High serum vascular endothelial growth factor levels predict poor prognosis after radiofrequency ablation of hepatocellular carcinoma: importance of tumor biomarker in ablative therapies

Neoadjuvant therapies in resectable hepatocellular carcinoma: Exploring strategies to improve prognosis

Hepatocellular carcinoma (HCC), a challenging malignancy, often necessitates surgical intervention, notably liver resection. However, the high recurrence rate, reaching 70% within 5 years post-resection, significantly impacts patient outcomes. Neoadjuvant therapies aim to preoperatively address this challenge, reducing lesion size, improving surgical resection rates, deactivating potential micro-metastases, and ultimately lowering postoperative recurrence rates. This review concentrates on advances in research on and clinical use of neoadjuvant therapies for HCC, with particular attention to the use of immune checkpoint inhibitors (ICIs) targeting programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4). Ongoing clinical studies exploring immunotherapy combined with a tyrosine kinase inhibitor (TKI), interventional therapy, radiotherapy, and other modalities offer promising insights into overcoming resistance to monotherapies. In summary, neoadjuvant therapies hold significant promise in terms of improving the prognosis for patients with HCC and enhancing long-term survival, particularly through innovative combination strategies.

Unraveling the hypoxia modulating potential of VEGF family genes in pan-cancer

Tumor hypoxia, oxygen deprivation state, occurs in most cancers and promotes angiogenesis, enhancing the potential for metastasis. The vascular endothelial growth factor (VEGF) family genes play crucial roles in tumorigenesis by promoting angiogenesis. To investigate the malignant processes triggered by hypoxia-induced angiogenesis across pan-cancers, we comprehensively analyzed the relationships between the expression of VEGF family genes and hypoxic microenvironment based on integrated bioinformatics methods. Our results suggest that the expression of VEGF family genes differs significantly among various cancers, highlighting their heterogeneity effect on human cancers. Across the 33 cancers, VEGFB and VEGFD showed the highest and lowest expression levels, respectively. The survival analysis showed that VEGFA and placental growth factor (PGF) were correlated with poor prognosis in many cancers, including kidney renal cell and liver hepatocellular carcinoma. VEGFC expression was positively correlated with glioma and stomach cancer. VEGFA and PGF showed distinct positive correlations with hypoxia scores in most cancers, indicating a potential correlation with tumor aggressiveness. The expression of miRNAs targeting VEGF family genes, including hsa-miR-130b-5p and hsa-miR-940, was positively correlated with hypoxia. In immune subtypes analysis, VEGFC was highly expressed in C3 (inflammatory) and C6 (transforming growth factor β dominant) across various cancers, indicating its potential role as a tumor promotor. VEGFC expression exhibited positive correlations with immune infiltration scores, suggesting low tumor purity. High expression of VEGFA and VEGFC showed favorable responses to various drugs, including BLU-667, which abrogates RET signaling, an oncogenic driver in liver and thyroid cancers. Our findings suggest potential roles of VEGF family genes in malignant processes related with hypoxia-induced angiogenesis.

Mechanisms and therapeutic strategies to combat the recurrence and progression of hepatocellular carcinoma after thermal ablation

Thermal ablation (TA), including radiofrequency ablation (RFA) and microwave ablation (MWA), has become the main treatment for early-stage hepatocellular carcinoma (HCC) due to advantages such as safety and minimal invasiveness. However, HCC is prone to local recurrence, with more aggressive malignancies after TA closely related to TA-induced changes in epithelial-mesenchymal transition (EMT) and remodeling of the tumor microenvironment (TME). According to many studies, various components of the TME undergo complex changes after TA, such as the recruitment of innate and adaptive immune cells, the release of tumor-associated antigens (TAAs) and various cytokines, the formation of a hypoxic microenvironment, and tumor angiogenesis. Changes in the TME after TA can partly enhance the anti-tumor immune response; however, this response is weak to kill the tumor completely. Certain components of the TME can induce an immunosuppressive microenvironment through complex interactions, leading to tumor recurrence and progression. How the TME is remodeled after TA and the mechanism by which the TME promotes HCC recurrence and progression are unclear. Thus, in this review, we focused on these issues to highlight potentially effective strategies for reducing and preventing the recurrence and progression of HCC after TA.

Integrated manganese (III)-doped nanosystem for optimizing photothermal ablation: Amplifying hyperthermia-induced STING pathway and enhancing antitumor immunity

Despite the great promise initially demonstrated by photothermal ablation (PTA) therapy, its inability to completely ablate large tumors is problematic, because this has been found to result in residual tumors at ablation margins and bring a relative high rate of subsequent recurrences and metastases. To address this issue, we herein report a smart photothermal nanosystem (PBM) based on FDA-approved Prussian blue (PB) nanoparticles, doped with Mn (III) to suppress the tumor debris left by incomplete ablation. Notably, our study demonstrated that PTA-induced hyperthermia plays a crucial role in initiating the cGAS-STING pathway by generating damaged cytosolic DNA. This PBM nanosystem, which consumes glutathione and continuously releases Mn(II), further amplifies the PTA-induced cGAS-STING pathway in CT26 colon and 4T1 breast tumor models. Moreover, treatment with PBM following PTA boosted the robust immune response in situ and extended to the whole body with a remarkable suppression effect on both local residual and distant tumors. This work, which improves the antitumor efficacy of nonablated areas utilizing hyperthermia-enhanced immune therapy, may therefore provide a promising adjuvant antitumor strategy for the issue of incomplete ablation. STATEMENT OF SIGNIFICANCE: This work discovered, for the first time, that photothermal ablation-induced hyperthermia plays a crucial role in initiating the cGAS-STING pathway. Taking advantage of this finding, we developed a smart photothermal material (PBM) tailored for incomplete tumor ablation. This integrated Mn(III)-doped nanosystem (PBM) demonstrated superior therapeutic benefits due to the thermal ablation process and immune enhancement. As the photothermal ablation-induced cGAS-STING pathway was triggered, the released Mn(III) consumes GSH while continuously transferred to Mn(II), which further amplified STING activation and facilitated a more robust antitumor immunity, thereby remarkably inhibiting both local residual and distant tumors in virtue of the biological changes under thermal ablation.

Effect of Transcatheter Arterial Chemoembolization Combined with Radiofrequency Ablation on Liver Function and Immune Function in Patients with Hepatocellular Carcinoma

Objectives

To investigate the effects of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) on liver function and immune function in patients with hepatocellular carcinoma (HCC).

Methods

From December 2016 to January 2019, patients with primary liver cancer who could not be operated on were selected as the study subjects. 170 patients were randomly divided into two groups. The control group was treated with transcatheter arterial chemoembolization (n = 85). The patients in the observation group were treated with transcatheter arterial chemoembolization combined with radiofrequency ablation (n = 85). The clinical effects of the two groups were analyzed. The changes of liver function and immune function were detected by automatic biochemical analyzer before and after treatment. The changes of hypoxia inducible factor-1 (HIF1) alpha and vascular endothelial growth factor (VEGF) levels before and after treatment were analyzed by enzyme-linked immunosorbent assay (ELISA).

Results

The total effective rate in the observation group was significantly higher than that in the control group (P < 0.05). After treatment, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), CD8+, HIF1 alpha, and VEGF decreased significantly (P < 0.05), while levels of total bilirubin, direct bilirubin, indirect bilirubin, CD3+, CD4+, and CD4+/CD8+ increased significantly (P < 0.05). The changes of the above indexes in the observation group were more significant than those in the control group (P < 0.05).

Conclusion

Hepatic arterial chemoembolization combined with radiofrequency ablation has a significant effect on liver function and immune function in patients with liver cancer, which may be related to the abnormal levels of HIF1α and vascular endothelial growth factor.

