Postoperative use of the chemopreventive vitamin K2 analog in patients with hepatocellular carcinoma

Adjuvant Therapy for Hepatocellular Carcinoma After Curative Treatment: Several Unanswered Questions

Most patients with hepatocellular carcinoma (HCC) have a poor prognosis. Hepatectomy and local ablation are the main curative treatments for HCC. Nevertheless, the recurrence rate after hepatectomy or ablation is up to 70%, which seriously affects patient prognosis. Several adjuvant therapies have been explored to reduce postoperative recurrence. However, although a variety of adjuvant therapies have been shown to reduce the recurrence rate and improve overall survival, a standard consensus of national HCC guidelines for adjuvant treatment is lacking. Therefore, there are significant differences in the recommendations for adjuvant therapy for HCC between the Eastern and Western guidelines. A variety of adjuvant treatment methods, such as antiviral therapy, transarterial chemoembolization or traditional Chinese medicine, are recommended by the Chinese HCC guidelines. However, Western guidelines make few recommendations other than antiviral therapy. Adjuvant immune checkpoint inhibitors are recommended only in the recently updated American Association for the Study of Liver Diseases guidelines. This review summarized the existing adjuvant therapy options after curative hepatectomy or ablation and discusses several important dilemmas of adjuvant treatments.

Antitumor Activity of Metformin Combined with Locoregional Therapy for Liver Cancer: Evidence and Future Directions

This article aimed to examine the effect of metformin use on improving outcomes after liver-directed therapy in patients with HCC and identify future directions with the adjuvant use of and potential therapeutic agents that operate on similar mechanistic pathways. Databases were queried to identify pertinent articles on metformin's use as an anti-cancer agent in HCC. Eleven studies were included, with five pre-clinical and six clinical studies. The mean overall survival (OS) and progression-free survival were both higher in the locoregional therapy (LRT) + metformin-treated groups. The outcome variables, including local tumor recurrence rate, reduction in HCC tumor growth and size, tumor growth, proliferation, migration and invasion of HCC cells, HCC cell apoptosis, DNA damage, and cell cycle arrest, showed favorable outcomes in the LRT + metformin-treated groups compared with LRT alone. This systemic review provides a strong signal that metformin use can improve the tumor response after locoregional therapy. Well-controlled prospective trials will be needed to elucidate the potential antitumor effects of metformin and other mTOR inhibitors.

Vitamin K Contribution to DNA Damage—Advantage or Disadvantage? A Human Health Response

Vitamin K is the common name for a group of compounds recognized as essential for blood clotting. The group comprises phylloquinone (K1)—a 2-methyl-3-phytyl-1,4-naphthoquinone; menaquinone (K2, MK)—a group of compounds with an unsaturated side chain in position 3 of a different number of isoprene units and a 1,4-naphthoquinone group and menadione (K3, MD)—a group of synthetic, water-soluble compounds 2-methyl-1,4-naphthoquinone. However, recent epidemiological studies suggest that vitamin K has various benefits that go beyond blood coagulation processes. A dietary intake of K1 is inversely associated with the risk of pancreatic cancer, K2 has the potential to induce a differentiation in leukemia cells or apoptosis of various types of cancer cells, and K3 has a documented anti-cancer effect. A healthy diet rich in fruit and vegetables ensures an optimal supply of K1 and K2, though consumers often prefer supplements. Interestingly, the synthetic form of vitamin K—menadione—appears in the cell during the metabolism of phylloquinone and is a precursor of MK-4, a form of vitamin K2 inaccessible in food. With this in mind, the purpose of this review is to emphasize the importance of vitamin K as a micronutrient, which not only has a beneficial effect on blood clotting and the skeleton, but also reduces the risk of cancer and other pro-inflammatory diseases. A proper diet should be a basic and common preventive procedure, resulting in a healthier society and reduced burden on healthcare systems.

