Targeting the insulin-like growth factor pathway in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the third leading cause of cancer-related deaths worldwide. Only 30%-40% of the patients with HCC are eligible for curative treatments, which include surgical resection as the first option, liver transplantation and percutaneous ablation. Unfortunately, there is a high frequency of tumor recurrence after surgical resection and most HCC seem resistant to conventional chemotherapy and radiotherapy. Sorafenib, a multi-tyrosine kinase inhibitor, is the only chemotherapeutic option for patients with advanced hepatocellular carcinoma. Patients treated with Sorafenib have a significant increase in overall survival of about three months. Therefore, there is an urgent need to develop alternative treatments. Due to its role in cell growth and development, the insulin-like growth factor system is commonly deregulated in many cancers. Indeed, the insulin-like growth factor(IGF) axis has recently emerged as a potential target for hepatocellular carcinoma treatment. To this aim, several inhibitors of the pathway have been developed suchas monoclonal antibodies, small molecules, antisense oligonucleotides or small interfering RNAs. However recent studies suggest that, unlike most tumors, HCC development requires increased signaling through insulin growth factor Ⅱ rather than insulin growth factor Ⅰ. This may have great implications in the future treatment of HCC. This review summarizes the role of the IGF axis in liver carcinogenesis and the current status of the strategies designed to target the IGF-Ⅰ signaling pathway for hepatocellular carcinoma treatment.     

Growth factors as therapeutic targets in HCC

Despite various effective local treatments for hepatocellular carcinoma (HCC), some patients do not meet the treatment criteria because of extrahepatic metastases or macroscopic vascular invasion at the time of their diagnosis. Furthermore, many patients treated with successful local treatments develop recurrences after treatment. Although these patients receive systemic treatment including chemotherapy, HCC is generally recognized as a chemo-resistant tumor. Recently, new molecular targets have been confirmed and various targeted agents are now being investigated for the treatment of HCC. Epidermal growth factor receptor (EGFR) is frequently expressed in human hepatoma cells, and EGF may be one of the mitogens that are needed for the growth of hepatoma cells. HCC is generally hypervascular, and vascular endothelial growth factor (VEGF) promotes HCC development and metastasis. Various inhibitors targeting EGFR and/or VEGF, VEGF receptor (VEGFR) have been developed as treatments of HCC. In phase-II studies of these growth factor inhibitors, the response rates are relatively low; however, high rates of disease control, enabling a good time to progression, have been achieved. Recently, a randomized phase III trial of sorafenib versus placebo conducted in patients with advanced HCC demonstrated the beneficial effects of this drug on the time-to-progression and overall survival of the patients, and the drug could become established as the standard chemotherapeutic agent for advanced HCC. Further clinical trials using biologic agents are warranted to prolong the survival in HCC patients.     

Sorafenib suppresses postsurgical recurrence and metastasis of hepatocellular carcinoma in an orthotopic mouse model

Surgical resection is the first-line treatment for hepatocellular carcinoma (HCC) patients with well-preserved liver function. Nevertheless, the rate of postoperative recurrence at 5 years is as high as 70%, and this gravely jeopardizes the therapeutic outcome. Clearly, new approaches are needed for preventing the relapse of this deadly disease. Taking advantage of a luciferase-labeled orthotopic xenograft model of HCC, we examined the role of sorafenib, the first systemic drug approved for advanced HCC patients, in the prevention of HCC recurrence. We found that sorafenib suppressed the development of postsurgical intrahepatic recurrence and abdominal metastasis and consequently led to prolonged postoperative survival of mice in this model. Furthermore, hyperactivity of extracellular signal-regulated kinase signaling caused by elevated levels of growth factors associated with postoperative liver regeneration enhanced the sensitivity of HCC cells to sorafenib; this provides a plausible explanation for the observation that recurrent tumors are more responsive to growth inhibition by sorafenib. CONCLUSION: Our results strongly suggest that by effectively reducing postoperative recurrence, sorafenib has a potential application in early-stage HCC patients who have undergone hepatectomy with curative intention.     

