Tenyu Motoyama

Metformin, a Diabetes Drug, Eliminates Tumor-Initiating Hepatocellular Carcinoma Cells

Metformin has been widely used as an oral drug for diabetes mellitus for approximately 60 years. Interestingly, recent reports showed that metformin exhibited an anti-tumor action in a wide range of malignancies including hepatocellular carcinoma (HCC). In the present study, we investigated its impact on tumor-initiating HCC cells. Metformin suppressed cell growth and induced apoptosis in a dose-dependent manner. Flow cytometric analysis showed that metformin treatment markedly reduced the number of tumor-initiating epithelial cell adhesion molecule (EpCAM)+ HCC cells. Non-adherent sphere formation assays of EpCAM+ cells showed that metformin impaired not only their sphere-forming ability, but also their self-renewal capability. Consistent with this, immunostaining of spheres revealed that metformin significantly decreased the number of component cells positive for hepatic stem cell markers such as EpCAM and α-fetoprotein. In a xenograft transplantation model using non-obese diabetic/severe combined immunodeficient mice, metformin and/or sorafenib treatment suppressed the growth of tumors derived from transplanted HCC cells. Notably, the administration of metformin but not sorafenib decreased the number of EpCAM+ cells and impaired their self-renewal capability. As reported, metformin activated AMP-activated protein kinase (AMPK) through phosphorylation; however its inhibitory effect on the mammalian target of rapamycin (mTOR) pathway did not necessarily correlate with its anti-tumor activity toward EpCAM+ tumor-initiating HCC cells. These results indicate that metformin is a promising therapeutic agent for the elimination of tumor-initiating HCC cells and suggest as-yet-unknown functions other than its inhibitory effect on the AMPK/mTOR pathway.

Efficacy of Sorafenib in Intermediate-Stage Hepatocellular Carcinoma Patients Refractory to Transarterial Chemoembolization

Objective: We compared the benefits of sorafenib therapy with continued transarterial chemoembolization (TACE) in TACE-refractory patients with intermediate-stage hepatocellular carcinoma (HCC). Methods: This retrospective study reviewed intermediate-stage HCC patients who underwent the first TACE. Patients were defined as TACE-refractory and divided into two cohorts: (1) patients who switched from TACE to sorafenib and (2) those who continued TACE. We evaluated the patient overall survival (OS) and time to disease progression (TTDP; the time patients reached Child-Pugh C or developed advanced-stage HCC). Results: A total of 509 patients with HCC underwent TACE. Of 249 intermediate-stage HCC patients undergoing the first TACE, 122 were deemed refractory. At the time they were identified as refractory, 20 patients converted to sorafenib, whereas 36 patients continued TACE. We excluded patients with Child-Pugh scores of ≥8, those with advanced-stage HCC, those who had undergone hepatic arterial infusion chemotherapy or other systemic therapy, and those treated with best supportive care alone. The median TTDP and OS were 22.3 and 25.4 months, respectively, in the conversion group, and 7.7 and 11.5 months, respectively, in the continued group (p = 0.001 and p = 0.003, respectively). Conclusions: It is possible that sorafenib conversion might prolong OS and TTDP in TACE-refractory patients with intermediate-stage HCC.

Disulfiram Eradicates Tumor-Initiating Hepatocellular Carcinoma Cells in ROS-p38 MAPK Pathway-Dependent and -Independent Manners

Tumor-initiating cells (TICs) play a central role in tumor development, metastasis, and recurrence. In the present study, we investigated the effect of disulfiram (DSF), an inhibitor of aldehyde dehydrogenase, toward tumor-initiating hepatocellular carcinoma (HCC) cells. DSF treatment suppressed the anchorage-independent sphere formation of both HCC cells. Flow cytometric analyses showed that DSF but not 5-fluorouracil (5-FU) drastically reduces the number of tumor-initiating HCC cells. The sphere formation assays of epithelial cell adhesion molecule (EpCAM)+ HCC cells co-treated with p38-specific inhibitor revealed that DSF suppresses self-renewal capability mainly through the activation of reactive oxygen species (ROS)-p38 MAPK pathway. Microarray experiments also revealed the enrichment of the gene set involved in p38 MAPK signaling in EpCAM+ cells treated with DSF but not 5-FU. In addition, DSF appeared to downregulate Glypican 3 (GPC3) in a manner independent of ROS-p38 MAPK pathway. GPC3 was co-expressed with EpCAM in HCC cell lines and primary HCC cells and GPC3-knockdown reduced the number of EpCAM+ cells by compromising their self-renewal capability and inducing the apoptosis. These results indicate that DSF impaired the tumorigenicity of tumor-initiating HCC cells through activation of ROS-p38 pathway and in part through the downregulation of GPC3. DSF might be a promising therapeutic agent for the eradication of tumor-initiating HCC cells.

Sustained virologic response achieved after curative treatment of hepatitis C virus-related hepatocellular carcinoma as an independent prognostic factor.