Advances in postoperative adjuvant therapy for primary liver cancer

Hepatocellular carcinoma (HCC) is a highly heterogeneous, invasive, and conventional chemotherapy-insensitive tumor with unique biological characteristics. The main methods for the radical treatment of HCC are surgical resection or liver transplantation. However, recurrence rates are as high as 50% and 70% at 3 and 5 years after liver resection, respectively, and even in Milan-eligible recipients, the recurrence rate is approximately 20% at 5 years after liver transplantation. Therefore, reducing the postoperative recurrence rate is key to improving the overall outcome of liver cancer. This review discusses the risk factors for recurrence in patients with HCC radical surgical resection and adjuvant treatment options that may reduce the risk of recurrence and improve overall survival, including local adjuvant therapy (e.g., transcatheter arterial chemoembolization), adjuvant systemic therapy (e.g., molecular targeted agents and immunotherapy), and other adjuvant therapies (e.g., antiviral and herbal therapy). Finally, potential research directions that may change the paradigm of adjuvant therapy for HCC are analyzed.

Exploring the Immune-Boosting Functions of Vitamins and Minerals as Nutritional Food Bioactive Compounds: A Comprehensive Review

Food components have long been recognized to play a fundamental role in the growth and development of the human body, conferring protective functionalities against foreign matter that can be severe public health problems. Micronutrients such as vitamins and minerals are essential to the human body, and individuals must meet their daily requirements through dietary sources. Micronutrients act as immunomodulators and protect the host immune response, thus preventing immune evasion by pathogenic organisms. Several experimental investigations have been undertaken to appraise the immunomodulatory functions of vitamins and minerals. Based on these experimental findings, this review describes the immune-boosting functionalities of micronutrients and the mechanisms of action through which these functions are mediated. Deficiencies of vitamins and minerals in plasma concentrations can lead to a reduction in the performance of the immune system functioning, representing a key contributor to unfavorable immunological states. This review provides a descriptive overview of the characteristics of the immune system and the utilization of micronutrients (vitamins and minerals) in preventative strategies designed to reduce morbidity and mortality among patients suffering from immune invasions or autoimmune disorders.

Adjuvant treatment strategy after curative resection for hepatocellular carcinoma

Hepatic resection represents the first-line treatment for patients with resectable hepatocellular carcinoma (HCC). However, the 5-year recurrence rates of HCC after surgery have been reported to range from 50% to 70%. In this review, we evaluated the available evidence for the efficiency of adjuvant treatments to prevent HCC recurrence after curative liver resection. Antiviral therapy has potential advantages in terms of reducing the recurrence rate and improving the overall survival (OS) and/or disease-free survival of patients with hepatitis-related HCC. Postoperative adjuvant transarterial chemoembolization can significantly reduce the intrahepatic recurrence rate and improve OS, especially for patients with a high risk of recurrence. The efficacy of molecular targeted drugs as an adjuvant therapy deserves further study. Adjuvant adoptive immunotherapy can significantly improve the clinical prognosis in the early stage. Randomized controlled trial (RCT) studies evaluating adjuvant immune checkpoint inhibitors are ongoing, and the results are highly expected. Adjuvant hepatic artery infusion chemotherapy might be beneficial in patients with vascular invasion. Huaier granule, a traditional Chinese medicine, has been proved to be effective in prolonging the recurrence-free survival and reducing extrahepatic recurrence. The efficiency of other adjuvant treatments needs to be further confirmed by large RCT studies.

Role of emerging vitamin K‑dependent proteins: Growth arrest‑specific protein 6, Gla‑rich protein and periostin (Review)

Vitamin K‑dependent proteins (VKDPs) are a group of proteins that need vitamin K to conduct carboxylation. Thus far, scholars have identified a total of 17 VKDPs in the human body. In this review, we summarize three important emerging VKDPs: Growth arrest‑specific protein 6 (Gas 6), Gla‑rich protein (GRP) and periostin in terms of their functions in physiological and pathological conditions. As examples, carboxylated Gas 6 and GRP effectively protect blood vessels from calcification, Gas 6 protects from acute kidney injury and is involved in chronic kidney disease, GRP contributes to bone homeostasis and delays the progression of osteoarthritis, and periostin is involved in all phases of fracture healing and assists myocardial regeneration in the early stages of myocardial infarction. However, periostin participates in the progression of cardiac fibrosis, idiopathic pulmonary fibrosis and airway remodeling of asthma. In addition, we discuss the relationship between vitamin K, VKDPs and cancer, and particularly the carboxylation state of VKDPs in cancer.

