Kazuto Fukuda

Gd-EOB-DTPA-enhanced magnetic resonance images of hepatocellular carcinoma: correlation with histological grading and portal blood flow

Objective:To retrospectively investigate enhancement patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) in the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced MRI in relation to histological grading and portal blood flow.Methods:Sixty-nine consecutive patients with 83 histologically proven HCCs and DNs were studied. To assess Gd-EOB-DTPA uptake, we calculated the EOB enhancement ratio, which is the ratio of the relative intensity of tumorous lesion to surrounding nontumorous area on hepatobiliary phase images (post-contrast EOB ratio) to that on unenhanced images (pre-contrast EOB ratio). Portal blood flow was evaluated by CT during arterial portography.Results:Post-contrast EOB ratios significantly decreased as the degree of differentiation declined in DNs (1.00 ± 0.14) and well, moderately and poorly differentiated HCCs (0.79 ± 0.19, 0.60 ± 0.27, 0.49 ± 0.10 respectively). Gd-EOB-DTPA uptake, assessed by EOB enhancement ratios, deceased slightly in DNs and still more in HCCs, while there was no statistical difference in the decrease between different histological grades of HCC. Reductions in portal blood flow were observed less frequently than decreases in Gd-EOB-DTPA uptake in DNs and well-differentiated HCCs.Conclusions:Reduced Gd-EOB-DTPA uptake might be an early event of hepatocarcinogenesis, preceding portal blood flow reduction. The hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI may help estimate histological grading, although difficulties exist in differentiating HCCs from DNs.

Reduced risk of hepatocellular carcinoma after interferon therapy in aged patients with chronic hepatitis C is limited to sustained virological responders.

Summary.  This study was undertaken to investigate the effect of interferon (IFN) monotherapy on the risk of hepatocellular carcinoma (HCC) in aged‐patients with chronic hepatitis C. Seven hundred and twenty‐five patients with histologically proven chronic hepatitis C were enrolled in this retrospective cohort study; 531 received IFN monotherapy for 6 months between 1992 and 1995, and 157 were collected as a historical control. The effect of IFN therapy on the development of HCC was compared between the patients with chronic hepatitis C under 60 years old (non‐aged group, n = 531) and those 60 and over (aged group, n = 194). A stepwise Cox proportional‐hazards regression analysis in the non‐aged group revealed that IFN therapy (risk ratio 0.52, 95% CI 0.33–0.81, P = 0.004), older age (P = 0.001), and higher histological stage (P < 0.001) were independent factors associated with the development of HCC. In the aged‐group, only higher histological stage (P = 0.002) and male gender (P = 0.011), but not IFN therapy (risk ratio 0.77, 95% CI 0.42–1.40, P = 0.386), were identified as independent risk factors for HCC, although HCC was significantly reduced when sustained virological response (SVR) was obtained (risk ratio 0.23, 95% CI 0.08–0.64, P = 0.005). In conclusion, inhibitory effect of IFN on development of HCC in the patients with chronic hepatitis C aged 60 and over was limited to the patients achieving SVR when treated with 6 months‐IFN monotherapy.

Comparison of enhancement patterns of histologically confirmed hepatocellular carcinoma between gadoxetate- and ferucarbotran-enhanced magnetic resonance imaging

To compare enhancenent patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) between gadoxetate‐ and ferucarbotran‐enhanced MRI.

High Concentration of Glucose Increases Mitogenic Responsiveness to Heparin-Binding Epidermal Growth Factor–like Growth Factor in Rat Vascular Smooth Muscle Cells

The effect of a high extracellular glucose concentration on the mitogenic response of rat vascular smooth muscle cells (SMCs) to heparin-binding epidermal growth factor-like growth factor (HB-EGF) was investigated. The mitogenic effect of HB-EGF was significantly greater in SMCs cultured in high glucose (25 mmol/L) than in cells cultured in low glucose (5.5 mmol/L) or at high osmolarity (5.5 mmol/L glucose plus 19.5 mmol/L mannitol). The mitogenic effect of epidermal growth factor (EGF), which shares the EGF receptor with HB-EGF, was not affected by glucose concentration. The mitogenic effect of HB-EGF was greater when incubated with heparan sulfate (HS) isolated from SMCs cultured in high glucose than with HS from cells cultured in low glucose. HS synthesized by cells in high glucose was of smaller molecular size and less sulfated than HS synthesized by cells in low glucose. The abundance of mRNA encoding HS-N-deacetylase/N-sulfotransferase (HS-NdAc/NST), a regulatory enzyme in the biosynthesis of HS, was decreased by high glucose in a protein kinase C-independent manner. These observations suggest that the enhanced mitogenic response to HB-EGF in SMCs cultured in high glucose may be attributable to changes in cell-associated HS. Downregulation of HS-NdAc/NST gene expression by high glucose may be related to the altered HS biosynthesis.