Hepatitis B virus small envelope protein promotes HCC angiogenesis via ER stress signaling to upregulate VEGFA expression

Hepatocellular carcinoma (HCC) is a hypervascular tumor and accumulating evidence has indicated that stimulation of angiogenesis by HBV may contribute to HCC malignancy. The small protein of hepatitis B virus surface antigen (HBsAg), SHBs, is the most abundant HBV viral protein and has a close clinical association with HCC, however, whether SHBs contributes to HCC angiogenesis remains unknown. This study reports that forced expression of SHBs in HCC cells promoted xenograft tumor growth and increased the microvessel density (MVD) within the tumors. Consistently, HBsAg was also positively correlated with MVD count in HCC patients' specimens. The conditioned media from the SHBs-transfected HCC cells increased the capillary tube formation and migration of human umbilical vein endothelial cells (HUVECs). Intriguingly, overexpression of SHBs increased VEGFA expression at both mRNA and protein levels. A higher VEGFA expression level was also observed in the xenograft tumors transplanted with SHBs-expressing HCC cells and in HBsAg-positive HCC tumor tissues as compared to their negative controls. As expected, in the culture supernatants, the secretion of VEGFA was also significantly enhanced from HCC cells expressing SHBs, which promoted HUVECs migration and vessel formation. Furthermore, all the three unfolded protein response (UPR) sensors IRE1α, PERK and ATF6 associated with endoplasmic reticulum (ER) stress were found activated in the SHBs-expressing cells and correlated with VEGFA protein expression and secretion. Taken together, these results suggest an important role of SHBs in HCC angiogenesis and may highlight a potential target for preventive and therapeutic intervention of HBV-related HCC and its malignant progression. IMPORTANCE Chronic hepatitis B virus infection is one of the important risk factors for the development and progression of hepatocellular carcinoma (HCC). HCC is characteristic of hypervascularization even at early phases of the disease due to overexpression of angiogenic factors like vascular endothelial growth factor-A (VEGFA). However, a detailed mechanism in the HBV-induced angiogenesis remains to be established. In this study, we demonstrate for the first time that the most abundant HBV viral protein, i.e. small surface antigens (SHBs) can enhance the angiogenic capacity of HCC cells by upregulation of VEGFA expression both in vitro and in vivo. Mechanistically, SHBs induced endoplasmic reticulum (ER) stress which consequently activated unfolded protein response (UPR) signaling to increase VEGFA expression and secretion. This study suggests that SHBs plays an important pro-angiogenic role in HBV-associated HCC and may represent a potential target for anti-angiogenic therapy in the HCC.

Immunological Markers, Prognostic Factors and Challenges Following Curative Treatments for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortalities worldwide. Patients with early-stage HCC are eligible for curative treatments, such as surgical resection, liver transplantation (LT) and percutaneous ablation. Although curative treatments provide excellent long-term survival, almost 70–80% of patients experience HCC recurrence after curative treatments. Tumor-related factors, including tumor size, number and differentiation, and underlying liver disease, are well-known risk factors for recurrence following curative therapies. Moreover, the tumor microenvironment (TME) also plays a key role in the recurrence of HCC. Many immunosuppressive mechanisms, such as an increase in regulatory T cells and myeloid-derived suppressor cells with a decrease in cytotoxic T cells, are implicated in HCC recurrence. These suppressive TMEs are also modulated by several factors and pathways, including mammalian target of rapamycin signaling, vascular endothelial growth factor, programmed cell death protein 1 and its ligand 1. Based on these mechanisms and the promising results of immune checkpoint blockers (ICBs) in advanced HCC, there have been several ongoing adjuvant studies using a single or combination of ICB following curative treatments in HCC. In this review, we strive to provide biologic and immunological markers, prognostic factors, and challenges associated with clinical outcomes after curative treatments, including resection, LT and ablation.

Genetic Heterogeneity, Therapeutic Hurdle Confronting Sorafenib and Immune Checkpoint Inhibitors in Hepatocellular Carcinoma

Despite the latest advances in hepatocellular carcinoma (HCC) screening and treatment modalities, HCC is still representing a global burden. Most HCC patients present at later stages to an extent that conventional curative options are ineffective. Hence, systemic therapy represented by the tyrosine kinase inhibitor, sorafenib, in the first-line setting is the main treatment modality for advanced-stage HCC. However, in the two groundbreaking phase III clinical trials, the SHARP and Asia-Pacific trials, sorafenib has demonstrated a modest prolongation of overall survival in almost 30% of HCC patients. As HCC develops in an immune-rich milieu, particular attention has been placed on immune checkpoint inhibitors (ICIs) as a novel therapeutic modality for HCC. Yet, HCC therapy is hampered by the resistance to chemotherapeutic drugs and the subsequent tumor recurrence. HCC is characterized by substantial genomic heterogeneity that has an impact on cellular response to the applied therapy. And hence, this review aims at giving an insight into the therapeutic impact and the different mechanisms of resistance to sorafenib and ICIs as well as, discussing the genomic heterogeneity associated with such mechanisms.

Is serum endocan a sensitive biomarker for early recurrence of hepatocellular carcinoma after radiofrequency ablation?

BACKGROUND AND AIM OF THE WORK

Hepatocellular cancer (HCC) is one of the common liver cancers and considered to be the sixth most commonly occurring cancer in the world and the second leading cause of death among cancer patients. More recent studies on HCC showed that the elevated serum endocan level was a predictive factor of recurrence after radiofrequency ablation. The aim of this study is to evaluate the serum endocan level as a prognostic biomarker for recurrence of HCC after percutaneous radiofrequency ablation.

PATIENTS AND METHODS

Analytic-prospective study was carried out in Suez Canal University Hospitals. The study was carried out on 80 patients classified into three groups: group 1 (control group) consisted of 20 apparently healthy persons; group 2 consisted of 20 patients with liver cirrhosis; and group 3 consisted of 40 treatment-naive HCC patients who were prepared for radiofrequency ablation. All HCC patients (who were confirmed to have complete ablation after RF) were followed up by using triphasic abdominal CT, serum AFP and serum endocan assessment at 3 and 6 months after radiofrequency ablation.

RESULTS

Our study revealed a high level of serum endocan in the HCC group with a statistically significant difference (<0.001) between the three groups. HCC patients had a higher level of serum endocan (6.2 ± 2.25) followed by an liver cirrhosis group (2.0 ± 1.29) and then the control group (1.0 ± 0.3). The serum endocan level had a positive correlation with recurrence of HCC (P < 0.0001). There was a positive correlation between serum endocan and serum alanine transferase (P = 0.02), and a positive correlation between serum endocan and the number of tumors (P = 0.01).

CONCLUSION

Serum endocan is considered as a prognostic biomarker for tumor recurrence in HCC patients after radiofrequency ablation.

Determination of VEGF165 using impedimetric aptasensor based on cyclohexanehexone-melem covalent-organic framework

A porous nanostructured covalent-organic framework (COF) has been prepared via condensation polymerization between the two building blocks of melem and hexaketocyclohexane octahydrate (represented as M-HO-COF). Basic characterizations revealed that the M-HO-COF network was composed of C=N and highly conjugated aromatic moieties, along with a high surface area, large pore size, remarkable electrochemical activity, and strong bioaffinity toward aptamer strands. Given that the vascular endothelial growth factor 165 (VEGF₁₆₅)-targeted aptamer was stably anchored over M-HO-COF via weak intermolecular forces, the prepared M-HO-COF network exhibited great potential as a sensitive and selective platform for the impedimetric VEGF₁₆₅ aptasensor. Consequently, the M-HO-COF-based aptasensor displayed an ultralow limit of detection of 0.18 fg mL^-1 within a wide range of VEGF₁₆₅ concentrations from 1 fg mL^-1 to 10 ng mL^-1. Considering its strong fluorescence performance, excellent biocompatibility, and small nanosheet-like structure, the obtained COF-based aptasensor showed a superior sensing performance and regeneration capability after 7 regeneration cycles for the detection of osteosarcoma cells (K7M2 cells), which overexpressed with VEGF₁₆₅, with a low limit of detection of 49 cells mL^-1. For real f human serum samples, the obtained COF-based aptasensor exhibits acceptable mean apparent recoveries of 97.41% with a relative standard deviation of 4.60%. Furthermore, the proposed bifunctional aptasensor for the detection VEGF₁₆₅ and K7M2 cells exhibited good stability, appropriate selectivity toward other biomarkers or normal cells, acceptable reproducibility, and applicability. A bifunctional sensing system was constructed for detecting osteosarcoma cells (K7M2 cells) and VEGF₁₆₅ based on the a porous nanostructured covalent-organic framework (M-HO-COF) via condensation polymerization between melem and hexaketocyclohexane octahydrate. The M-HO-COF-based aptasensor displayed ultralow detection limit of 0.18 fg mL^-1 toward VEGF₁₆₅ and 49 cell mL^-1 for K7M2 cells with high selectivity, acceptable reproducibility, and good stability.