Updates and advancements in the management of hepatocellular carcinoma patients after hepatectomy

Introduction: The 5-year recurrence rate of hepatocellular carcinoma (HCC) after hepatic resection or local ablation is up to 70%. Adjuvant therapies to prevent HCC recurrence have been reported but are not currently recommended by EASL or AASLD guidelines. This review examined evidence from randomized controlled trials, meta-analyses and systematic reviews on the safety and efficacy of adjuvant therapies and chemotherapies in HCC patients after resection or local ablation.Areas covered: PubMed was searched through 15 June 2019. Available evidence was assessed based on the GRADE system.Expert commentary: Transarterial chemoembolization is the best adjuvant therapy for HCC patients at high risk of recurrence, antiviral therapy with nucleoside analogs is effective for preventing recurrence of HBV-related HCC, and interferon-α is effective for preventing recurrence of HCV-related HCC. Further studies are needed to clarify the efficacy of adjuvant immune checkpoint inhibitors. Adjuvant sorafenib appears to offer negligible clinical benefit and high risk of adverse effects.

Complete response by vitamin K2 analog monotherapy in sorafenib-failure advanced hepatocellular carcinoma: A case report

There have been reports that a vitamin K2 (VK2) analog is beneficial for the prevention of recurrence in hepatocellular carcinoma (HCC) patients after curative therapy. However, the VK2 analogs in current use do not appear to show dramatic antitumor effects when given alone. Here, we report the case of a 67-year-old male patient with sorafenib-failure advanced HCC who achieved complete response (CR) after VK2 analog monotherapy. At the time of sorafenib failure confirmation, the patient had multiple intrahepatic tumors, multiple lung metastases, and Vp3 portal vein tumor thrombosis. He had poor liver function (Child-Pugh score of 9, Child-Pugh class B) and poor performance status (Eastern Cooperative Oncology Group performance status 2). Both serum α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) levels were elevated (558 900 ng/mL and 917 300 mAU/mL, respectively). Treatment with VK2 analog was initiated at 45 mg/day. Five months later, both tumor markers had decreased to normal levels (AFP 8 ng/mL and DCP 10 mAU/mL). Contrast-enhanced computed tomography showed that all intrahepatic tumors had shrunk, there was no enhancement of tumor staining in the arterial phase, and all lung metastases and portal vein tumor thromboses had disappeared. We considered that CR was achieved according to the modified Response Evaluation Criteria in Solid Tumors. Eighteen months after the start of VK2 analog administration, the patient continues to receive treatment and has remained in CR without adverse events. Here, we report a rare case of sorafenib-failure advanced HCC in which sustained CR was achieved by VK2 analog monotherapy.

Mechanisms of PKC-Mediated Enhancement of HIF-1α Activity and its Inhibition by Vitamin K2 in Hepatocellular Carcinoma Cells

Hypoxia-inducible factor 1 (HIF-1) plays important roles in cancer cell biology. HIF-1α is reportedly activated by several factors, including protein kinase C (PKC), in addition to hypoxia. We investigated the role of PKC isoforms and the effects of vitamin K2 (VK2) in the activation process of HIF-1α. Human hepatocellular carcinoma (HCC)-derived Huh7 cells were cultured under normoxic and hypoxic (1% O₂) conditions with or without the PKC stimulator TPA. The expression, transcriptional activity and nuclear translocation of HIF-1α were examined under treatment with PKC inhibitors, siRNAs against each PKC isoform and VK2. Hypoxia increased the expression and activity of HIF-1α. TPA increased the HIF-1α activity several times under both normoxic and hypoxic conditions. PKC-δ siRNA-mediated knockdown, PKC-δ inhibitor (rottlerin) and pan-PKC inhibitor (Ro-31-8425) suppressed the expression and transcriptional activity of HIF-1α. VK2 significantly inhibited the TPA-induced HIF-1α transcriptional activity and suppressed the expression and nuclear translocation of HIF-1α induced by TPA without altering the HIF-1α mRNA levels. These data indicate that PKC-δ enhances the HIF-1α transcriptional activity by increasing the nuclear translocation, and that VK2 might suppress the HIF-1α activation through the inhibition of PKC in HCC cells.

Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease

Vitamin K is an essential bioactive compound required for optimal body function. Vitamin K can be present in various isoforms, distinguishable by two main structures, namely, phylloquinone (K1) and menaquinones (K2). The difference in structure between K1 and K2 is seen in different absorption rates, tissue distribution, and bioavailability. Although differing in structure, both act as cofactor for the enzyme gamma-glutamylcarboxylase, encompassing both hepatic and extrahepatic activity. Only carboxylated proteins are active and promote a health profile like hemostasis. Furthermore, vitamin K2 in the form of MK-7 has been shown to be a bioactive compound in regulating osteoporosis, atherosclerosis, cancer and inflammatory diseases without risk of negative side effects or overdosing. This review is the first to highlight differences between isoforms vitamin K1 and K2 by means of source, function, and extrahepatic activity.

Absence of antitumor effects of metformin in sorafenib-treated patients with hepatocellular carcinoma recurrence after hepatic resection and liver transplantation

Backgrounds/Aims

Hepatocellular carcinoma (HCC) recurrence following hepatic resection (HR) and liver transplantation (LT) remains a great concern. We assessed the antitumor effects of metformin in patients treated with sorafenib for HCC recurrence after HR or LT.

Methods

The two clinical retrospective studies involved metformin therapy of 304 HR patients and 74 LT recipients who were treated with sorafenib.

Results

In the study involving patients who had undergone HR, death occurred in 245 of the 304 patients (80.6%) during a median follow-up of 10.2 months after sorafenib administration. The metformin HR group (group 1; n=40) showed no prognostic difference in progression-free and overall survival rates compared with the all-HR control group (group 3; n=241) and propensity score-matched HR control group (group 4; n=80). In the clinical study of recipients exposed to LT, death occurred in 62 of the 74 patients (83.8%) during a median follow-up of 13.6 months (range: 3–76 months) after sorafenib administration. The metformin LT group (group 5; n=14) showed no prognostic difference in progression-free and overall survival rates compared with the all-LT control group (group 7; n=43) and propensity score-matched LT control group (group 8; n=28).

Conclusions

Our clinical studies demonstrated absence of synergistic antitumor effects of metformin. Further high-volume studies are necessary to assess the role of metformin in patients treated with sorafenib for advanced HCC.

Research progress on the anticancer effects of vitamin K2

Despite the availability of multiple therapeutic methods for patients with cancer, the long-term prognosis is not satisfactory in a number of different cancer types. Vitamin K2 (VK2), which exerts anticancer effects on a number of cancer cell lines, is considered to be a prospective novel agent for the treatment of cancer. The present review aims to summarize the results of studies in which VK2 was administered either to patients with cancer or animals inoculated with cancerous cells, particularly investigating the inhibitory effects of VK2 on cancerous cells, primarily involving cell-cycle arrest, cell differentiation, apoptosis, autophagy and invasion. The present review summarizes evidence stating that treatment with VK2 could positively inhibit the growth of cancer cells, making it a potentially useful approach for the prevention and clinical treatment of cancer. Additionally, the combination treatment of VK2 and established chemotherapeutics may achieve better results, with fewer side effects. Therefore, more attention should be paid to the effects of micronutrients on tumors.

Vitamin K and its analogs: Potential avenues for prostate cancer management

Epidemiological studies have demonstrated a relationship between cancer incidence and dietary habits. Especially intake of certain essential nutrients like vitamins has been shown to be beneficial in experimental studies and some clinical trials. Vitamin K (VK) is an essential nutrient involved in the blood clotting cascade, and there are considerable experimental data demonstrating its potential anticancer activity in several cancer types including prostate cancer. Previous in vitro and in vivo studies have focused mainly on anti-oxidative effects as the underlying anticancer mechanism of VK. However, recent studies reveal that VK inhibits the growth of cancer cells through other mechanisms, including apoptosis, cell cycle arrest, autophagy, and modulation of various transcription factors such as Myc and Fos. In the present review, we focus on the anticancer effect of dietary VK and its analogs on prostate cancer, with an emphasis on the signaling pathways that are activated following exposure to these compounds. This review also highlights the potential of VK and its derivatives as an adjuvant treatment in combination with other vitamins or with chemotherapeutic drugs. Based on our recent results and a review of the existing literature, we present evidence that VK and its derivatives can potentially be explored as cancer therapy, especially for prostate cancer.