Regorafenib as Second-Line Systemic Therapy May Change the Treatment Strategy and Management Paradigm for Hepatocellular Carcinoma

At the European Society of Medical Oncology World Congress of Gastrointestinal Cancer held in Barcelona, Spain, on 30th June 2016, positive outcomes were reported by the Study of Regorafenib after Sorafenib in Patients with Hepatocellular Carcinoma (RESORCE) trial, which investigated the efficacy of regorafenib as second-line therapy after sorafenib failure [1]. In this clinical trial, the group who received regorafenib achieved a survival benefit of approximately 2.8 months compared to the placebo group. Overall survival (OS) was 10.6 months in the regorafenib arm compared with 7.8 months in the placebo arm, with a hazard ratio (HR) of 0.62 (95% confidence interval [CI]: 0.50–0.78; p<0.001). These are groundbreaking results. The positive outcome achieved by this second-line systemic therapy is a major development, especially after the numerous reports of failures in clinical studies of first-and second-line systemic therapeutic agents (table ​(table1).1). Regorafenib therapy is expected to significantly prolong life expectancy by approximately 2.8 months in patients with hepatocellular carcinoma (HCC) who develop progressive disease (PD) during sorafenib therapy. This development will certainly lead to drastic changes in the treatment strategy and management paradigm for HCC. Table 1 Phase III Clinical Trials of Japanese Participation for HCC Design of the RESORCE Trial The RESORCE trial enrolled 573 patients with advanced HCC corresponding to Barcelona Clinic Liver Cancer (BCLC) stage B or C who were unresponsive to sorafenib. The patients were divided into placebo and regorafenib arms at a 1:2 ratio for the daily administration of placebo and oral regorafenib (160 mg), respectively, for three weeks on and one week off (four weeks/cycle) (fig. ​(fig.1).1). Geographic region, performance status on the Eastern Cooperative Oncology Group scale, α-fetoprotein level (≥400 or <400 ng/mL), macrovascular invasion, and extrahepatic disease were used as allocation factors. This study excluded patients who were intolerant of sorafenib and who discontinued the treatment because of side effects. It enrolled only those patients who discontinued sorafenib because of evidence of PD on imaging studies. In addition, patients were included only if they had received ≥400 mg sorafenib for at least 20 of 28 days immediately prior to radiologically detected PD. In other words, this trial was designed (1) to ensure regorafenib tolerance among patients, and to reduce the occurrence of the drug-specific skin symptoms because the compound is structurally similar to sorafenib [2,3] (fig. ​(fig.2)2) and (2) to reduce the effect of post-trial treatment on OS in both the placebo and treatment arms by using a homogeneous group of patients who developed PD due to sorafenib failure. Fig. 1 Design of the RESORCE Trial. ECOG PS=Eastern Cooperative Oncology Group Performance Status; RECIST=Response Evaluation Criteria in Solid Tumors. Fig. 2 Chemical structure of Regorafenib is very similar to that of Sorafenib. In general, post-progression survival (PPS) is defined as the time interval between the diagnosis of PD after primary treatment and the patients death, and OS is the sum of PPS and progression-free survival (PFS). Therefore, even significant differences in PFS can be canceled out because PPS is prolonged. Indeed, OS showed a stronger correlation with PPS than with PFS in a clinical trial of sorafenib [4]. Because HCC responds extremely well to locoregional therapy, it is often used as post-trial treatment even in cases in which locoregional therapy is no longer applicable and molecular targeted agents are subsequently administered in accordance with the protocol, provided that the patients general condition is stable. This rarely happens with other types of cancer and is therefore essentially unique to HCC, owing to the availability of powerful locoregional therapies such as intra-arterial infusion chemotherapy [5, 6, 7], transcatheter arterial chemoembolization (TACE) [8, 9], and radiofrequency ablation [10, 11, 12]. These post-trial treatments are capable of canceling out any difference in the primary endpoint OS by prolonging PPS [13]. Indeed, previous clinical trials of second-line agents other than regorafenib have always included patients intolerant to sorafenib, which may have increased the influence of post-trial treatment and thus contributed to their negative outcomes. Patients unresponsive to sorafenib are those who develop PD during sorafenib therapy and are likely to have relatively poor hepatic function and overall general condition. By contrast, patients intolerant to sorafenib are those who discontinue the treatment because of side effects; these patients are in relatively stable conditions because of negligible amounts of internalized sorafenib, and a lack of HCC progression. Because of their clinical stability, patients intolerant to sorafenib are inevitably treated by locoregional therapy or various other post-trial treatments, including the re-administration of sorafenib, regardless of whether they received an actual second-line agent or placebo during the trial. With this in mind, clinical trials of second-line agents should enroll only patients who are unresponsive to sorafenib [14]. The RESORCE trial was the first clinical study to reflect this point in the trial design (fig. ​(fig.1).1). The benefit of excluding patients intolerant to sorafenib was demonstrated in the subanalysis of a previous phase II study of axitinib, which generated an excellent HR and a significant study outcome [15, 16]. The second noteworthy point in the design of the RESORCE trial is that the allocation factors of macrovascular invasion and extrahepatic disease were treated as independent stratification factors. In general, the designs of previous clinical trials of molecular targeted agents involved allocation factors specifying “vascular invasion and/or extrahepatic spread” or “neither.” However, because vascular invasion is an extremely poor prognostic factor for HCC, assigning vascular invasion to the same category as extrahepatic spread may have influenced the outcome of these clinical trials. For example, when the treatment group contains more patients with vascular invasion but the placebo group includes more patients with extrahepatic spread, such sampling bias will put the treatment group at a significant disadvantage. In fact, such allocation imbalance apparently contributed to a negative outcome in a clinical trial of brivanib as second-line therapy [17] (table ​(table22). Table 2 Imbalance between Brivanib and Placebo Arm in BRISK-PS Trial The design of the RESORCE trial is excellent because it reflects what was learned from the negative outcomes of past trials and the reasons for those outcomes.