Recent advances in multidisciplinary management of hepatocellular carcinoma

The incidence of hepatocellular carcinoma(HCC) is increasing, and it is currently the second leading cause of cancer-related death worldwide. Potentially curative treatment options for HCC include resection, transplantation, and percutaneous ablation, whereas palliative treatments include trans-arterial chemoembolization(TACE), radioembolization, and systemic treatments. Due to the diversity of available treatment options and patients’ presentations, a multidisciplinaryteam should decide clinical management of HCC, according to tumor characteristics and stage of liver disease. Potentially curative treatments are suitable for very-early- and early-stage HCC. However, the vast majority of HCC patients are diagnosed in later stages, where the tumor characteristics or progress of liver disease prevent curative interventions. For patients with intermediate-stage HCC, TACE and radioembolization improve survival and are being evaluated in addition to potentially curative therapies or with systemic targeted therapy. There is currently no effective systemic chemotherapy, immunologic, or hormonal therapy for HCC, and sorafenib is the only approved moleculartargeted treatment for advanced HCC. Other targeted agents are under investigation; trials comparing new agents in combination with sorafenib are ongoing. Combinations of systemic targeted therapies with local treatments are being evaluated for further improvements in HCC patient outcomes. This article provides an updated and comprehensive overview of the current standards and trends in the treatment of HCC.     

New molecular targets for hepatocellular carcinoma: the ErbB1 signaling system.

Hepatocellular carcinoma (HCC) is a major cause of cancer-related deaths. This malignancy is often diagnosed at an advanced state, when most potentially curative therapies are of limited efficacy. In addition, HCC is a type of tumor highly resistant to available chemotherapeutic agents, which leaves HCC patients with no effective therapeutic options and a poor prognosis. From a molecular perspective, HCC is a heterogeneous type of tumor. However, in most cases, HCC emerges on a background of persistent liver injury, inflammation and hepatocellular proliferation, which is characteristic of chronic hepatitis and cirrhosis. Recent studies have revealed that dysregulation of a limited number of growth and survival-related pathways can play a key role in HCC development. The epidermal growth factor receptor (ErbB1) can be bound and activated by a broad family of ligands, and can also engage in extensive cross talk with other signaling pathways. This system is considered as an important defense mechanism for the liver during acute tissue injury; however, accumulating evidences suggest that its chronic stimulation can participate in the neoplastic conversion of the liver. Agents that target the ErbB1 receptor have shown antineoplastic activity in other types of tumors, but their efficacy either alone or in combination with other compounds has just started to be tested in experimental and human HCC. Here, we review the evidences that support the involvement of the ErbB1 in HCC development and that provide a rationale for ErbB1 targeting in HCC prevention and treatment.     

Complete remission of advanced hepatocellular carcinoma by radiofrequency ablation after sorafenib therapy

Sorafenib,a potent multikinase inhibitor,lead to a significant improvement in progression free survival and overall survival in patients with advanced hepatocellular carcinoma(HCC).Though sorafenib has proven its efficacy in advanced stage HCC,there are limitedreports on the role of sorafenib allowing for curative treatment by down-staging.We herein report a case of advanced HCC with vascular invasion,which showed treatment response by sorafenib therapy as to allow for radiofrequency ablation as curative treatment.The patient was followed-up for 6 mo without recurrence with continued sorafenib therapy.     

Hepatocellular carcinoma review:Current treatment,and evidence-based medicine

Hepatocellular carcinoma(HCC)is the fifth most common tumor worldwide.Multiple treatment options are available for HCC including curative resection,liver transplantation,radiofrequency ablation,trans-arterial chemoembolization,radioembolization and systemic targeted agent like sorafenib.The treatment of HCC depends on the tumor stage,patient performance status and liver function reserve and requires a multidisciplinary approach.In the past few years with significant advances in surgical treatments and locoregional therapies,the short-term survival of HCC has improved but the recurrent disease remains a big problem.The pathogenesis of HCC is a multistep and complex process,wherein angiogenesis plays an important role.For patients with advanced disease,sorafenib is the only approved therapy,but novel systemic molecular targeted agents and their combinations are emerging.This article provides an overview of treatment of early and advanced stage HCC based on our extensive review of relevant literature.     