Timely meta-analysis on the efficacy of adoptive immunotherapy for hepatocellular carcinoma patients after curative therapy

Aims

The role of adoptive immunotherapy (AIT) for patients with hepatocellular carcinoma (HCC) who have received curative therapy is still not well illustrated. This timely meta-analysis aims to update the current evidence on efficacy and safety of AIT for patients with HCC who have received curative therapy.

Methods

We searched PubMed, EMBASE, Scopus and the Cochrane Library Through January 2017 for relevant studies. Mortality and tumor recurrence were compared between patients with or without adjuvant AIT. The meta-analysis was performed using Review Manager 5.3.

Results

Eight studies involving 1861 patients met the eligibility criteria and were meta-analyzed. Adjuvant AIT was associated with significantly lower mortality at 1 year (RR 0.64, 95%CI 0.52–0.79), 3 years (RR 0.73, 95%CI 0.65–0.81) and 5 years (RR 0.86, 95%CI 0.79–0.94). Similarly, adjuvant AIT was associated with significantly lower recurrence rate than curative therapies alone at 1 year (RR 0.64, 95%CI 0.49–0.82), 3 years (RR 0.85, 95%CI 0.79–0.91) and 5 years (RR 0.90, 95%CI 0.85–0.95). Short-term outcomes were confirmed in sensitivity analyses based on randomized trials or choice of random- or fixed-effect meta-analysis model. None of the included patients experienced grade 4 adverse events.

Conclusions

This timely meta-analysis confirms the evidence that adjuvant AIT for patients with HCC after curative treatment lowers risk of mortality and tumor recurrence.

Vitamin K and hepatocellular carcinoma: The basic and clinic

Vitamin K (VK), which was originally identified as a cofactor involved in the production of functional coagulation factors in the liver, has been shown to be involved in various aspects of physiological and pathological events, including bone metabolism, cardiovascular diseases and tumor biology. The mechanisms and roles of VK are gradually becoming clear. Several novel enzymes involved in the VK cycle were identified and have been shown to be linked to tumorigenesis. The VKs have been shown to suppress liver cancer cell growth through multiple signaling pathways via the transcription factors and protein kinases. A VK2 analog was applied to the chemoprevention of hepatocellular carcinoma (HCC) recurrence after curative therapy and was shown to have beneficial effects, both in the suppression of HCC recurrence and in patient survival. Although a large scale randomized control study failed to demonstrate the suppression of HCC recurrence, a meta-analysis suggested a beneficial effect on the long-term survival of HCC patients. However, the beneficial effects of VK administration alone were not sufficient to prevent or treat HCC in clinical settings. Thus its combination with other anti-cancer reagents and the development of more potent novel VK derivatives are the focus of ongoing research which seeks to achieve satisfactory therapeutic effects against HCC.

An interim safety analysis of hepatocellular carcinoma patients administrating oral vitamin K with or without sorafenib

Backgrounds/Aims

Vitamin K may plays a role in controlling hepatocellular carcinoma (HCC) cell growth. In this study, we intended to present 5-year experience of 72 patients receiving oral vitamin K with or without sorafenib. Its end-point was to evaluate the safety of combination therapy using sorafenib and vitamin K.

Methods

An interim analysis was performed as a single-arm cross-sectional study, including 72 HCC patients who underwent liver resection or transplantation and administered oral vitamin K2 alone (n=47) or with sorafenib (n=25).

Results

In all patients, administration of vitamin K2 analog 45 mg/day did not show any noticeable adverse side-effect during vitamin K therapy of 23.3±10.6 months, except for one patient who experienced skin rash at the third day of vitamin K therapy. In 25 patients receiving sorafenib and vitamin K for 6 months or longer, any noticeable adverse side-effect suspected of vitamin K origin was not identified yet. A small proportion of patients showed unexpectedly favorable anti-tumor effects after use of vitamin K with or without sorafenib.

Conclusions

Because add-on of oral vitamin K did not increase the adverse side-effects of sorafenib, a combination therapy with these two agents appears to be worthy of further clinical trial with an expectation of synergistic therapeutic effects.

