at the first diagnosis. Advanced stage HCC includes heterogeneous groups of patients with different clinical condition and radiological features and sorafenib is the only approved treatment according to Barcelona Clinic Liver Cancer. Since the introduction of sorafenib in clinical practice,several phase Ⅲ clinical trials have failed to demonstrate any superiority over sorafenib in the frontline setting. Locoregional therapies have also been tested as first line treatment,but their role in advanced HCC is still matter of debate. No single agent or combination therapies have been shown to impact outcomes after sorafenib failure. Therefore this review will focus on the range of experimental therapeutics for patients with advanced HCC and highlights the successes and failures of these treatments as well as areas for future development. Specifics such as dose limiting toxicity and safety profile in patients with liver dysfunction related to the underlying chronic liver disease should be considered when developing therapies in HCC. Finally,robust validated and reproducible surrogate end-points as well as predictive biomarkers should be defined in future randomized trials.     

Hepatic artery infusion chemotherapy for advanced hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the most common cancers worldwide. Surgery, percutaneous ablation and liver transplantation are the only curative treatment modalities for HCC. However, the majority of patients have unresectable disease at diagnosis. Therefore, effective treatment options for patients with advanced HCC are required. In advanced HCC, according to current international guidelines, sorafenib, a molecular targeted agent, is the standard treatment. However, alternative treatment modalities are required because of the low response rates and unsuitability of molecular agents in real practice. In various treatment modalities, mostly in Asia, hepatic arterial infusion chemotherapy(HAIC) has been applied to advanced HCC with a view to increasing the therapeutic efficacy. HAIC provides direct drug delivery into the tumor feeding vessels and also minimizes systemic toxicities through a greater first-pass effect in the liver. However, the sample sizes of studies on HAIC have been small and large randomized trials are still lacking. In this article, we describe the treatment efficacy of HAIC for advanced stage HCC and discuss future therapeutic possibilities.