Treatment for hepatocellular carcinoma in Japan over the last three decades: Our experience and published work review

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer‐related mortality worldwide. In the last few decades, there has been a marked increase in therapeutic options for HCC and epidemiological characteristics at HCC diagnosis have also significantly changed. With these changes and advances in medical technology and surveillance program for detecting earlier stage HCC, survival in patients with HCC has significantly improved. Especially, patients with liver cirrhosis are at high risk of HCC development, and regular surveillance could enable early detection of HCC and curative therapy, with potentially improved clinical outcome. However, unfortunately, only 20% of HCC patients are amenable to curative therapy (liver transplantation, surgical resection or ablative therapies). Locoregional therapies such as radiofrequency ablation, percutaneous ethanol injection, microwave coagulation therapy and transcatheter arterial chemoembolization play a key role in the management of unresectable HCC. Currently, molecular‐targeted agents such as sorafenib have emerged as a promising therapy for advanced HCC. The choice of the treatment modality depends on the size of the tumor, tumor location, anatomical considerations, number of tumors present and liver function. Furthermore, new promising therapies such as gene therapy and immunotherapy for HCC have emerged. Approaches to the HCC diagnosis and adequate management for patients with HCC are improving survival. Herein, we review changes of epidemiological characteristics, prognosis and therapies for HCC and refer to current knowledge for this malignancy based on our experience of approximately 4000 HCC cases over the last three decades.     

Future treatment option for hepatocellular carcinoma: a focus on brivanib

Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, is particularly prevalent in the Asia-Pacific region. Guidelines on the treatment of HCC in Japan come from both consensus-based and evidence-based treatment algorithms. However, patients with extensive liver damage and/or more advanced disease (major vascular invasion and/or extrahepatic spread) are currently ineligible for any treatment. Recent knowledge of hepatocarcinogenesis has led to the targeting of new pathways, particularly the angiogenic pathway, with a specific focus on the vascular endothelial growth factor receptor (VEGFR). Apparently the most studied systemic antiangiogenic agent for HCC is sorafenib. An updated version of the aforementioned treatment algorithms recommends sorafenib therapy for advanced HCC patients with Child-Pugh A liver function and extrahepatic spread or major vascular invasion. Moreover, sorafenib is recommended for use in HCC patients who are refractory or intolerant to transarterial chemoembolization (TACE) with well-preserved liver function (Child-Pugh A). However, one of the unresolved issues is anti-VEGF resistance. It is speculated that novel antiangiogenic agents that combine inhibition of other pathways such as fibroblast growth factor receptor signaling in addition to VEGFR signaling might provide a potential mechanism to overcome anti-VEGF resistance in HCC. Brivanib inhibits both VEGF and fibroblast growth factor receptor signaling. To further investigate the benefits of brivanib for advanced HCC, a broad-spectrum, global, phase III development plan, the Brivanib studies in HCC patients at RISK (BRISK) clinical program, has been initiated. Clinical benefits seen with brivanib in the first-line setting, and following the failure of sorafenib therapy, highlight the potential to improve the clinical course of patients with advanced HCC, and this agent may provide a novel therapeutic option for the growing population of patients for whom no other treatment choice exists.     

Immunotherapy for recurrent hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is presented frequently in late stages that are not amenable for curative treatment. Even for patients who can undergo resection for curative treatment of HCC, up to 50% recur. For patients who were not exposed to systemic therapy prior to recurrence, recurrence frequently cannot be subjected to curative therapy or local treatments. Such patients have several options of immunotherapy(IO). This includes programmed cell death protein 1(PD-1) and cytotoxic T-lymphocyte...     

Epigenetic regulation of insulin-like growth factor axis in hepatocellular carcinoma

The insulin-like growth factor (IGF) signaling pathway is an important pathway in the process of hepatocarcinogenesis, and the IGF network is clearly dysregulated in many cancers and developmental abnormalities. In hepatocellular carcinoma (HCC), only a minority of patients are eligible for curative treatments, such as tumor resection or liver transplant. Unfortunately, there is a high recurrence of HCC after surgical tumor removal. Recent research efforts have focused on targeting IGF axis members in an attempt to find therapeutic options for many health problems. In this review, we shed lights on the regulation of members of the IGF axis, mainly by microRNAs in HCC. MicroRNAs in HCC attempt to halt the aberrant expression of the IGF network, and a single microRNA can have multiple downstream targets in one or more signaling pathways. Targeting microRNAs is a relatively new approach for identifying an efficient radical cure for HCC.     

