Des-gamma-carboxy prothrombin as an important prognostic indicator in patients with small hepatocellular carcinoma

Elevated Alfa-Fetoprotein and Des-Gamma-Carboxy Prothrombin Levels Predict Poor Outcomes After Liver Transplantation for Hepatocellular Carcinoma Beyond the Japan Criteria

AIM

The Japan criteria (Milan criteria + 5-5-500 rule) was established recently to select cirrhotic patients with hepatocellular carcinoma for liver transplantation. We evaluated factors associated with poor prognosis after liver transplantation and investigated whether a further extension of the criteria would be worthwhile.

METHODS

We retrospectively analyzed 86 patients who underwent liver transplantation for hepatocellular carcinoma at Kumamoto University Hospital since 2004; 69 patients (80.2%) met the Japan criteria (the JC^IN group), and 17 patients (19.8%) did not (the JC^OUT group).

RESULTS

The 5-year cancer-specific survival rates of the JC^IN group (92.2%) were significantly better than that of the JC^OUT group (39.2%; P < .001). In univariable analysis, alfa-fetoprotein and des-gamma-carboxy prothrombin were significant independent factors associated with cancer-specific survival rates. According to the receiver operating characteristic curves, the cutoff values of alfa-fetoprotein and des-gamma-carboxy prothrombin that predicted hepatocellular carcinoma recurrence after liver transplantation were 756 ng/mL and 1976 mAU/mL, respectively. The JC^OUT group was divided into 2 subgroups according to alfa-fetoprotein and des-gamma-carboxy prothrombin: low risk (alfa-fetoprotein level <756 ng/mL and des-gamma-carboxy prothrombin level <1976 mAU/mL) and high risk (alfa-fetoprotein level ≥756 ng/mL and/or des-gamma-carboxy prothrombin level ≥1976 mAU/mL). The 5-year cancer-specific survival rate in the low-risk group (67.5%) was significantly better than that in the high-risk group (0%; P < .001).

CONCLUSIONS

Alfa-fetoprotein levels of <756 ng/mL and des-gamma-carboxy prothrombin levels of <1976 mAU/mL may help identify cirrhotic patients with hepatocellular carcinoma who do not meet the Japan criteria but still benefit from liver transplantation.

A K-nearest Neighbor Model to Predict Early Recurrence of Hepatocellular Carcinoma After Resection

BACKGROUND AND AIMS

Patients with hepatocellular carcinoma (HCC) surgically resected are at risk of recurrence; however, the risk factors of recurrence remain poorly understood. This study intended to establish a novel machine learning model based on clinical data for predicting early recurrence of HCC after resection.

METHODS

A total of 220 HCC patients who underwent resection were enrolled. Classification machine learning models were developed to predict HCC recurrence. The standard deviation, recall, and precision of the model were used to assess the model's accuracy and identify efficiency of the model.

RESULTS

Recurrent HCC developed in 89 (40.45%) patients at a median time of 14 months from primary resection. In principal component analysis, tumor size, tumor grade differentiation, portal vein tumor thrombus, alpha-fetoprotein, protein induced by vitamin K absence or antagonist-II (PIVKA-II), aspartate aminotransferase, platelet count, white blood cell count, and HBsAg were positive prognostic factors of HCC recurrence and were included in the preoperative model. After comparing different machine learning methods, including logistic regression, decision tree, naïve Bayes, deep neural networks, and k-nearest neighbor (K-NN), we choose the K-NN model as the optimal prediction model. The accuracy, recall, precision of the K-NN model were 70.6%, 51.9%, 70.1%, respectively. The standard deviation was 0.020.

CONCLUSIONS

The K-NN classification algorithm model performed better than the other classification models. Estimation of the recurrence rate of early HCC can help to allocate treatment, eventually achieving safe oncological outcomes.

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.

Impact of local tumor lesion treatments and preoperative indicators on the survival of patients with small hepatocellular carcinomas