Locoregional therapies in the era of molecular and immune treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality and has an increasing incidence worldwide. Locoregional therapies, defined as imaging-guided liver tumour-directed procedures, play a leading part in the management of 50-60% of HCCs. Radiofrequency is the mainstay for local ablation at early stages and transarterial chemoembolization (TACE) remains the standard treatment for intermediate-stage HCC. Other local ablative techniques (microwave ablation, cryoablation and irreversible electroporation) or locoregional therapies (for example, radioembolization and sterotactic body radiation therapy) have been explored, but have not yet modified the standard therapies established decades ago. This understanding is currently changing, and several drugs have been approved for the management of advanced HCC. Molecular therapies dominate the adjuvant trials after curative therapies and combination strategies with TACE for intermediate stages. The rationale for these combinations is sound. Local therapies induce antigen and proinflammatory cytokine release, whereas VEGF inhibitors and tyrosine kinase inhibitors boost immunity and prime tumours for checkpoint inhibition. In this Review, we analyse data from randomized and uncontrolled studies reported with ablative and locoregional techniques and examine the expected effects of combinations with systemic treatments. We also discuss trial design and benchmarks to be used as a reference for future investigations in the dawn of a promising new era for HCC treatment.

Tumor Biomarkers and Interventional Oncology: Impact on Local Outcomes for Liver and Lung Malignancy

PURPOSE OF REVIEW

Interventional oncology (IO) loco-regional treatments are widely utilized in clinical practice. However, local tumor control rates are still widely variable. There is a need to identify and develop novel biomarkers prognosticators following IO therapies. Here, we review the current literature on molecular tumor biomarkers in IO, mainly focusing on patients with liver and lung cancers.

RECENT FINDINGS

RAS mutation is a prognosticator for patients with colorectal liver metastases. Several promising serum metabolites, gene signatures, circulating tumor nucleotides, and peptides are being evaluated for patients with hepatocellular carcinoma. Ki-67 and RAS mutation are independent risk factors for local tumor progression in the ablation of lung cancer. The relevant interplay between specific tumor biomarkers and IO loco-regional therapies outcomes has brought a new vision in the management of cancer. Further evolution of personalized interventional oncology accordingly to tumor biomarkers should improve oncologic outcomes for patients receiving IO therapies.

The Prognostic Value of Circulating VEGF-A Level in Patients With Hepatocellular Cancer

Background:

Neovascularization plays a crucial pathogenic role in tumor development and vascular endothelial growth factor (VEGF-A) is a key signaling element that drives angiogenesis, thereby facilitating hepatocellular cancer (HCC) growth and metastasis. We aimed to define the relationship between serum VEGF-A levels and clinical outcomes in a cohort of Turkish patients with HCC.

Methods:

We enrolled and prospectively followed 84 patients with HCC in our study. Serum VEGF-A levels were measured and we assessed the association between VEGF-A levels and clinical features.

Results:

Forty-eight patients had cirrhosis while 35 patients were noncirrhotic. Serum VEGF-A levels were significantly lower in HCC patients with cirrhosis compared to non-cirrhotic HCC patients (p = 0.03).In terms of viral hepatitis subtype, 36 (%42.8) of patients were hepatitis B virus (HBV) positive and 8 (%9.5) of patients were hepatitis C virus (HCV) positive. Patients with serum VEGF-A levels ≥100 pg/mL had significantly lower OS rates than patients with serum VEGF-A level <100 pg/mL (p = 0.01). The OS rates were 5.8 and 14.2 months, respectively (p = 0.02). The median OS was 7.38 months (95% CI: 5.89-13.79 months). We observed a significant relationship between serum VEGF-A level and tumor size. Patients with tumor size ≤ 5cm had lower VEGF-A levels than patients with VEGF-A levels <5 cm. The VEGF-A levels were 132.7 and 342.1 pg/mL, respectively (p < 0.001). The median follow-up was 32 months.

Conclusions:

Serum VEGF-A level, a biological marker of angiogenesis, is an independent predictor of survival in patients with HCC. Serum VEGF-A levels may be utilized to predict response to treatment targeting serum VEGF-A in patients with HCC.

Serum Vascular Endothelial Growth Factor in Patients with Hepatocellular Carcinoma and its Validity as a Tumor Biomarker

Background:

Hepatocellular Carcinoma (HCC) is one of the most common cancers associated with deaths worldwide and the presence of valid biomarkers for early diagnosis in high-risk patients can ameliorate the outcome of HCC. Vascular Endothelial Growth Factor (VEGF) has been found to play an essential role in the process of HCC growth and progression.

Objectives:

Therefore, we evaluated the serum VEGF levels in patients with HCC and liver cirrhosis and estimated its significant value for differentiating HCC patients from liver cirrhosis patients.

Material and methods:

Eighty-one subjects were enrolled in the study, 30 patients had HCC, 31 patients had liver cirrhosis and 20 were healthy control subjects. VEGF and AFP were measured using ELIZA. Abdominal ultrasound and triphasic abdominal computed tomography were performed in all subjects. Receiver Operating Characteristics curve analysis was performed for serum VEGF to determine its validity as a tumor biomarker.

Results:

The median levels of the serum VEGF were highly expressed in the HCC group (418 pg/ml) and the liver cirrhosis group (308 pg/ml) with no significant difference (P = 0.767); however both groups showed a significant increase compared to the control group (0.8 pg/ml, P <0.000). Serum VEGF showed high sensitivity (100%) and high specificity (100%) in differentiating HCC patients from controls with a cut-off value of ≥ 64.2 pg/ml, although it showed low sensitivity (29.2%) and specificity (85.7%) for differentiating HCC patients from liver cirrhosis patients.

Conclusion:

VEGF can be used as a reliable biomarker for differentiating HCC patients from healthy subjects but it can't be used as a reliable biomarker for differentiating HCC patients from high-risk patients as liver cirrhosis. The elevated serum VEGF levels in HCC and liver cirrhosis patients can elucidate the crucial role of angiogenesis in HCC and liver cirrhosis.

Repeated Transarterial Chemoembolization with Degradable Starch Microspheres (DSMs-TACE) of Unresectable Hepatocellular Carcinoma: A Prospective Pilot Study

OBJECTIVE

The aims of this study were to: a) evaluate tumor response rates using modified-Response-evaluation-criteria-in-solid-tumors (mRecist) criteria, b) evaluate safety of Degradable Starch Microspheres Trans-arterial-chemo-embolization (DSMs-TACE) for unresectable hepatocellular-carcinoma (HCC) treatment.

MATERIALS AND METHODS

We prospectively enrolled 24 HCC cirrhotic patients (21/3 M/F, mean age 66.3 years) to be treated with repeated DSMs-TACE procedures, performed at 4-6 week intervals on the basis of tumor response and patients tolerance. Clinical and biochemical evaluations were performed before and after each procedure. Treatment response was also assessed by Computed-tomography (CT) or Magnetic-resonance-imaging (MRI)-scan 4-6 weeks following each procedure.