Adjuvant therapy for hepatocellular carcinoma after curative treatment

Hepatocellular carcinoma (HCC) is a common malignancy in the world. Although resection and various locoregional therapies can achieve eradication or complete ablation of small HCC, HCC recurrence after these therapies is still common. Although candidates for medical ablation usually exhibit compensated hepatic functional status, the frequent recurrence of HCC after successful ablation contributes to short survival. Therefore, attempts to prevent HCC recurrence are essential to prolong survival. Efforts in preventing HCC recurrence after curative therapies include prevention of early recurrence by improving liver immunity and eliminating microscopic tumor foci or micrometastases, and prevention of late recurrence by reducing the hepatitis activity and using antiviral therapies based on viral suppression/eradication. In HCC with vascular invasion, adjuvant transcatheter arterial chemoembolization should be considered to provide better control. Whether the adjuvant use of sorafenib may suppress microscopic tumor foci or micrometastases may be unveiled in the near future. This review article will update the algorithms, novel medication or study drugs in the prevention of HCC after curative therapies.

Adjuvant and chemopreventive therapies for resectable hepatocellular carcinoma: a literature review

The recurrence rate of hepatocellular carcinoma (HCC) after potentially curative hepatic resection (HR) is very high. Many clinical trials have explored the efficacy of several treatment modalities to prevent recurrence, including adjuvant and chemopreventive therapy, but they have often reported contradictory findings. As a result, most liver guidelines and liver seminars do not unequivocally endorse adjuvant or chemopreventive therapy for HCC patients after potentially curative HR. To examine the available evidence on this question, we comprehensively searched PubMed for controlled studies that included a supportive care or placebo control arm, and we used the GRADE system to classify and assess the results.

Transarterial embolization with or without chemotherapy for advanced hepatocellular carcinoma: a systematic review

Transarterial chemoembolization (TACE) and transarterial embolization (TAE) are commonly used as first-line treatment for patients with advanced hepatocellular carcinoma (HCC) and have been shown to improve overall survival (OS). However, there remain concerns regarding whether the benefit of the prolonged survival achieved with TACE is superior to the maximum cytotoxic effect of the associated chemotherapeutics. This systematic review aims to compare the efficiency of TACE and TAE based on randomized controlled trials (RCTs). MEDLINE, EMBASE, the Cochrane library, the Science Citation Index, and the Chinese National Knowledge Infrastructure databases were systematically searched through the end of April 2014. Risk ratios (RRs) and 95 % confidence intervals (CIs) were calculated. Meta-analysis of the RCTs was conducted to estimate the mortality and survival rate between the TACE and TAE groups. The analysis included five RCTs involving 582 patients. For all-cause mortality, TACE did not result in a statistically significant reduced incidence of adverse events than TAE with a pooled RR of 1.21 (95 % CI = 0.74-1.98, P = 0.16). In addition, 6-, 9-, 12-, 24-, and 36-month OS of the TACE group were not significantly higher than that of the TAE group (all P > 0.05). Interestingly, TACE resulted in a significantly higher rate of advanced events. The efficacy of TACE is not superior to TAE in advanced HCC patients. Moreover, TACE was associated with an increased rate of adverse events than TAE. Improved strategies are needed to reduce the risk of post-TACE complications.

Postoperative therapy options for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is associated with poor prognosis and often recurs even after curative hepatic resection (HR) or radiofrequency ablation (RFA). In fact, recurrence is the most frequent cause of postoperative death in patients with HCC; it can arise through intrahepatic metastasis by the primary tumor or through the emergence of de novo tumors. Even though studies have examined numerous adjuvant therapies and chemotherapies for their ability to prevent recurrence, no consensus recommendations exist about their clinical application. To gain a comprehensive picture of clinical options, we identified 39 randomized controlled trials, involving 4113 participants, which explore the efficacy of adjuvant or chemotherapies to prevent HCC recurrence after potentially curative HR or RFA. The available evidence suggests a significant improvement in recurrence-free survival and overall survival when transarterial chemoembolization is used for patients who are at high risk for recurrence, lamivudine for patients with hepatitis B virus (HBV)-related HCC (>500 copies of HBV DNA/ml), and interferon-α for patients with hepatitis C virus (HCV)-infected HCC. In contrast, available evidence does not definitively establish clinical benefits of interferon-β for patients with HCV-related HCC, interferon-α for patients with HBV-related HCC, or any of the following therapies for patients with HCC: iodine-125 brachytherapy, autologous tumor vaccination, adoptive immunotherapy, or therapy involving acyclic retinoid, vitamin K2 analog, iodine-131-labeled lipiodol, sorafenib, heparanase inhibitor PI-88, or capecitabine. Though the findings of our review should be interpreted with caution because of clinical heterogeneity and small sample size in the included trials, they highlight gaps in the evidence base, and therefore, may guide future research.