The prognosis for small hepatocellular carcinomas (SHCC) remains uncertain. The aim of the present study was to compare three local tumor lesion treatments and identify the prognostic factors in patients with SHCC by analyzing preoperative indicators. A retrospective study was performed using data from 206 patients with SHCC from 2006–2015. All of the patients had undergone transarterial chemoembolization (TACE) alone, TACE plus percutaneous microwave coagulation therapy (PMCT) or surgical resection (SR). The Kaplan-Meier method was used to calculate the survival rates. Multivariate analysis was conducted using Cox regression analysis. The median survival time of patients with SHCC was 27 (range, 14–49) months in the TACE group, 29.5 (range, 16–52) months in the TACE-PMCT group and 36.5 (range, 26–52) months in the SR group (P=0.091). The 1, 3 and 5-year survival rates for patients with SHCC were 82.4, 64.9 and 46.8% in the TACE group; 89.0, 72.6 and 58.3% in the TACE-PMCT group and 88.8, 72.3 and 58.6% in the SR group (P=0.181), respectively. Analysis from the Cox regression model demonstrated that preoperative α-fetoprotein (AFP; <400 ng/ml vs. ≥400 ng/ml; HR=0.548; P=0.036) was an independent predictor of the survival time of patients with SHCC. Analysis of patients with preoperative AFP levels of ≥400 ng/ml revealed that the median survival time in the SR group was 36 (range, 28.25–52) months, significantly longer than the TACE (17 months; range, 12–44 months) and TACE-PMCT group (27 months; range, 14–55 months; P=0.035). The 1, 2 and 3-year survival rates for patients with SHCC with ≥400 ng/ml AFP were: 70.8, 55.5 and 49.9% in the TACE group; 83.7, 68.0 and 60.8% in the TACE-PMCT group; and 90.9, 81.8 and 61.0% in SR group, respectively (P=0.664). However, there was no significant difference among the three groups in the survival time of patients with SHCC with <400 ng/ml preoperative AFP. The observations indicated that SR is not significantly different for overall survival time in the patients with SHCC between the two groups; this method can be employed for patients with SHCC. This was based on the median survival time of patients with ≥400 ng/ml AFP in the SR group who had a longer survival time and a higher survival rate than in the TACE and TACE-PMCT group.

Prognostic value of PIVKA-II in hepatocellular carcinoma patients receiving curative ablation: A systematic review and meta-analysis

BACKGROUND

Several studies have been conducted to evaluate the prognostic value of prothrombin induced by vitamin K absence-II (PIVKA-II) overexpression in hepatocellular carcinoma patients treated with curative ablation. However, the results remain controversial. The purpose of this meta-analysis was to explore the correlation between PIVKA-II expression and survival outcomes in these patients.

METHODS

We performed a systematic literature search in PubMed, EMBASE, Medline, Cochrane Library, and Web of Science to identify the relevant articles investigating the prognostic value of PIVKA-II in patients with hepatocellular carcinoma. Combined hazard ratios (HR) and their 95% confidence intervals (CI) for overall survival and recurrence-free survival were calculated as the analysis endpoints.

RESULTS

A total of 15 cohorts encompassing 5647 patients were included. The results indicated that elevated PIVKA-II was significantly associated with poorer overall survival (HR 1.59; 95% CI 1.40, 1.82; P < 0.001) and recurrence-free survival (HR 1.76; 95% CI 1.42, 2.17; P < 0.001). Similar results were observed in the subgroup analysis based on sample size, analytical method, treatment modality, and cut-off value.

CONCLUSIONS

This meta-analysis suggests that elevated PIVKA-II is a predictor of unfavorable overall survival and recurrence-free survival in hepatocellular carcinoma patients receiving curative ablation. More rigorous studies are warranted to confirm the clinical utility of PIVKA-II in determining hepatocellular carcinoma prognosis.

Downstaging for hepatocellular cancer: harm or benefit?

Downstaging of hepatocellular carcinoma (HCC) to enable liver transplantation has become an area of intense interest and research. It may allow a curative option in patients outside widely accepted transplantation criteria, with outcomes that, in some studies, are comparable to transplantation for patients within criteria. There have been conflicting opinions on the best downstaging protocols, criteria for downstaging eligibility and for assessment of response. We therefore aimed to review the literature and evidence for downstaging, as well as considering its drawbacks.

CONCLUSION

Pooled analyses have suggested success in down staging in about half of patients treated, but with higher recurrence rates than patients initially within transplantation criteria. Studies with strict inclusion criteria and mandatory waiting time before transplantation reported survival equivalent to patients who did not require downstaging. In carefully selected patients, there is a role for down staging to provide the chance of transplantation and cure, with acceptable outcomes. Further multi center, well-designed studies are required to clarify who will mostly benefit. Until such data is available, downstaging criteria should be stated within transplantation programs and relevant decisions should be discussed by multidisciplinary teams.