RESULTS

In our experience, DSMs-TACE was both safe and effective. A total of 53 DSMs-TACE procedures were performed (2.2 per patient). No procedure-related death was observed. Complete Response (CR) was observed in 5/24 (20.8%), 4/17 (23.5%) and 5/12 (41.6%) patients after the first, second and third procedure, respectively. At the end of each treatment, all patients experienced at least a partial response. At the end of the repeated procedures, no differences between mono- or bi-lobar disease were observed in patients with CR (64.2% vs 50%; p=ns). In most cases, treatment discontinuation was due to worsening liver function.

CONCLUSION

DSMs-TACE is a valid, well-tolerated alternative treatment to Lipiodol-TACE or DEB-TACE, as it has demonstrated to achieve a relatively high percentage of complete tumor necrosis. CR rates were similar between patients with mono- or bi-lobar disease indicating the possibility of carrying-out repeated procedure in a safe and effective way in both types of patients.

Integrating interventional oncology in the treatment of liver tumors

Background

Percutaneous ablation techniques offer a vast armamentarium for local, minimally invasive treatment of liver tumors, nowadays representing an established therapeutic option, which is integrated in treatment algorithms, especially for non-resectable liver tumors. The results of ablative treatment compare very well to surgical treatment in liver lesions, and confirm that these techniques are a valuable option for bridging for transplantation. Different techniques have been established to perform tumor ablation, and the feasibility varies according to the procedure and technical skills of the operator, depending on the size and location of the liver lesion. In recent years, stereotactic multi-needle techniques using 3D trajectory planning, general anesthesia, and tube disconnection during needle placement have had a strong impact on the application range of ablation for liver tumors.

Conclusion

It is well known that creating a sufficient ablation margin and overlapping ablation zones is one key issue to enable ablation of large liver lesions with tumor-free margins (A0 ablation in analogy to R0 resection). Image fusion during treatment and follow-up assure highly accurate staging procedures and interventional planning.

Novel aspects

Review on the standards in ablation techniques for the treatment of liver tumors. Update on different ablation techniques, indications, and contraindications for percutaneous liver tumor treatment. Summary of recently published reports on liver tumor ablation.

Percutaneous treatment of hepatocellular carcinoma: State of the art and innovations

Percutaneous treatment of hepatocellular carcinoma (HCC) encompasses a vast range of techniques, including monopolar radiofrequency ablation (RFA), multibipolar RFA, microwave ablation, cryoablation and irreversible electroporation. RFA is considered one of the main curative treatments for HCC of less than 5 cm developing on cirrhotic liver, together with surgical resection and liver transplantation. However, controversies exist concerning the respective roles of ablation and liver resection for HCC of less than 3 to 5 cm on cirrhotic liver. In line with the therapeutic algorithm of early HCC, percutaneous ablation could also be used as a bridge to liver transplantation or in a sequence of upfront percutaneous treatment, followed by transplantation if the patient relapses. Moreover, several innovations in ablation methods may help to efficiently treat early HCC, initially considered as "non-ablatable", and might, in some cases, extend ablation criteria beyond early HCC, enabling treatment of more patients with a curative approach.

Early sorafenib induction after transarterial chemoembolization for unresectable hepatocellular carcinoma: Can sorafenib after TACE improve loco-regional control?

This prospective study aimed to estimate the efficacy of sorafenib therapy after transarterial chemoembolization (TACE) for unresectable hepatocellular carcinoma (HCC). Between July 2011 and March 2013, 17 patients were enrolled, 11 of whom received sorafenib therapy. Patients who previously received TACE for HCC and whose disease progressed within a six-month period were given 400-800 mg sorafenib orally, once or twice daily, within the 3 weeks after a second TACE (sorafenib after TACE group). The response to treatment, time to progression (TTP), overall survival (OS), and adverse events (AEs) were recorded. Of the 113 patients who underwent initial TACE for unresectable HCC between January 1995 and January 2013, 23 patients were selected who were treated with TACE alone, and for whom the interval between the second and third TACE treatments was <6 months (TACE alone group). The interval (TTP) was calculated between the third and fourth TACE treatments, then TTP was compared among the three groups: Sorafenib after TACE for > or <4 months; and TACE alone. During a median follow-up period of 34.4 months (range, 5.9-51.7 months) in both groups receiving sorafenib after TACE, sorafenib prolonged TTP (3.9 months) and OS (34.4 months). It was demonstrated that sorafenib use for >4 months prolonged TTP (5.7 months) significantly compared with use for <4 months (3.0 months) (P=0.002). The OS of patients given sorafenib for >4 months (35.9 months) was longer than that of patients who received the drug for <4 months (17.2 months), but this difference was not significant. In the TACE alone group, the median TTP between the third and fourth TACE treatments was 4.3 months. TTP decreased among the groups in the following order: Sorafenib for >4 months, TACE alone, and sorafenib for <4 months. There were three AEs of grade 3 in the present study. Two patients demonstrated a decrease in liver reserve function following sorafenib treatment, but improved immediately after sorafenib administration was stopped. Sorafenib induction early after TACE for unresectable HCC was generally well tolerated and significantly improved TTP. Further studies are required to confirm the safety and efficacy of this combination therapy.

Chemotherapy for Hepatocellular Carcinoma: Current Evidence and Future Perspectives

Hepatocarcinogenesis is a multistep process, heralded by abnormalities in cell differentiation and proliferation and sustained by an aberrant neoangiogenesis. Understanding the underlying molecular pathogenesis leading to hepatocellular carcinoma is a prerequisite to develop new drugs that will hamper or block the steps of these pathways. As hepatocellular carcinoma has higher arterial vascularization than normal liver, this could be a good target for novel molecular therapies. Introduction of the antiangiogenic drug sorafenib into clinical practice since 2008 has led to new perspectives in the management of this tumor. The importance of this drug lies not only in the modest gain of patients' survival, but in having opened a roadmap towards the development of new molecules and targets. Unfortunately, after the introduction of sorafenib, during the last years, a wide number of clinical trials on antiangiogenic therapies failed in achieving significant results. However, many of these trials are still ongoing and promise to improve overall survival and progression-free survival. A recent clinical trial has proven regorafenib effective in patients showing tumor progression under sorafenib, thus opening new interesting therapeutic perspectives. Many other expectations have been borne from the discovery of the immune checkpoint blockade, already known in other solid malignancies. Furthermore, a potential role in hepatocellular carcinoma therapy may derive from the use of branched-chain amino acids and of nutritional support. This review analyses the biomolecular pathways of hepatocellular carcinoma and the ongoing studies, the actual evidence and the future perspectives concerning drug therapy in this open field.

Interventional Oncology in Hepatocellular Carcinoma: Progress Through Innovation

The clinical management of hepatocellular carcinoma has evolved greatly in the last decade mostly through recent technical innovations. In particular, the application of cutting-edge image guidance has led to minimally invasive solutions for complex clinical problems and rapid advances in the field of interventional oncology. Many image-guided therapies, such as transarterial chemoembolization and radiofrequency ablation, have meanwhile been fully integrated into interdisciplinary clinical practice, whereas others are currently being investigated. This review summarizes and evaluates the most relevant completed and ongoing clinical trials, provides a synopsis of recent innovations in the field of intraprocedural imaging and tumor response assessment, and offers an outlook on new technologies, such as radiopaque embolic materials. In addition, combination therapies consisting of locoregional therapies and systemic molecular targeted agents (e.g., sorafenib) remain of major interest to the field and are also discussed. Finally, we address the many substantial advances in immune response pathways that have been related to the systemic effects of locoregional therapies. Knowledge of these new developments is crucial as they continue to shape the future of cancer treatment, further establishing interventional oncology along with surgical, medical, and radiation oncology as the fourth pillar of cancer care.

Oxidative stress mediates an increased formation of vascular endothelial growth factor in human hepatocarcinoma cells exposed to erlotinib

The tyrosine kinase inhibitor erlotinib targets the receptor of epidermal growth factor (EGFR) involved in development of hepatocellular carcinoma (HCC).