Whether an antiviral interferon (IFN)‐based therapy (IBT) after curative treatment of hepatocellular carcinoma (HCC) improves the prognosis in patients with hepatitis C virus (HCV)‐related HCC remains to be elucidated.

Effect of Previous Interferon-based Therapy on Recurrence after Curative Treatment of Hepatitis C Virus-related Hepatocellular Carcinoma

Previous reports have shown that interferon (IFN)-based therapy decreases the risk of development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C virus (HCV) infection. However, it remains to be fully elucidated whether elimination of HCV by IFN-based therapy inhibits HCC recurrence after curative treatment, such as surgical resection and local ablation therapies. In this study, we aimed to clarify the influence of a sustained virological response (SVR) after IFN-based therapy on recurrence and survival after curative treatment of HCC. Fifty-one patients who underwent curative treatment of HCV-related HCC after receiving IFN-based therapy were analyzed retrospectively. They were classified into SVR (N = 14) and non-SVR groups (N = 37). In the SVR group, serum levels of aspartate aminotransferase and alanine aminotransferase, the indocyanine green retention rate at 15 min, and the percentages of patients with liver cirrhosis and HCV serotype 1 were significantly lower, whereas serum albumin level and platelet count were significantly higher upon HCC occurrence. Recurrence-free survival (RFS) for the first recurrence was significantly higher in the SVR group (P < 0.01). Multivariate analysis showed that SVR at initial HCC treatment (P < 0.01) and multiple tumors (P < 0.01) are prognostic factors for RFS. Moreover, RFS for the second recurrence showed a similar trend to that for the first recurrence. In conclusion, patients who underwent IFN-based therapy before initial curative treatment of HCC had a favorable clinical outcome compared with non-SVR patients.

A prognostic score for patients with intermediate-stage hepatocellular carcinoma treated with transarterial chemoembolization.

Background Intermediate-stage hepatocellular carcinoma (HCC), defined according to the Barcelona Clinic Liver Cancer (BCLC) staging system, is a heterogeneous condition with variable clinical benefits from transarterial chemoembolization (TACE). This study aimed to develop a simple validated prognostic score based on the predictive factors for survival in patients with intermediate-stage HCC treated with TACE. Methods Three-hundred and fifty patients with intermediate-stage HCC undergoing initial TACE at Chiba University Hospital (training cohort; n = 187) and two affiliated hospitals (validation cohort; n = 163) were included. Following variables were entered into univariate and multivariate Cox regression models to develop a points-based clinical scoring system: gender, age, etiology, pretreatment, Child–Pugh score, aspartate aminotransferase, creatinine, C-reactive protein, alfa-fetoprotein, size of the largest lesion, and number and location of lesions. Results The number of lesions and the Child–Pugh score were identified as independent prognostic factors in the training cohort. The development of a 0–7-point prognostic score, named the Chiba HCC in intermediate-stage prognostic (CHIP) score, was based on the sum of three subscale scores (Child–Pugh score = 0, 1, 2, or 3, respectively, number of lesions = 0, 2, or 3, respectively, HCV-RNA positivity = 0 or 1, respectively). The generated scores were then differentiated into five groups (0–2 points, 3 points, 4 points, 5 points, and 6–7 points) by the median survival time (65.2, 29.2, 24.3, 13.1, and 8.4 months, respectively; p < 0.0001). These results were confirmed in the external validation cohort (p < 0.0001). Conclusions The CHIP score is easy-to-use and may assist in finding an appropriate treatment strategy for intermediate-stage HCC.

A randomized placebo-controlled trial of prophylactic dexamethasone for transcatheter arterial chemoembolization

This randomized, double‐blind, placebo‐controlled trial evaluated dexamethasone efficacy at preventing fever, anorexia, and nausea/vomiting, the most frequent adverse events of transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). Child‐Pugh class A/B patients with HCC and no macrovascular invasion/extrahepatic metastases were randomly assigned to either a dexamethasone regimen (day 1, intravenous dexamethasone [20 mg] and granisetron [3 mg] before TACE; days 2 and 3, intravenous dexamethasone [8 mg]) or a control regimen (day 1, intravenous placebo [saline] and granisetron [3 mg]; days 2 and 3, intravenous placebo). The primary endpoint was complete response, defined as the absence of grade ≥1 fever, anorexia, or nausea/vomiting according to the Common Terminology Criteria for Adverse Events (version 4.0) and no use of rescue therapy for 120 hours after TACE. A total of 120 patients between October 2010 and June 2013 were randomly assigned to treatment groups. Overall the complete response rate was greater with the dexamethasone regimen than with the control regimen (47.5%, 95% confidence interval 34.3%‐60.9%, versus 10.2%, 95% confidence interval 3.8%‐20.8%; P < 0.001). Cumulative incidences of fever, anorexia, and nausea/vomiting were higher in the control regimen group compared with the dexamethasone group (P < 0.001, P < 0.001, and P = 0.095, respectively). The dexamethasone regimen was generally well tolerated by HCC patients including those with well‐controlled diabetes mellitus and those with hepatitis B virus infection. Conclusion: The dexamethasone regimen was more effective than the control regimen at preventing TACE‐induced fever, anorexia, and nausea/vomiting in patients with HCC. (Hepatology 2018;67:575‐585).