PIVKA-II is a useful tool for diagnostic characterization of ultrasound-detected liver nodules in cirrhotic patients

Protein induced by vitamin K absence-II (PIVKA-II) is a potential screening marker for hepatocellular carcinoma (HCC). Limited data are available about its utility in discriminating neoplastic from regenerative nodules at ultrasonography (US) evaluation in cirrhotic patients. Aim of this study was to investigate the diagnostic utility of PIVKA-II in cases showing liver nodules of uncertain diagnosis at US.Ninety cirrhotics with US evidence of liver nodule(s) were enrolled. All patients underwent blood sampling within 1 week of US and were thereafter followed up. HCC was confirmed in 40/90 cases, and in all cases it was in a very early/early stage. All sera were tested for PIVKA-II and alpha-fetoprotein (AFP) at the end of follow-up. PIVKA-II at a cut off of 60 mAU/mL was significantly associated with HCC at both univariate and multivariate analysis (P = .016 and P = .032, respectively). AFP at a cut off of 6.5 ng/mL was not associated with HCC at univariate analysis (P = .246). ROC curves showed that PIVKA-II had 60% sensitivity, 88% specificity, 80% positive predictive value (PPV), and 73% negative predictive value (NPV), whereas AFP had 67% sensitivity, 68% specificity, 63% PPV, and 72% NPV. AUROC curves showed that the combination of both biomarkers increased the diagnostic accuracy for HCC (AUC 0.76; sensitivity 70%, specificity 94%, PPV 91%, and NPV 79%).In conclusion, PIVKA-II is a useful tool for the diagnostic definition of US-detected liver nodules in cirrhotic patients, and it provides high diagnostic accuracy for HCC when combined with AFP.

Preoperative prognostic values of α-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) in patients with hepatocellular carcinoma for living donor liver transplantation

BACKGROUND

Adult living donor liver transplantation (LDLT) is one of the best treatments for hepatocellular carcinoma (HCC). However, when recurrence of HCC after LDLT occurs, the prognosis is poor because of rapid progression. Preoperative level of α-fetoprotein (AFP) and protein induced by vitamin K antagonist-II (PIVKA-II) reportedly correlate with recurrence of HCC after LDLT.

METHODS

We examined AFP and PIVKA-II preoperatively as predictors of HCC recurrence in 461 patients who underwent LDLT using right liver graft for HCC from May 2007 to December 2013.

RESULTS

Among these, 77 patients (16.7%) who experienced recurrence were retrospectively reviewed. Multivariate analysis revealed tumor size >5 cm, AFP >150 nag/mol and PIVKA-II >100 maul/mol as significant independent risk factors for recurrence. The median time to recurrence was 10 months. The median survival time after recurrence was 26 months, and the 1-, 3- and 5-year survival rates after recurrence were 80.5%, 58%, and 28.3% respectively.

CONCLUSIONS

Preoperatively, not only morphology of the tumor but also AFP and PIVKA-II levels can offers important information for the recurrence after LDLT for HCC. Thus, combination of tumor markers might be used for expansion of pre-existing strict selection criteria of liver transplantation for HCC.

Hepatocellular carcinoma beyond Milan criteria: Management and transplant selection criteria

Liver transplantation (LT) for hepatocellular carcinoma (HCC) has been established as a standard treatment in selected patients for the last two and a half decades. After initially dismal outcomes, the Milan criteria (MC) (single HCC ≤ 5 cm or up to 3 HCCs ≤ 3 cm) have been adopted worldwide to select HCC patients for LT, however cumulative experience has shown that MC can be too strict. This has led to the development of numerous expanded criteria worldwide. Morphometric expansions on MC as well as various criteria which incorporate biomarkers as surrogates of tumor biology have been described. HCC that presents beyond MC initially can be downstaged with locoregional therapy (LRT). Post-LRT monitoring aims to identify candidates with favorable tumor behavior. Similarly, tumor marker levels as response to LRT has been utilized as surrogate of tumor biology. Molecular signatures of HCC have also been correlated to outcomes; these have yet to be incorporated into HCC-LT selection criteria formally. The ongoing discrepancy between organ demand and supply makes patient selection the most challenging element of organ allocation. Further validation of extended HCC-LT criteria models and pre-LT treatment strategies are required.

Considerations regarding current diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma is a major health issue, ranked the fifth most common tumor and currently being responsible for a third of the cancer-related deaths globally, with an ever-increasing number of fatalities. Current advances in contrast-enhanced imaging techniques such as contrast-enhanced ultrasonography, multi-detector computed tomography and diffusion-weighted magnetic resonance imaging are improving the rate of hepatocellular carcinoma diagnosis. Contrast-enhanced ultrasonography has widely become the first choice in liver tumor assessment, as it is faster, simpler and safer than other forms of diagnostic imaging. On the other hand, cross sectional computed tomography is frequently employed when a hepatic formation is suspected of malignancy and allows a more accurate characterization of lesions through multiphasic multi-detector computed tomography technology. Diffusion weighted magnetic resonance imaging represents another addition to the wide range of diagnostic and prognostic techniques available for patients with hepatocellular carcinoma and is currently regarded as one of the best tools for the characterization of these lesions. Furthermore, groundbreaking biomarkers for hepatocellular carcinoma are being discovered, although alpha-fetoprotein remains one of the most frequently used serum test in the early stages. Nonetheless, further advances are required for the detection of small liver carcinomas.