Although inefficient in established HCC, erlotinib has been recently proposed for HCC chemoprevention. Since Cyp3A4 and Cyp1A2 enzymes metabolize erlotinib in the liver, the insights into the mechanisms of erlotinib effects on liver cells with maintained drug metabolizing activity are needed.

We applied erlotinib to both commercially available (SNU398, Huh7) and established in Austria HCC cell lines (HCC-1.2, HCC-3). Cyp3A4 and Cyp1A2, microarray gene expression, cell viability, LDH release, DHFC fluorescence were assessed. VEGF expression was analysed by real-time RT-PCR and ELISA.

Higher cumulative expression of erlotinib metabolizing enzymes was observed in HCC-1.2 and HCC-3 cells. Gene expression microarray analysis showed upregulation of VEGF signalling by erlotinib. VEGF was increased up to 134 ± 14% (n = 5, p = 0.002) in HCC-1.2, HCC-3 and Huh7 cells. Interventions by Cyp1A2 and Mek2siRNA, MEK inhibitor UO126, diphenylene iodonium, as well as a combination of N-acetylcysteine with selenium all inhibited VEGF upregulation caused by erlotinib.

Thus, erlotinib increases VEGF production by mechanisms involving Cyp1A2, oxidative stress and MEK1/2. VEGF may favour angiogenesis and growth of early HCC tumours limiting the therapeutic and chemopreventive effects of erlotinib.

Science to Practice: Systemic Implications of Ablative Tumor Therapies-Reality Uncovered and Myths Exposed?

In their effort to characterize the systemic "off-target" effects of radiofrequency (RF) ablation and irreversible electroporation (IRE), Bulvik et al demonstrated substantial differences in physiologic, tumorigenic, and immunologic responses between the two ablative modalities. By establishing that IRE may in fact stimulate more robust inflammatory and systemic reactions than RF at liver ablation, the authors conclude that the selection of a given ablation energy source may alter the clinical outcome depending on the circumstance-both favorably and unfavorably.

Treatment of osseous metastases using the Spinal Tumor Ablation with Radiofrequency (STAR) system

INTRODUCTION

Percutaneous ablation is an emerging, minimally invasive therapy for patients with osseous metastases who have not responded or have contraindications to radiation therapy. Goals of therapy are pain relief, and in some cases, prevention of local tumor progression. Areas covered: The epidemiology, pathophysiology, natural history, and traditional management of metastatic bone disease are reviewed. Novel features of the Spinal Tumor Ablation with Radiofrequency (STAR) System (DFINE, San Jose, CA) that facilitate treatment of osseous metastases are described, including the bipolar electrode, extensible distal tip that can be curved up to 90°, and inclusion of thermocouples that enable real-time monitoring of the ablation zone volume. Lastly, research evaluating the safety and efficacy of using this device to treat musculoskeletal metastases is summarized. Expert commentary: Although evidence supporting the efficacy of RFA for the treatment of bone metastases is limited to case series, it is a reasonable therapy when other options have been exhausted, especially given the safety and minimal morbidity of the procedure. The STAR Tumor Ablation System has expanded the anatomic scope of bone metastases that can be safely and effectively treated with percutaneous ablation.

Antiangiogenic Therapy Induces Hepatic Tumor Vascular Network Rearrangement to Receive Perfusion via the Portal Vein and Hepatic Artery

PURPOSE

Hepatic malignancies can easily develop resistance to antiangiogenic therapy, but the underlying mechanism remains poorly understood. This study explores whether antiangiogenic therapy influences the tumor vascular network and/or the vessels feeding the hepatic tumor.

METHODS

Mice implanted with Lewis lung carcinoma (LLC) cells were subcutaneously injected 3 times (once every other day starting 1 week after LLC implantation) with either an antiangiogenic agent [vascular endothelial growth factor (VEGF)-Trap] or control agent (bovine serum albumin) at a dose of 25 mg/kg before performing angiography. Hepatic arteriography and portography were performed using a vascular cast method with vascular latex.

RESULTS

Arteriography of the control-treated LLC-implanted mice showed marked staining of the mass with a prominent feeding artery, suggesting that the tumor is supplied by arterial perfusion. No significant staining was observed on portography. By contrast, 33% (n = 3/9) of the LLC-implanted mice treated with the antiangiogenic agent VEGF-Trap showed intratumoral staining during portography, indicating that these tumors received perfusion via the portal vein.

CONCLUSION

Antiangiogenic treatment can induce rearrangement of the hepatic tumor vascular network to establish communication with the portal vein. This implies that hepatic tumors can develop resistance to antiangiogenic therapy by maintaining perfusion through portal venous perfusion.

Inhibition of VEGF165/VEGFR2-dependent signaling by LECT2 suppresses hepatocellular carcinoma angiogenesis

Hepatocellular carcinoma (HCC) relies on angiogenesis for growth and metastasis. Leukocyte cell-derived chemotaxin 2 (LECT2) is a cytokine and preferentially expressed in the liver. Previous studies have found that LECT2 targets to both immune and tumor cells to suppress HCC development and vascular invasion. Although LECT2 did not affect HCC cells growth in vitro, it still suppressed HCC xenografts growth in immune-deficient mice, suggesting other cells such as stroma cells may also be targeted by LECT2. Here, we sought to determine the role of LECT2 in tumor angiogenesis in HCC patients. We found that LECT2 expression inhibited tumor growth via angiogenesis in the HCC xenograft model. Specifically, we demonstrated that recombinant human LECT2 protein selectively suppressed vascular endothelial growth factor (VEGF)₁₆₅-induced endothelial cell proliferation, migration, and tube formation in vitro and in vivo. Mechanistically, LECT2 reduced VEGF receptor 2 tyrosine phosphorylation and its downstream extracellular signal-regulated kinase and AKT phosphorylation. Furthermore, LECT2 gene expression correlated negatively with angiogenesis in HCC patients. Taken together, our findings demonstrate that LECT2 inhibits VEGF₁₆₅-induced HCC angiogenesis through directly binding to VEGFR2 and has broad applications in treating VEGF-mediated solid tumors.

Hepatic Radiofrequency Ablation-induced Stimulation of Distant Tumor Growth Is Suppressed by c-Met Inhibition

PURPOSE

To elucidate how hepatic radiofrequency (RF) ablation affects distant extrahepatic tumor growth by means of two key molecular pathways.

MATERIALS AND METHODS

Rats were used in this institutional animal care and use committee-approved study. First, the effect of hepatic RF ablation on distant subcutaneous in situ R3230 and MATBIII breast tumors was evaluated. Animals were randomly assigned to standardized RF ablation, sham procedure, or no treatment. Tumor growth rate was measured for 3½ to 7 days. Then, tissue was harvested for Ki-67 proliferative indexes and CD34 microvascular density. Second, hepatic RF ablation was performed for hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), and c-Met receptor expression measurement in periablational rim, serum, and distant tumor 24 hours to 7 days after ablation. Third, hepatic RF ablation was combined with either a c-Met inhibitor (PHA-665752) or VEGF receptor inhibitor (semaxanib) and compared with sham or drug alone arms to assess distant tumor growth and growth factor levels. Finally, hepatic RF ablation was performed in rats with c-Met-negative R3230 tumors for comparison with the native c-Met-positive line. Tumor size and immunohistochemical quantification at day 0 and at sacrifice were compared with analysis of variance and the two-tailed Student t test. Tumor growth curves before and after treatment were analyzed with linear regression analysis to determine mean slopes of pre- and posttreatment growth curves on a per-tumor basis and were compared with analysis of variance and paired two-tailed t tests.

RESULTS

After RF ablation of normal liver, distant R3230 tumors were substantially larger at 7 days compared with tumors treated with the sham procedure and untreated tumors, with higher growth rates and tumor cell proliferation. Similar findings were observed in MATBIII tumors. Hepatic RF ablation predominantly increased periablational and serum HGF and downstream distant tumor VEGF levels. Compared with RF ablation alone, RF ablation combined with adjuvant PHA-665752 or semaxanib reduced distant tumor growth, proliferation, and microvascular density. For c-Met-negative tumors, hepatic RF ablation did not increase distant tumor growth, proliferation, or microvascular density compared with sham treatment.