Fatal Diaphragmatic Hernia following Radiofrequency Ablation for Hepatocellular Carcinoma: A Case Report and Literature Review.

An 81-year-old man was admitted to our hospital because of right quadrant abdominal pain. On admission, his liver function was Child-Pugh grade C (10 points). Computed tomography (CT) revealed a diaphragmatic herniation of bowel loops into the right thoracic cavity, accompanied by pleural effusion. Although diaphragmatic hernia was successfully repaired by emergency surgery, he died of liver failure 23 days after the surgery. A retrospective reading of CT images revealed the presence of diaphragmatic injury after radiofrequency ablation (RFA) which had been conducted 33 months before the development of diaphragmatic hernia. Of importance, the lesion of the diaphragmatic injury was located on the estimated needle track of RFA for hepatocellular carcinomas in segment 5 and segment 5/8, but not adjacent to their ablation areas. Subsequently, diaphragmatic perforation had been observed 24 months before admission. This suggests that diaphragmatic hernia caused by RFA is not necessarily due to thermal damage of ablation and is possibly life-threatening, at least in some patients with an impaired liver function.

Successful Interventional Treatment for Arterioportal Fistula Caused by Radiofrequency Ablation for Hepatocellular Carcinoma

Radiofrequency ablation (RFA) is commonly used as a treatment for small hepatocellular carcinoma (HCC). Although several complications such as intraperitoneal bleeding are often observed after RFA, hepatic arterioportal fistula (APF) is a less frequently occurring complication. In this study, we describe two cases of APF caused by RFA, which was successfully occluded by an interventional approach. Case 1 involved a 68-year-old man with solitary HCC in segment VIII of the liver. Both contrast-enhanced computed tomography and color Doppler sonography indicated an APF between the anterosuperior branch of the right hepatic artery (A8) and the portal branch (P8). Concordant with these findings, digital subtraction angiography (DSA) revealed an APF in segment VIII of the liver. Subsequently, the APF was successfully occluded by transarterial embolization (TAE) using gelatin sponge particles. Case 2 involved a 67-year-old man with solitary HCC in segment VII of the liver. Although he developed obstructive jaundice because of hemobilia after RFA, it was improved by endoscopic nasobiliary drainage and the systemic administration of antibiotics. In addition, color Doppler sonography revealed a disturbed flow of the right branch of the portal vein. Similar to case 1, DSA showed an APF between A8 and P8. The APF was successfully embolized by TAE using microcoils. In conclusion, it appears that the formation of APF should be checked after RFA. It is preferable to treat RFA-induced APF promptly by an interventional approach to avoid secondary complications such as portal hypertension and liver dysfunction.

Transcatheter arterial infusion for advanced hepatocellular carcinoma: Who are candidates?

AIM To elucidate anticancer effects of transcatheter arterial infusion chemotherapy (TAI) in patients with hepatocellular carcinoma (HCC). METHODS Data from a total of 95 patients with HCC who received TAI were analyzed retrospectively. The efficacy of TAI was evaluated according to the Response Evaluation Criteria in Cancer of the Liver. Overall survival was calculated from the date of initial treatment to the date of death or last follow-up. Survival curves were calculated by the Kaplan-Meier method, and differences in survival were evaluated by the log rank test. Clinical variables that were identified as statistically different by a univariate analysis were included into the Cox proportional hazard regression model for multivariate analysis. A prognostic index based on the regression coefficients derived from variables identified by the multivariate analysis was constructed. Stratification of the patients was conducted using this prognostic index. RESULTS The patient group was comprised of 76 men and 19 women with an average age of 68 years (range: 37-82 years). Six patients (6.3%) showed complete response and 18 patients (18.9%) showed partial response, for an overall response rate of 25.2%. The median overall survival was 27.6 mo, and the proportions of survivors at 1, 2, and 5 years were 67.4%, 54.0%, and 17.4%, respectively. Multivariate analysis demonstrated that no prior transcatheter arterial chemoembolization, lactate dehydrogenase < 230 IU/L, and performance status of 0 were the independent favorable prognostic factors. The development of a 0-3-point prognostic score index was based on the sum of these three prognostic factors. Subsequently, the patients were categorized into three groups: those with a good (prognostic index = 0-1; n = 54), intermediate (prognostic index = 2; n = 26), or poor (prognostic index = 3; n = 15) prognosis. The median survival times in these three groups were 41.0, 21.2, and 6.8 mo, respectively (P < 0.01). CONCLUSION Our simple prognostic index may be helpful for management of patients in determining treatment strategies for advanced HCC in the era of molecularly targeted therapy.