Biological markers of hepatocellular carcinoma for use as selection criteria in liver transplantation

The Milan criteria (MC) have been widely accepted as an effective way of selecting patients with early-stage hepatocellular carcinoma (HCC) for curative liver transplantation (LT). However, since a substantial subset of HCC patients exists that is beyond the MC but with the potential for good outcomes after LT, several institutions have recently proposed new extended criteria. To explore optimal criteria that can reasonably predict the risk of recurrence, it is considered that new markers of biological behavior are needed in addition to morphological tumor size and number. Several promising candidates for such biological markers have been reported, including serum tumor markers such as alpha-fetoprotein and des-gamma-carboxy prothrombin, inflammatory markers such as C-reactive protein and neutrophil-to-lymphocyte ratio, response to pre-transplant treatments for bridging therapy or down-staging, and fluorine-18-fluorodeoxyglucose positron emission tomography. However, the role of these biological markers in patient selection criteria for LT has yet to be clarified. This review article aims to summarize the results of recent reported studies and to display perspectives for the establishment of optimal criteria that incorporate such biological markers.

Prognostic values of vascular endothelial growth factor and matrix metalloproteinase-2 in hepatocellular carcinoma after radiotherapy

OBJECTIVES

Hepatocellular carcinoma (HCC) is a highly vascularized tumor. In this study, we investigated the prognostic and predictive values of proangiogenic factors in HCC patients receiving radiotherapy.

METHODS

Between September 2008 and December 2009, a total of 50 patients treated with radiotherapy were prospectively enrolled in this study. Serum and urine samples were collected <1 week before and after radiotherapy.

RESULTS

After completion of radiotherapy, serum vascular endothelial growth factor (VEGF)/platelet (Plt) levels were significantly increased (p < 0.01). Patients who experienced hepatic tumor recurrence outside the radiation field showed higher VEGF-A/Plt levels before and after radiotherapy than patients who did not (p = 0.04), whereas patients who had hepatic tumor recurrence inside the radiation field showed significantly higher matrix metalloproteinase (MMP)-2 levels after radiotherapy (p = 0.04). On multivariate analyses, a high level of either VEGF/Plt or MMP-2 (≥median) before radiotherapy was a significant independent prognostic factor for a worse progression-free survival (p = 0.04).

CONCLUSIONS

In HCC patients receiving radiotherapy, levels of VEGF/Plt and MMP-2 before radiotherapy can be useful to predict treatment outcome. This study also suggests the necessity of anti-angiogenic therapy, such as sorafenib, since radiotherapy increases VEGF/Plt levels, and higher levels of VEGF/Plt are associated with a poor outcome.

Evaluation methods for pretransplant oncologic markers and their prognostic impacts in patient undergoing living donor liver transplantation for hepatocellular carcinoma

Tumor markers [alpha-fetoprotein (AFP) or des-gamma-carboxyprothrombin (DCP)] and neutrophil/lymphocyte ratio (NLR) reportedly correlate with long-term outcomes for hepatocellular carcinoma (HCC). However, no standardized method has been established for evaluating the pretransplant data. One hundred and twenty-four patients who underwent living donor liver transplantation (LDLT) were retrospectively reviewed. The best predictive parameters for tumor recurrence were maximum values for AFP or DCP and 90-day mean values for NLR, respectively, and multivariate analysis confirmed these values were correlated with tumor recurrence. However, receiver operating characteristic analysis revealed that discriminative powers were sufficient only in maximum AFP [area under the curve (AUC) 0.88, P < 0.001] and maximum DCP (AUC 0.76, P < 0.001), while mean NLR was less predictive (AUC 0.62, P = 0.20). When incorporating AFP and DCP to the Tokyo criteria (≤5 tumors with each tumor ≤ 5 cm), the presence of at least two of the following factors: (i) beyond the Tokyo criteria, (ii) AFP>250 ng/ml, and (iii) DCP > 450 mAu/ml (>450 ng/ml), was correlated with a worse 5-year disease-free survival rate (20.0% vs. 96.8%, P < 0.001) and 5-year overall survival rate (20.0% vs. 84.0%, P < 0.001). The prognosis of patients undergoing LDLT for HCC strongly relies on maximum AFP or DCP values before transplantation, while the prognostic impact of NLR is limited.