Chemopreventive strategies in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of death from cancer. The incidence and mortality of HCC are increasing in most Western countries as a result of an ageing cohort infected with chronic hepatitis C, and are expected to continue to rise as a consequence of the obesity epidemic. Chemopreventive strategies aimed at decreasing the risk or delaying the onset of HCC are needed. Universal immunization against HBV and antiviral therapy against HBV and HCV in patients with established disease has consistently been associated with reduced HCC risk, especially in patients who achieve sustained virologic response. However, the cost-effectiveness of antiviral therapy for primary HCC prevention is not known. Several commonly prescribed medications seem promising as chemopreventive agents against HCC, including statins, antidiabetic medications and aspirin. Dietary agents such as coffee, vitamin E and fish oil as well as phytochemicals might also be associated with reduced risk of HCC. Though randomized controlled trials are ideally needed to firmly establish efficacy, such chemoprevention trials are logistically and ethically challenging. Well-designed, prospective, population-based cohort studies might provide the best evidence for chemopreventive efficacy of these agents.

Antiviral therapy for hepatitis B virus-related hepatocellular carcinoma after radical hepatectomy

Objective

To assess the effect of antiviral therapy for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after radical hepatectomy.

Methods

A total of 478 HBV-related HCC patients treated by radical hepatectomy were retrospectively collected. Patients in the treatment group (n=141) received postoperative lamivudine treatment (100 mg/d), whereas patients in the control group (n=337) did not. Recurrence-free survival (RFS) rates, overall survival (OS) rates, treatments for recurrent HCC and cause of death were compared between the two groups. Propensity score matching (PSM) analysis was also conducted to reduce confounding bias between the two groups.

Results

The 1-, 3-, and 5-year RFS rates didn't significantly differ between the two groups (P=0.778); however, the 1-, 3-, and 5-year OS rates in the treatment group were significantly higher than those in the control group (P=0.002). Similar results were observed in the matched data. Subgroup analysis showed that antiviral treatment conferred a significant survival benefit for Barcelona Clinical Liver Cancer stage A/B patients. Following HCC recurrence, more people in the treatment group were able to choose curative treatments than those in the control group (P=0.031). For cause of death, fewer people in the treatment group died of liver failure than those in the control group (P=0.041).

Conclusion

Postoperative antiviral therapy increases chances of receiving curative treatments for recurrent HCC and prevents death because of liver failure, thereby significantly prolonging OS, especially in early- or intermedian-stage tumors.

Dynamical observation on biological progression of VX2 liver tumors to identify the optimal time for intervention in animal models

Purpose

Based on practice guideline of “management of hepatocellular carcinoma (HCC): update” published by American Association for the Study of Liver Diseases (AASLD) and “Barcelona Clinic Liver Cancer staging system (BCLC),” this study investigated how to enroll the optimal VX2 liver tumor model for HCC researches by dynamically observing the biological progression of the tumor.

Materials

Thirty-two healthy New Zealand white rabbits were implanted VX2 liver tumor by cell suspension method (n=24) and tissue fragment method (n=8). All the rabbits underwent CT scans on day 7, 14, 21 and 28 after implantation to observe the size of the tumors, the time when metastases and ascites occurred and the survival time. Appropriate intervention times were estimated corresponding to different clinical HCC stages by using tumor diameter-time curve.

Results

The VX2 liver tumors grew rapidly within 28 days after implantation. And the tumors in the cell suspension group grew faster than those of the tissue fragment group. The appropriate intervention time corresponding to very early stage, early stage and intermediate stage were <11 days, 11–16.9 days and >16.9 days, respectively in the cell suspension group, and <19.9 days, 19.9–25.5 days and >25.5 days, respectively in the tissue fragment group.

Conclusion

Preclinical animal research needs to improve on different levels to yield best predictions for human patients. Researchers should seek for an individualized proposal to select optimal VX2 liver tumor models for their experiments. This approach may lead to a more accurate determination of therapeutic outcomes.