CONCLUSION

RF ablation of normal liver can stimulate distant subcutaneous tumor growth mediated by HGF/c-Met pathway and VEGF activation. This effect was not observed in c-Met-negative tumors and can be blocked with adjuvant c-Met and VEGF inhibitors.

Hepatocellular carcinoma: From diagnosis to treatment

Primary liver cancer is the sixth most common cancer overall and the second most common cause of cancer mortality worldwide. Hepatocellular carcinoma accounts for up to 90% of all primary hepatic malignancies and represents a major international health problem. While surgical resection and transplantation are the cornerstone of therapy in early-stage hepatocellular carcinoma, locoregional therapy and sorafenib are beneficial in those with more advanced disease or those who are not surgical candidates. At times, the integration of both surgical and locoregional therapy may be necessary. Hence, hepatocellular carcinoma requires a multidisciplinary approach to determine the most appropriate treatment as well as the timing of various treatments for optimal outcomes.

Prognostic impact of surgery and radiofrequency ablation on single nodular HCC ⩽5 cm: Cohort study based on serum HCC markers

BACKGROUND & AIMS

Serological markers of hepatocellular carcinoma (HCC) indicate its invasiveness. We aimed to investigate whether the prognostic impact of surgical resection (SR) and radiofrequency thermal ablation (RFA) on patients with single nodular HCC ⩽5cm were different regarding positive conditions of the following three HCC markers: alpha-fetoprotein (AFP); lens culinaris agglutinin-reactive fraction of AFP; and des-γ-carboxy prothrombin.

METHODS

This study reviewed 296 patients with single nodular HCC ⩽5cm with Child-Pugh grade A between 2001 and 2011 (SR, n=136; RFA, n=160). Based on positive conditions of previous HCC markers (defined as non-positive, single-positive, double-positive, and triple-positive), overall survival (OS) and prognostic factors were analyzed.

RESULTS

Five-year OS rates of SR and RFA among all patients were 70.1% and 69.8%, respectively (p=0.14). However, when stratified by the positive conditions of three HCC markers, their rates of non-, single-, double-, and triple-positive patients were 60.6%, 78.2%, 54.2%, and 75.9% in the SR group, whereas rates were 83.3%, 75.7%, 62.2%, and 47.6% in the RFA group (p values between SR and RFA of each tumor marker condition were 0.45, 0.10, 0.77, and <0.01, respectively). Multivariate analyses showed that RFA itself became an independent prognostic factor in the triple-positive group, with an odds ratio of 1.78 (95% confidence interval, 1.16-2.72).

CONCLUSIONS

Positive conditions of three HCC markers differently influenced survival rates of those who underwent SR and RFA when treating single nodular HCC ⩽5cm. RFA itself became an independent prognostic risk when all three HCC markers were positive. Preoperative evaluation of multiple HCC markers might become an index for selecting treatment modalities.

Science to Practice: The Changing Face of Local Tumor Therapies-Do We Have to Think Systemically When Treating Cancer Locally?

In this issue, Rozenblum et al ( 1 ) were able to demonstrate that radiofrequency (RF) ablation-induced liver regeneration promotes "off-target" tumorigenesis in a MDR2 knock-out mouse model of hepatocellular carcinoma (HCC) in the setting of chronic liver inflammation. In addition, the authors demonstrated that blocking liver regeneration with a c-met inhibitor might attenuate or eliminate potential tumorigenic effects. These results provide the rationale for combined therapeutic approaches of RF ablation followed by a systemic application of immunomodulatory drugs.

Proangiogenic factors in the development of HCC in alcoholic cirrhosis

Alcoholic liver disease, the most common cause of liver cirrhosis, is associated with an increased risk for hepatocellular carcinoma. Angiogenic factors have been implicated in pathophysiology of cirrhosis, and of hepatocellular carcinoma, and in particular of alcoholic liver cirrhosis, due to alcohol induced hypoxia associated with increased hepatic oxygen consumption. In one study, it was found that among genetic polymorphisms in proangiogenic factors, KDR and VEFGA may confer an increased risk of HCC, in patients with ALD. There is need of further studies of the proangiogenic factors in HCC, in order to help us define their use as prognostic markers and also as markers of response to treatment.

Low serum interleukin-6 levels as a predictive marker of recurrence in patients with hepatitis B virus related hepatocellular carcinoma who underwent curative treatment

BACKGROUND

We aimed to investigate the use of novel serum biomarkers for predicting the recurrence and survival of patients with hepatitis B virus (HBV)-related early hepatocellular carcinoma (HCC) after hepatic resection or radiofrequency ablation (RFA).

METHODS

One hundred and five patients with HBV-related HCC, who fulfilled the Milan criteria without vascular invasion and underwent hepatic resection or RFA, were followed-up for a median duration of 52months. Pretreatment serum concentrations of 16 cytokines including interleukin-6 (IL-6) were measured by using a Luminex 200 system. The measured serum cytokines and several clinical factors were analyzed retrospectively.

RESULTS

Univariate analysis showed that patients with lower pretreatment serum levels of IL-10, IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α had significantly shorter disease-free survival (DFS) than those with higher levels. Multivariate analysis revealed that a low serum IL-6 level (⩽33.00pg/mL; hazard ratio [HR]=5.39; 95% confidence interval [CI]=1.27-22.93; P=0.022), low platelet count (<100×10(9)/L; HR=2.23; 95% CI=1.28-3.89; P=0.005), and low serum albumin level (⩽3.5g/L; HR=2.26; 95% CI=1.28-3.97; P=0.005) had a negative prognostic impact on DFS. In the analysis for overall survival, a low serum platelet level (<100×10(9)/L; HR=2.80; 95% CI=1.31-5.99; P=0.008) and multiple tumor (⩾2; HR=4.05; 95% CI=1.56-10.48; P=0.004) showed a negative prognostic impact on the overall survival.

CONCLUSION

A low serum IL-6 level is, in addition to low platelet count and low serum albumin level, an independent prognostic factor for DFS in patients with HBV-related early HCC who underwent hepatic resection or RFA with curative intention.

mTOR inhibition improves fibroblast growth factor receptor targeting in hepatocellular carcinoma

BACKGROUND

Systemic therapy has proven only marginal effects in hepatocellular carcinoma (HCC) so far. The aim of this study was to evaluate the effect of targeting fibroblast growth factor receptor (FGFR) on tumour and stromal cells in HCC models.

METHODS

Human and murine HCC cells, endothelial cells (ECs), vascular smooth muscle cells (VSMCs), hepatic stellate cells (HSCs), human HCC samples, FGFR inhibitor BGJ398 and mammalian target of rapamycin (mTOR) inhibitor rapamycin were used. Effects on growth, motility, signalling and angiogenic markers were determined. In vivo subcutaneous and syngeneic orthotopic tumour models were used.

RESULTS

In tumour cells and ECs, targeting FGFR showed significant inhibitory effects on signalling and motility. Minor effects of FGFR inhibition were observed on VSMCs and HSCs, which were significantly enhanced by combining FGFR and mTOR blockade. In vivo daily (5 mg kg(-1)) treatment with BGJ398 led to a significant growth inhibition in subcutaneous tumour models, but only a combination of FGFR and mTOR blockade impaired tumour growth in the orthotopic model. This was paralleled by reduced tumour cell proliferation, vascularisation, pericytes and increased apoptosis.

CONCLUSIONS

Targeting FGFR with BGJ398 affects tumour cells and ECs, whereas only a combination with mTOR inhibition impairs recruitment of VSMCs and HSCs. Therefore, this study provides evidence for combined FGFR/mTOR inhibition in HCC.