Increased concentrations of apo A-I and apo A-II fragments in the serum of patients with hepatocellular carcinoma by magnetic beads-assisted MALDI-TOF mass spectrometry

OBJECTIVES

Recent advances in sophisticated technologies in proteomics should provide promising ways to discover novel markers for hepatocellular carcinoma (HCC) in the early diagnosis.

METHODS

Serum peptide and protein profiling was conducted by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Profiling was carried out in a training set of 16 patients with HCC and a testing set of 15 patients with cirrhosis without HCC. All the patients were hepatitis C virus positive. Candidate peaks were processed to partial purification, followed by protein identification by amino acid sequence analysis. Immunoprecipitation was conducted to confirm the protein identity.

RESULTS

Partial purification and protein identification revealed that one peak that was up-regulated in HCC sera both in the training and the testing sets was a fragment of apolipoprotein A-I (apo A-I). Immunoprecipitation confirmed this result.

CONCLUSIONS

MALDI-TOF MS analysis revealed that apo A-I is a potential novel serum marker of HCC. Combination of these pretreatments and the current magnet bead-assisted MALDI-TOF MS will further enhance the efficiency of biomarker discovery for HCC.

Des-gamma-carboxy prothrombin identified by P-11 and P-16 antibodies reflects prognosis for patients with hepatocellular carcinoma

BACKGROUND AND AIMS

Serum des-γ-carboxy prothrombin (DCP) is an established tumor marker in patients with hepatocellular carcinoma (HCC), which can be identified by using MU-3 antibody. The MU-3 antibody mainly reacts with the 9-10 glutamic acid residues of DCP (conventional DCP). Since other variants of DCP with fewer glutamic acid residues can be detected using P-11 and P-16 antibodies (code name: NX-PVKA), we examined the clinical characteristics associated with NX-PVKA, and whether NX-PVKA is a useful measure in HCC patients.

METHODS

Participants comprised 197 HCC patients admitted to our hospital between 2001 and 2010. NX-PVKA, conventional DCP, alpha-fetoprotein, and L3 fraction of alpha-fetoprotein were measured prior to initiation of HCC treatment.

RESULTS

Of the tumor markers assessed, NX-PVKA was the only significant predictor of prognosis (hazard ratio, 81.32; P < 0.0001). Patients with NX-PVKA level ≥ 100 mAU/mL showed significantly lower survival rates (P < 0.0001). NX-PVKA level was also significantly associated with platelet count, prothrombin time, C-reactive protein, sex, maximum tumor size, number of nodules, and portal venous invasion by HCC. Finally, using NX-PVKA level and other clinical parameters, we established a prognostic model to estimate patient survival time.

CONCLUSIONS

NX-PVKA offers the best marker of tumor prognosis among HCC patients, and is strongly associated with tumor factors and hepatic functional reserve. NX-PVKA could be useful for clinical evaluation of tumor severity, as well as the estimated duration of survival among patients with HCC.

Impact of low versus conventional doses of chemotherapy during transcatheter arterial chemo-embolization on serum fibrosis indicators and survival of liver cancer patients

OBJECTIVES

To explore the impact of low- vs conventional-dose chemotherapy via transcatheter arterial chemo-embolization (TACE) on serum fibrosis indicators and treatment efficacy of hepatocellular cancer patients (HCC).

MATERIALS AND METHODS

Patients fulfilling the eligibility criteria were assigned to TACE in Group A (with low-dose chemotherapy) or Group B (conventional-dose chemotherapy). Four serum fibrosis related indicators, hyaluronic acid(HA), human pro-collagen type-III (hPC-III), laminin (LN), and collagen type-IV(IV-C) before TACE were compared with the values 7 days after TACE. The response rate and survival time were also compared between the two groups.

RESULTS

Fifty patients with HCC were enrolled in this study, including 25 in Group A and 25 in Group B. No significant differences were detected between the two groups in the four indicators before TACE. After TACE, the value of the four serum indicators increased significantly in Group B. However, no significant differences regarding these four indicators were found in Group A after TACE. Significant differences were demonstrated between the two groups after TACE, but median survival time and 1 or 2 year overall survival rates did not differ (P>0.05).

CONCLUSIONS

Low-, compared with conventional-dose chemotherapy exerts the same impact on the variation of fibrosis related indicators and has no influence on median survival time and survival rate after TACE in HCC patients.

Recombinant snake venom prothrombin activators

Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need for additional cofactors, but does not discriminate non-carboxylated prothrombin from biologically active γ-carboxylated prothrombin. Here we report that recombinant trocarin and oscutarin could not efficiently generate thrombin without additional protein co-factors. We confirm that both trocarin and oscutarin are similar to human coagulation Factor X (FX), explaining the need for additional cofactors. Sequencing of a genomic fragment containing 7 out of the 8 exons coding for oscutarin further confirmed the similarity to human FX.