Hepatocellular carcinoma: From diagnosis to treatment

Hepatocellular carcinoma(HCC) is the sixth most prevalent malignancy worldwide and is a rising cause of cancer related mortality. Risk factors for HCC are well documented and effective surveillance and early diagnosis allow for curative therapies. The majority of HCC appears to be caused by cirrhosis from chronic hepatitis B and hepatitis C virus. Preventive strategies include vaccination programs and anti-viral treatments.Surveillance with ultrasonography detects early stage disease and improves survival rates. Many treatment options exist for individuals with HCC and are determined by stage of presentation. Liver transplantation is offered to patients who are within the Milan criteria and are not candidates for hepatic resection. In patients with advanced stage disease, sorafenib shows some survival benefit.     

Liver cancer: Targeted future options

Hepatocellular carcinoma(HCC)has a poor prognosis an d systemic chemotherapies have disappointing results.The increasing knowledge of the molecular biolog y of HCC has resulted in novel targets,with the vascular endothelial growth factor and epidermal growth factor receptor(EGFR)-related pathways being of special interest.New blood vessel formation(angiogenesis)is essential for the growth of solid tumors.Anti-angiogenic strategies have become an important therapeutic modality for solid tumors.Several agents targeting angiogenesis-related pathways have entered clinical trials or have been already approved for the treatment of solid tumors.These include monoclonal antibodies,receptor tyrosine kinase inhibitors and immunomodulatory drugs.HCC is a highly vascular tumor,and angiogenesis is be-lieved to play an important role in its development and progression.This review summarizes recent advances in the basic understanding of the role of angiogenesis in HCC as well as clinical trials with novel therapeutic approaches targeting angiogenesis and EGFR-related pathways.     

Signaling pathway and molecular-targeted therapy for hepatocellular carcinoma

In recent years, molecular-targeted agents have been used clinically to treat various malignant tumors. In May 2009, sorafenib (Nexavar?) was approved in Japan for 'unresectable hepatocellular carcinoma (HCC)', and was the first molecular-targeted agent for use in HCC. To date, sorafenib is the only molecular-targeted agent whose survival benefit has been demonstrated in two global phase III randomized controlled trials, and has now been approved worldwide. Phase III clinical trials of other molecular-targeted agents comparing them with sorafenib as first-line treatment agents are now ongoing. Those agents target the vascular endothelial growth factor, platelet-derived growth factor receptors, as well as target the epidermal growth factor receptor, insulin-like growth factor receptor and mammalian target of rapamycin, in addition to other molecules targeting other components of the signal transduction pathways. This review outlines the main pathways involved in the development and progression of HCC and the agents that target these pathways. Finally, current status and future perspective will also be discussed.     

Diagnostic and therapeutic management of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is an increasing health problem, representing the second cause of cancerrelated mortality worldwide. The major risk factorfor HCC is cirrhosis. In developing countries, viral hepatitis represent the major risk factor, whereas in developed countries, the epidemic of obesity, diabetes and nonalcoholic steatohepatitis contribute to the observed increase in HCC incidence. Cirrhotic patients are recommended to undergo HCC surveillance by abdominal ultrasounds at 6-mo intervals. The current diagnostic algorithms for HCC rely on typical radiological hallmarks in dynamic contrast-enhanced imaging, while the use of α-fetoprotein as an independent tool for HCC surveillance is not recommended by current guidelines due to its low sensitivity and specificity. Early diagnosis is crucial for curative treatments. Surgical resection, radiofrequency ablation and liver transplantation are considered the cornerstones of curative therapy, while for patients with more advanced HCC recommended options include sorafenib and trans-arterial chemoembolization. A multidisciplinary team, consisting of hepatologists, surgeons, radiologists, oncologists and pathologists, is fundamental for a correct management. In this paper, we review the diagnostic and therapeutic management of HCC, with a focus on the most recent evidences and recommendations from guidelines.     