Safety and toxicity of radioembolization plus Sorafenib in advanced hepatocellular carcinoma: analysis of the European multicentre trial SORAMIC

BACKGROUND & AIMS

The benefits of combined systemic and liver-directed treatments in inoperable intermediate- or advanced-stage hepatocellular carcinoma (HCC) have yet to be defined. This article presents the planned safety analyses for the first 40 patients randomized to radioembolization with yttrium-90 ((90) Y) resin microspheres followed by sorafenib (n = 20) or sorafenib only (n = 20) in the SORAMIC study.

METHODS

Patients identified for palliative treatment who were poor candidates for transarterial (chemo)embolization (including those failing TACE) with preserved liver function (Child-Pugh ≤B7) and ECOG performance status <2 were screened. Radioembolization was administered using a sequential lobar approach. On day 3 after the last radioembolization procedure, sorafenib 200 mg twice daily was initiated escalating to 400 mg twice daily 1 week later; a matching sorafenib dose schedule was initiated in the control arm.

RESULTS

Patients were followed up for a median of 8.3 months. Median total implanted activity of (90) Y was 1.87 (range: 0.54-2.35) GBq. Patients received a similar intensity and duration of sorafenib in the combination-treatment arm (median daily dose 614 mg over 8.5 months) and control arm (557 mg over 9.6 months). The incidence of total (196 vs. 222) and grade ≥3 (43 vs. 47) adverse events was similar in combination-treatment arm and control arm respectively (P > 0.05). No significant differences in the number of total or grade 3/4 toxicities were recorded for: total bilirubin, albumin, liver enzymes, ascites, Child-Pugh, fatigue, hand-foot skin reaction, blood pressure or diarrhoea.

CONCLUSIONS

Radioembolization followed by sorafenib appears to be as well tolerated as sorafenib alone.

Review of angiogenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumor, and its vascularity is unique and greatly different from peripheral parenchyma of liver. Afferent and efferent vessels of HCC lesions come to differ as the lesion develops. The characteristic of the flow regulates the common style of metastasis. The portal tract of the HCC lesion is the first site of the intrahepatic metastasis, because cancer cells roll into the portal vein via efferent flow. On microscopic observation, HCC displays marked vascular abnormalities, arteriogenesis and capillarization. Arteriogenesis is defined as the growth of functional collateral arteries covered with smooth muscle cells from pre-existing arteries. Sinusoidal capillarization involves the transformation of fenestrated hepatic sinusoids into continuous capillaries. Several angiogenic factors have been reported, and some of them are studied as prognostic factors or target molecules of chemotherapeutic reagents. However, the mechanism of neovascularization during HCC development is still unclear. This review discusses the characteristics of angiogenesis in HCC and known angiogenic factors of HCC.

Prognostic role of plasma vascular endothelial growth factor in patients with hepatocellular carcinoma undergoing liver transplantation

Vascular endothelial growth factor (VEGF) is pivotal in the development of hepatocellular carcinoma (HCC). Studies have demonstrated the prognostic value of circulating VEGF levels in patients undergoing liver resection or locoregional therapy (LRT) for HCC. We investigated the significance of preoperative plasma VEGF levels in patients with HCC undergoing liver transplantation (LT) at a Western transplant center. Pre-LT plasma VEGF levels were measured with an enzyme-linked immunoassay for 164 patients with HCC undergoing LT. The preoperative plasma VEGF level was correlated with clinicopathological variables and overall and recurrence-free post-LT survival. A higher pre-LT plasma VEGF level was significantly associated with pre-LT LRT (P = 0.01), multiple tumors (P = 0.02), a total tumor diameter ≥ 5 cm (P = 0.01), bilobar tumor distribution (P = 0.03), tumor vascular invasion (VI; P < 0.001), and HCC beyond the Milan criteria (P < 0.001). Patients with a plasma VEGF level > 44 pg/mL had significantly worse overall and disease-free survival than those with VEGF levels ≤ 44 pg/mL (P = 0.04 and P = 0.02, respectively). In a multivariate analysis, a plasma VEGF level > 44 pg/mL was independently associated with tumor VI (P < 0.001) and recurrence-free survival (hazard ratio = 2.12, 95% confidence interval = 1.08-4.14, P = 0.03). In conclusion, in patients with chronic end-stage liver disease and HCC, a pre-LT plasma VEGF level > 44 pg/mL may be a predictor of tumor VI and recurrence-free post-LT survival.

Ablation of hepatocellular carcinoma

Radiofrequency ablation (RFA) has gained a wide acceptance as a first-line therapeutic option for small hepatocellular carcinoma (HCC). For very early-stage HCC, despite a higher rate of local tumour progression, RFA is considered as a viable alternative to surgical resection owing to its comparable long-term survival, reduced morbidity, and greater preservation of hepatic parenchyma. For HCCs larger than 2 cm, RFA can contribute to near-curative therapy when combined with chemoembolization. RFA can be used as part of a multimodal treatment strategy for more advanced or recurrent cases, and could be a useful bridging therapy for patients who are waiting for liver transplantation. However, the use of RFA is still limited in treating large tumours and some tumours in high-risk locations. To overcome its current limitations, other ablation techniques are being developed and it is important to validate the role of other techniques for enhancing performance of ablation therapy for HCC.

Predicting recurrence following radiofrequency percutaneous ablation for hepatocellular carcinoma

Within 5 years after percutaneous ablation of hepatocellular carcinoma, roughly 70% of patients experience tumor recurrence. Relapses beyond curative options affected patients' survival. Ablation shares with resection common predictive factors of recurrence as size of the tumor, multinodularity and presence of vascular invasion. High serum α-fetoprotein level and markers of severity of underlying liver disease have also been found to be associated with recurrence and even survival. However, predictive values for recurrence of technical factors, histopathological and molecular tumors' features have been rarely studied. Few comparative studies have shown that ablation techniques impact recurrence rates. Moreover, although ablation does not allow analysis of the whole tumor, some reports suggest that biopsies allow histopathological and even molecular testing of the risk of recurrence.

The relationship of kinase insert domain receptor gene polymorphisms and clinical outcome in advanced hepatocellular carcinoma patients treated with sorafenib

Kinase insert domain receptor (KDR) is the principal receptor that promotes the pro-angiogenic action of vascular endothelial growth factor and has been the principal target of anti-angiogenic therapies. Our aim was to determine whether single-nucleotide polymorphisms (SNPs) in KDR gene are associated with clinical outcomes after first-line sorafenib therapy in advanced hepatocellular carcinoma (HCC). The SNPs in KDR were tested in 78 advanced HCC patients receiving first-line sorafenib. Correlations with clinicopathological features and survival were analyzed. Patients with AA genotype of rs1870377 and AA genotype of rs2305948 were significantly associated with a better response and longer time to progression (TTP) (5.8 vs 4.0 months, P=0.001; 5.8 vs 4.5 months, P=0.016, respectively). Patients harboring AA genotype in rs1870377 and TT/TC genotype in rs2071559 had a longer overall survival (OS) (15.0 vs 9.6 months, P=0.001; 13.0 vs 9.0 months, P=0.007, respectively). At multivariate analysis, major vascular invasion and rs1870377 were independent factors in TTP and performance status, rs1870377, and rs2071559 were independent factors in OS. Our results suggest that SNPs in KDR gene can predict clinical outcome in advanced HCC patients receiving first-line sorafenib.

Hedgehog inhibition reduces angiogenesis by downregulation of tumoral VEGF-A expression in hepatocellular carcinoma

BACKGROUND

Dysregulation and activation of Hedgehog (Hh) signalling may contribute to tumorigenesis, angiogenesis, and metastatic seeding in several solid tumours.

OBJECTIVE

We investigated the impact of Hh inhibition on tumour growth and angiogenesis using in-vitro and in-vivo models of hepatocellular carcinoma (HCC).

METHODS

The effect of the Hh pathway inhibitor GDC-0449 on tumour growth was investigated using an orthotopic rat model. Effects on angiogenesis were determined by immunohistochemical staining of von Willebrand factor antigen and by assessing the mRNA expression of several angiogenic factors. In vitro, HCC cell lines were treated with GDC-0449 and evaluated for viability and expression of vascular endothelial growth factor (VEGF). Endothelial cells were evaluated for viability, migration, and tube formation.