Hepatocellualar carcinoma serum markers

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in some areas of the world. In most cases, HCC is diagnosed at a late stage. Therefore, the prognosis of patients with HCC is generally poor. The recommended screening strategy for patients with cirrhosis includes the determination of serum α-fetoprotein (AFP) levels and an abdominal ultrasound every 6 months to detect HCC at an earlier stage. AFP, however, is a marker characterized by poor sensitivity and specificity, and abdominal ultrasound is highly dependent on the operator's experience. In addition to AFP, Lens culinaris agglutinin-reactive AFP (AFP-L3), des-γ-carboxy prothrombin (DCP), glypican-3 (GPC-3), osteopontin (OPN), and several other biomarkers (such as squamous cell carcinoma antigen-immunoglobulin M complexes [SCCA-IgM], alpha-1-fucosidase [AFU], chromogranin A [CgA], human hepatocyte growth factor, insulin-like growth factor) have been proposed as markers for the early detection of HCC. For these markers, we describe the mechanisms of production, and their diagnostic and prognosis roles. None of them is optimal; however, when used together, their sensitivity in detecting HCC is increased. Recent research has shown that some biomarkers have mitogenic and migratory activities in the angiogenesis of HCC and are a factor of tumor growth.

Transcatheter arterial chemoembolization: history for more than 30 years

Transcatheter arterial chemoembolization (TACE) is a minimally invasive technique to treat liver tumors, particularly hepatocellular carcinoma (HCC). TACE was used in early times to treat liver tumor patients with emergencies caused by symptomatic humoral hypercalcemia and develops gradually from the procedures of diagnostic angiography and transcatheter injection of agents and is in particular performed in the treatment of HCC. Since the beginning of this century, TACE has been used extensively in the palliative treatment of unresectable HCC. In recent years, it is indicated in selected patients with early-stage HCC. This review introduces the evolution of TACE for more than 30 years, its role in comprehensive treatment of HCC, the tendency of its refinement in future, and the combination use of TACE with other local ablative methods for the curative result of HCC.

Expression and characterization of recombinant ecarin

The snake venom protease ecarin from Echis carinatus was expressed in stable transfected CHO-S cells grown in animal component free cell culture medium. Recombinant ecarin (r-ecarin) was secreted from the suspension adapted Chinese Hamster Ovary (CHO-S) host cells as a pro-protein and activation to the mature form of r-ecarin occurred spontaneously during continued incubation of the cell culture at 37 °C after death of the host cells. Maximal ecarin activity was reached 7 days or more after cell culture viability had dropped to zero. The best producing CHO-S clone obtained produced up to 7,000 EU ecarin/litre in lab scale shaker cultures. The conversion of different concentrations of both prothrombin and prethrombin-2 as substrates for native and r-ecarin were examined with a chromogenic thrombin substrate. At low concentrations both these proteins were converted into thrombin by the two ecarin preparations with comparable rates. However, with prothrombin concentrations above 250 nM r-ecarin apparently had a two times higher turnover than native ecarin, consistent with the observed rapid complete conversion of prothrombin into thrombin by r-ecarin. With r-ecarin a K (m) value of 0.4 μM prethrombin-2 was determined but only a rough estimate could be made of the K (m) for prothrombin of 0.9 μM. In conclusion, r-ecarin was identified as a promising candidate for replacement of native ecarin in assays utilizing conversion of prothrombin to thrombin.

Expression and characterization of recombinant ecarin

The snake venom protease ecarin from Echis carinatus was expressed in stable transfected CHO-S cells grown in animal component free cell culture medium. Recombinant ecarin (r-ecarin) was secreted from the suspension adapted Chinese Hamster Ovary (CHO-S) host cells as a pro-protein and activation to the mature form of r-ecarin occurred spontaneously during continued incubation of the cell culture at 37 °C after death of the host cells. Maximal ecarin activity was reached 7 days or more after cell culture viability had dropped to zero. The best producing CHO-S clone obtained produced up to 7,000 EU ecarin/litre in lab scale shaker cultures. The conversion of different concentrations of both prothrombin and prethrombin-2 as substrates for native and r-ecarin were examined with a chromogenic thrombin substrate. At low concentrations both these proteins were converted into thrombin by the two ecarin preparations with comparable rates. However, with prothrombin concentrations above 250 nM r-ecarin apparently had a two times higher turnover than native ecarin, consistent with the observed rapid complete conversion of prothrombin into thrombin by r-ecarin. With r-ecarin a K (m) value of 0.4 μM prethrombin-2 was determined but only a rough estimate could be made of the K (m) for prothrombin of 0.9 μM. In conclusion, r-ecarin was identified as a promising candidate for replacement of native ecarin in assays utilizing conversion of prothrombin to thrombin.