Hepatozelluläres Karzinom

Hepatocellular carcinoma (HCC) constitutes one of the most frequent cancers worldwide and in 80-90% develops as a consequence of liver cirrhosis. The prognosis of patients with HCC is not only dependent on the tumor stage, but also on the liver function. Patients with early HCC without extrahepatic metastasis can be successfully treated by liver transplantation, tumor resection or percutaneous tumor ablation (e.g. ethanol injection or radiofrequency ablation). Meta-analyses have shown that transarterial chemoembolization (TACE) appears to be an effective treatment for more advanced tumors, at least for a subgroup of patients with good liver function. However, in approximately 50% of HCC patients these treatment options are not applicable or not effective, because they suffer from advanced tumors and/or impaired liver function. Recently a randomized placebo controlled phase III study showed that the multikinase inhibitor sorafenib significantly improves survival of patients with advanced HCC and good liver function (child A). As a consequence of this study sorafenib is now available for effective systemic treatment of patients with advanced HCC.     

Das hepatozelluläre Karzinom

Hepatocellular cancer (HCC) is the most common cause of death among patients with liver cirrhosis. Screening programs for high-risk patients allow diagnosis at an early stage, when curative treatment options can be offered. Contrast-enhanced imaging modalities are used for diagnosis, with a typical finding in the respective imaging technique being sufficient to establish the diagnosis for lesions >2 cm. Depending on the imaging results, biopsy for histological confirmation of the diagnosis has to be considered for lesions 1–2 cm in diameter. Lesions <1 cm should be controlled after 3 months. In patients without chronic liver disease, histological confirmation is always required. According to stage-dependent treatment algorithms, surgical options are the primary treatment for early-stage disease (resection, orthotopic liver transplantation). In the case of contraindications, radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) can also be considered. The latter is the treatment modality of choice for intermediate-stage disease in which curative options are no longer available. Further ablative and radiological interventional therapy modalities are under current evaluation in clinical studies, also in combination with systemic therapies. For advanced-stage disease in patients with good liver function, systemic therapy with sorafenib is indicated. Further targeted therapies are currently not available. Data of a phase-III trial that has been recently published as abstract confirm the efficacy of Regorafenib as second line treatment. Additionally new data from international multicentric genome sequencing projects suggest further promising therapeutic targets. An effect of sorafenib in an adjuvant setting could not be confirmed.     

Effective treatment strategies other than sorafenib for the patients with advanced hepatocellular carcinoma invading portal vein

Patients with hepatocellular carcinoma(HCC) accompanying portal vein tumor thrombosis(PVTT) have relatively few therapeutic options and an extremely poor prognosis. These patients are classified into barcelonaclinic liver cancer stage C and sorafenib is suggested as the standard therapy of care. However, overall survival(OS) gain from sorafenib is unsatisfactory and better treatment modalities are urgently required. Therefore, we critically appraised recent data for the various treatment strategies for patients with HCC accompanying PVTT. In suitable patients, even surgical resection can be considered a potentially curative strategy. Transarterial chemoembolization(TACE) can be performed effectively and safely in a carefully chosen population of patients with reserved liver function and sufficient collateral blood flow nearby the blocked portal vein. A recent metaanalysis demonstrated that TACE achieved a substantial improvement of OS in HCC patients accompanying PVTT compared with best supportive care. In addition, transarterial radioembolization(TARE) using yttrium-90 microspheres achieves quality-of-life advantages and is as effective as TACE. A large proportion of HCC patients accompanying PVTT are considered to be proper for TARE. Moreover, TACE or TARE achieved comparable outcomes to sorafenib in recent studies and it was also reported that the combination of radiotherapy with TACE achieved a survival gain compared to sorafenib in HCC patients accompanying PVTT. Surgical resectionbased multimodal treatments, transarterial approaches including TACE and TARE, and TACE-based appropriate combination strategies may improve OS of HCC patients accompanying PVTT.     

Treatment of hepatocellular carcinoma: Steps forward but still a long way to go

Hepatocellular carcinoma(HCC) is the fifth most common malignancy and the third cause of tumor associated deaths worldwide. HCC incidence rates are increasing in many parts of the world including developing and developed countries. Potentially curative treatments for HCC are resection and liver transplantation, but these are only suitable for patients with small tumors, meeting strict pre-defined criteria, or well-compensated liver disease. Early diagnosis of HCCcan be achieved by surveillance of at-risk populations. For patients with non-resectable disease treatments modalities include loco-ablative and systemic therapies. In this review we focus on treatment options in HCC and their allocation. Although significant research is in progress, to this date, the results are unsatisfactory with limited long-term survival. In the fight against this deadly disease, there is still a long way to go.