RESULTS

In the orthotopic HCC model, GDC-0449 significantly decreased tumoral VEGF expression which was accompanied by a significant reduction of microvessel density and tumour growth. In HCC cells, GDC-0449 had no effect on cell growth but significantly reduced target gene regulation and VEGF expression while having no direct effect on endothelial cell viability, migration, and tube formation.

CONCLUSIONS

Hh inhibition with GDC-0449 downregulates tumoral VEGF production in vitro and reduces tumoral VEGF expression, angiogenesis, and tumour growth in an orthotopic HCC model.

Genetic polymorphisms of proangiogenic factors seem to favor hepatocellular carcinoma development in alcoholic cirrhosis

OBJECTIVE

Angiogenesis has been associated with hepatic cirrhosis and hepatocellular carcinoma (HCC). Alcohol promotes liver hypoxia, a trigger of angiogenesis. We aimed to evaluate whether the frequency of three polymorphisms in hypoxia-induced factor-1α (HIF-1α), vascular endothelial growth factor A (VEGFA), and KDR (encoding vascular endothelial growth factor receptor 2) genes was higher in alcoholics presenting liver disease (ALD) and ALD patients who developed HCC.

MATERIALS AND METHODS

Functional HIF-1α 1744C/T, VEGFA 2578C/A, and KDR 1416A/T single-nucleotide polymorphisms were studied in 125 ALD patients and 88 heavy drinkers without liver disease (NLD). ALD patients were followed up to 9 years or until they died; 26 patients developed HCC.

RESULTS

ALD patients were older than NLD (56±11 vs. 50±13, P<0.001), but drank less (215±164 vs. 331±293 g/day, P<0.001). No differences were found between HIF-1α, VEGFA, or KDR allelic frequencies or genotypes, isolated or simultaneously, between ALD and NLD. In ALD patients, those who developed HCC had a higher KDR 1416T allele frequency (36 vs. 15%, P=0.004; odds ratio 2.72; 95% confidence interval 1.35-5.46). There was also a progressive increase in genotypes with one or two T alleles in patients who developed HCC: AA 50 vs. 73%, AT 35 vs. 23%, and TT 15 vs. 4% (P=0.009). The simultaneous presence of KDR 1416T and VEGFA 2578A was associated with an increased risk of HCC (odds ratio 3.088; 95% confidence interval 1.20-7.96).

CONCLUSION

Genetic polymorphisms in proangiogenic factors did not associate with the risk of ALD in heavy drinkers. However, KDR and VEFGA polymorphisms may confer an increased risk of HCC in patients with ALD.

Serum endocan as a novel prognostic biomarker in patients with hepatocellular carcinoma

Endocan is a vascular endothelium-derived factor regulated by angiogenic factors. The aim of this study was to determine whether serum endocan levels are prognostic for survival in patients with hepatocellular carcinoma (HCC). Serum endocan levels were measured in 64 HCC patients who were naïve to treatment, eight apparently healthy subjects, and 68 patients with liver cirrhosis; the latter two groups served as controls. Prognostic factors for the survival of HCC patients were examined using a Cox proportional hazards model. The median serum endocan levels were 1.145 ng/mL (range, 0.93-1.68 ng/mL) in healthy subjects, 1.93 ng/mL (range, 0.45-8.47 ng/mL) in liver cirrhosis patients, and 3.73 ng/mL (range, 0.74-10.95 ng/mL) in HCC patients (P = 0.0001). In HCC patients, elevated serum endocan levels were significantly associated with poor hepatic function (P = 0.015), a greater number of tumors (P = 0.034), and vascular invasion (P = 0.043). The median follow-up period was 23.0 months, and 33 HCC patients died during follow up. Multivariate analysis showed that serum endocan levels ≥ 2.20 ng/mL (hazard ratio 2.36, 95% confidence interval 1.22-5.36, P = 0.008) as well as elevated serum α-fetoprotein and des-γ-carboxy prothrombin levels were independent prognostic biomarkers for poor survival. The combination of serum endocan and these two additional markers was significantly predictive of worse survival (P < 0.0001). Thus, serum endocan may be a prognostic biomarker for survival in HCC patients, and the combination of serum endocan, α-fetoprotein, and des-γ-carboxy prothrombin levels can result in better prognostic stratification of these patients.

Serum VEGF level is associated with the outcome of patients with hepatocellular carcinoma: a meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is a highly vascular tumor that expresses vascular endothelial growth factor (VEGF). Various studies have evaluated the prognostic value of VEGF levels in HCC, but yielded conflicting results.

METHODS

Electronic databases updated to June 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between serum VEGF level and survival of patients with HCC. Survival data were aggregated and quantitatively analyzed.

RESULTS

We performed a meta-analysis of 11 studies that evaluated the correlation between serum VEGF level and survival in patients with HCC. Combined hazard ratios suggested that serum VEGF level had an unfavorable impact on overall survival (OS) [hazard ratio (HR) =1.88, 95% confidence interval (CI): 1.46-2.30], and disease free survival (DFS) (HR=2.27, 95% CI: 1.55-2.98) in patients with HCC. No significant heterogeneity was observed among all studies.

CONCLUSIONS

Serum high VEGF level indicates a poor prognosis for patients with hepatocellular carcinoma.

Vascular Endothelial Growth Factor (VEGF) Detection Using an Aptamer and PNA-Based Bound/Free Separation System

We have developed a bound/free separation system using a vascular endothelial growth factor (VEGF) aptamer and a peptide nucleic acid (PNA) to detect VEGF. In this system, we designed capture PNA (CaPNA), which hybridizes with the aptamer in the absence of the target protein, but does not hybridize with the aptamer in the presence of the target protein due to steric hindrance and/or stabilization of the aptamer's structure. By removing the aptamers not bound to the target protein using CaPNA immobilized beads, we can detect the target protein by measuring signals labeled with the aptamer in the supernatant. In this study, we detected VEGF using CaPNA-immobilized beads without the time-consuming washing step. This simple and rapid system can detect 25 nM of VEGF in 15 min.

Changes in plasma vascular endothelial growth factor at 8 weeks after sorafenib administration as predictors of survival for advanced hepatocellular carcinoma

Background

A new predictive biomarker for determining prognosis in patients with hepatocellular carcinoma (HCC) who receive sorafenib is required, because achieving a reduction in tumor size with sorafenib is rare, even in patients who have a favorable prognosis. Vascular endothelial growth factor (VEGF) receptor is a sorafenib target. In the current study, the authors examined changes in plasma VEGF concentrations during sorafenib treatment and determined the clinical significance of VEGF as a prognostic indicator in patients with HCC.

Methods

Plasma VEGF concentrations were serially measured in 63 patients with advanced HCC before and during sorafenib treatment. A plasma VEGF concentration that decreased >5% from the pretreatment level at 8 weeks was defined as a “VEGF decrease.” An objective tumor response was determined using modified Response Evaluation Criteria in Solid Tumors 1 month after the initiation of therapy and every 3 months thereafter.

Results

Patients who had a VEGF decrease at week 8 (n = 14) had a longer median survival than those who did not have a VEGF decrease (n = 49; 30.9 months vs 14.4 months; P = .038). All patients who had a VEGF decrease survived for >6 months, and the patients who had both a VEGF decrease and an α-fetoprotein response (n = 6) survived during the observation period (median, 19.7 months; range, 6.5-31.0 months). In univariate analyses, a VEGF decrease, radiologic findings classified as progressive disease, and major vascular invasion were associated significantly with 1-year survival; and, in multivariate analysis, a VEGF decrease was identified as an independent factor associated significantly with survival.

Conclusions

A plasma VEGF concentration decrease at 8 weeks after starting sorafenib treatment may predict favorable overall survival in patients with advanced HCC.