Sorafenib and hepatic arterial infusion chemotherapy for unresectable advanced hepatocellular carcinoma: A comparative study

Sorafenib is a kinase-targeted drug that has high efficacy for advanced hepatocellular carcinoma (HCC). The aim of the present study was to determine whether sorafenib is more effective than hepatic arterial infusion chemotherapy (HAIC) for HCC. Twenty patients treated with sorafenib (sorafenib group) initiated at 800 mg/day and 45 patients treated with HAIC (HAIC group) for unresectable Child-Pugh A advanced HCC were investigated retrospectively. The treatment effect was assessed using the Response Evaluation Criteria in Solid Tumors (RECIST). As a result, the overall response rate was significantly lower in the sorafenib group than in the HAIC group (P=0.03), while the disease control and survival rates did not differ between the two groups. In the sorafenib group, treatment was discontinued in 19 patients, including 12 due to side effects. In subgroups of patients treated with sorafenib, the survival rate was significantly lower in patients (n=11) administered sorafenib for <60 days compared to those (n=9) treated for ≥60 days. A shorter treatment period (<60 days) was an independent risk factor for unfavorable survival [hazard ratio (HR), 3.34; 95% confidence interval (CI), 1.45-7.66 vs. HAIC], while survival in patients treated with sorafenib for ≥60 days did not differ from those treated with HAIC (HR, 0.79; 95% CI, 0.27-2.34). In conclusion, the disease control and survival rates of patients treated with sorafenib for advanced HCC were comparable to such rates in patients treated with HAIC. However, the prognosis was poor when long-term sorafenib treatment was not possible due to side effects, demonstrating the importance of patient selection for sorafenib treatment.

Clinical and molecular insights into the hepatocellular carcinoma tumour marker des-γ-carboxyprothrombin

Des-γ-carboxyprothrombin (DCP) is known as a tumour marker for hepatocellular carcinoma (HCC). Various tumour markers have been developed for serological diagnosis of cancers, including HCC, in order to increase the survival rate of cancer patients. The currently recommended combined testing of DCP and α-fetoprotein (AFP) or Lens culinaris agglutinin-reactive fraction of α-fetoprotein has been established to diagnose HCC. This combined testing using several tumour markers helps to increase the sensitivity of diagnosis of HCC, thus significantly increasing the clinical usefulness of DCP. The excessive production of DCP may be related to worse tumour behaviour, such as the presence of vascular invasion and intrahepatic metastasis of HCC cells. A high level of DCP was suggested to be useful as one of the factors in new recipient selection criteria of liver transplantation. The clinical use of DCP, therefore, might play a vital role in predicting tumour behaviour in patients with HCC. That said, the basic mechanism of DCP production has not been fully clarified. Various factors such as vitamin K(2) and γ-glutamyl carboxylase may contribute to the production of DCP and have a complex relationship. Moreover, recent studies have revealed that DCP functions as a growth factor and might play significant roles in cancer progression. Thus, DCP represents a potential target of drug discovery to establish new chemotherapeutic strategy for HCC. However, various issues have to be resolved to construct a novel therapy for HCC-targeting DCP. Innovation is required to make further progress in examining DCP.

Strategy of treatment for hepatocellular carcinomas with vascular infiltration in patients undergoing hepatectomy

BACKGROUND AND OBJECTIVES

Vascular infiltration (VI) is an important prognostic factor for hepatocellular carcinoma (HCC) and predictive parameters are necessary to preoperatively decide treatment strategies in patients with HCC.

METHODS

Relationships between presence and degree of VI in the portal and hepatic veins and bile duct, and post-hepatectomy survival were examined in 271 HCC patients who underwent hepatectomy.

RESULTS

VI was observed in 81 patients (30%). Disease-free and overall survival rates was significantly lower in patients with VI than in patients without VI, and became poorer according to the degree of infiltration (P < 0.01). Multiple, increased size, non-meeting of Milan criteria, irregular macroscopic findings and increased PIVKA-II levels were associated with degree of VI in portal vein (P < 0.01). Increased size and increased PIVKA-II level were associated with degree of VI in hepatic vein (P < 0.05). Non-meeting of Milan criteria was associated with degree of infiltration in bile duct (P = 0.034). Survival was significantly better following anatomical resection than with non-anatomical resection and, furthermore, survival was better with surgical margins >5 mm than with shorter margins in patients who underwent non-anatomical resection.

CONCLUSION

Adequate extent of operative procedures, but not limited resection with short margins, is useful when predictive parameters associated with VI are observed.

Significance of des-gamma-carboxy prothrombin in selection criteria for living donor liver transplantation for hepatocellular carcinoma

Des-gamma-carboxy prothrombin (DCP) levels reportedly correlate with histological features of hepatocellular carcinoma (HCC). We examined serum DCP as a predictor of HCC recurrence in 144 patients who underwent living donor liver transplantation. Receiver operating characteristics (ROC) analysis revealed superiority of DCP and AFP over preoperative tumor size or number for predicting recurrence. Multivariate analysis revealed tumor size >5 cm, > or =11 nodules, and DCP >400 mAU/mL as significant independent risk factors for recurrence. Incidence of microvascular invasion (62% vs. 27%, p = 0.0003) and poor differentiation (38% vs. 16%, p = 0.0087) were significantly higher for patients with DCP >400 mAU/mL than for patients with DCP < or =400 mAU/mL. In ROC analysis for patients with < or =10 nodules all < or =5 cm to predict recurrence, area under the curve was much higher for DCP than for AFP (0.84 vs. 0.69). Kyoto criteria were thus defined as < or =10 nodules all < or =5 cm, and DCP < or =400 mAU/mL. The 5-year recurrence rate for 28 patients beyond-Milan but within-Kyoto criteria was as excellent as that for 78 patients within-Milan criteria (3% vs. 7%). The preoperative DCP level offers additional information regarding histological features, and thus can greatly improve patient selection criteria when used with tumor bulk information.

Preoperative prediction of poorly differentiated components in small-sized hepatocellular carcinoma for safe local ablation therapy

BACKGROUND

Poorly differentiated hepatocellular carcinoma (HCC) has a malignant potential such as frequent microvascular invasion even if the tumor is smaller than 3 cm in diameter. The aim of this study was to clarify the preoperative predictors of poorly differentiated HCC for safe local ablation therapy.

METHODS

Sixty-six patients underwent a hepatic resection for solitary small-sized HCC (<or=3 cm) were included in this study. According to the postoperative histological examination, the patients were divided into a "poorly differentiated group" (n = 17) and a "well/moderately differentiated group" (n = 49). This study investigated the clinicopathological factors and imaging findings, and elucidated the predictive factors of the poorly differentiated type.

RESULTS

In a univariate analysis, serum hepatitis B surface antigen positive, hepatitis C virus antibody negative, alpha-fetoprotein level, des-gamma-carboxy prothrombin level, and a high contrast-to-noise ratio (CNR) in T2-weighted MR imaging were significantly associated with the poorly differentiate type. In a multivariate analysis, a high CNR in T2-weighted MR imaging was the only independent predictor of the poorly differentiated type. In the postoperative pathological findings, portal vein invasion and intrahepatic metastasis were significantly frequent in the poorly differentiated group.

CONCLUSIONS

The CNR in T2-weighted MR imaging is a useful tool to predict poorly differentiated HCC preoperatively.

Des-gamma-carboxy prothrombin increases the expression of angiogenic factors in human hepatocellular carcinoma cells

AIMS

Des-gamma-carboxyl prothrombin (DCP) is a serum protein produced by hepatocellular carcinoma (HCC) cells. The aim of this study was to evaluate the angiogenic activity of DCP in HCC cells.

MAIN METHODS

The proliferation of HCC cells was measured by 3-[4, 5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. The growth of HCC cells was also evaluated in vivo by using the xenografts in nude mice. The enzyme-linked immunosorbent assay (ELISA) was employed to measure the levels of angiogenic factors in supernatant of cell culture. The expression of angiogenic factors was examined by Western blot analysis and immunohistochemical staining.

KEY FINDINGS

DCP displayed the stimulation of HCC cell growth in a dose (5-80 ng/ml) and time (24-96 h) dependent manner. The increase of cell growth was also observed in nude mice bearing well-established, palpable HepG2 and SMMC-7721 xenografts after 2 weeks administration of DCP. HCC cell growth was accompanied by the elevated levels of angiogenic factors. The levels of vascular endothelial growth factor (VEGF), transforming growth factor-alpha (TGF-alpha) and basic fibroblast growth factor (bFGF) in supernatant of SMMC-7721 cells were increased from 47, 126, and 60 pg/10(6) cells/24 h to 400, 208, and 298 pg/10(6) cells/24 h, respectively, after 72 h incubation with 80 ng/ml of DCP. The results of Western blot analysis and immunohistochemical staining of HCC xenografts also showed the significant increase of VEGF, TGF-alpha, and bFGF in HCC cells.

SIGNIFICANCE

These results provide the information that DCP is a type of growth factor in progression of HCC.