Usefulness of the Multimodality Fusion Imaging for the Diagnosis and Treatment of Hepatocellular Carcinoma

A multimodality fusion imaging system has been introduced for the clinical practice of diagnosis and treatment of hepatocellular carcinoma (HCC), especially for loco-regional treatment. An ultrasonography (US) fusion imaging system can provide a side-by-side display of real-time US images and any cross-sectional images of multiplanar reconstruction of CT or MRI that synchronize real-time US. The US fusion imaging system enables us to perform radiofrequency ablation (RFA) for HCCs difficult to detect on conventional US safely. Besides, we can evaluate the treatment effects of RFA easily at the bedside by combining the contrast-enhanced US and the US fusion imaging system. Fusion images of pre- and post-RFA CT have been utilized for the assessment of the treatment effects of RFA. Although the treatment effects of RFA have been conventionally evaluated, comparing pre- and post-RFA CT side-by-side, the evaluation tends to be inaccurate. On CT fusion images, the tumor and the ablation zone are overlaid and we can grasp the positional relation easily, leading to quantitative and more accurate evaluation. The multimodality fusion imaging system has become quite an important tool for loco-regional treatment of HCC because of its usefulness for both the guidance during the RFA procedure and the evaluation of its treatment effects.

Increased Mitogenic Response to Heparin-Binding Epidermal Growth Factor–like Growth Factor in Vascular Smooth Muscle Cells of Diabetic Rats

We investigated the mitogenic effects of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in vascular smooth muscle cells (SMCs) obtained from rats with streptozotocin (STZ)-induced diabetes and evaluated the role of heparan sulfate proteoglycan (HSPG) in inducing these effects. HB-EGF significantly increased DNA synthesis in the SMCs of diabetic rats (STZ-SMCs) compared with control rats (control SMCs). However, the mitogenic effects of EGF, which shares EGF receptors with HB-EGF, and basic fibroblast growth factor, another heparin-binding growth factor, were similar in STZ-SMCs and control SMCs. The mitogenic response to HB-EGF in SMCs of insulin-treated diabetic rats was similar to the response in control SMCs. HB-EGF-induced autophosphorylation of EGF receptors was increased in STZ-SMCs compared with control SMCs, although the number of EGF receptors in STZ-SMCs was 40% of that in controls. This increased mitogenic response to HB-EGF in STZ-SMCs was completely inhibited by treatment with heparitinase, chlorate, and a synthetic peptide corresponding to the heparin-binding domain of HB-EGF. Compared with heparan sulfate isolated from control SMCs, heparan sulfate isolated from STZ-SMCs was of smaller molecular size and caused a greater mitogenic effect of HB-EGF. These findings suggest that the mitogenic response to HB-EGF is increased in SMCs of diabetic rats. Changes in cell-associated heparan sulfate in STZ-SMCs may be related to the increased mitogenic response to HB-EGF.

Ultrasonography fusion imaging system increases the chance of radiofrequency ablation for hepatocellular carcinoma with poor conspicuity on conventional ultrasonography.

Objectives: To investigate the usefulness of the ultrasonography (US) fusion imaging system for radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Methods: Since the US fusion imaging system became available in 2010, we have conducted RFA with this system in all cases. The characteristics of 75 patients with 120 HCCs and 89 patients with 123 HCCs who underwent RFA before the introduction of this system (period A) and after it (period B), respectively, were retrospectively compared. Results: Significant difference in the characteristics of the patients and HCCs between the two periods was found only in the proportion of HCCs with poor conspicuity on grayscale US treated with RFA (1.7%, 2/120 for period A vs. 15.4%, 19/123 for period B, p < 0.01). Among the 19 HCCs with poor conspicuity on grayscale US for period B, 5 and 9 HCCs were identified on grayscale US and contrast-enhanced US, respectively, by the use of the US fusion imaging system, whereas the 5 remaining undetectable HCCs were treated by using the system in conjunction with reference images displayed side-by-side with grayscale US. Conclusion: Since the introduction of the US fusion imaging system, it has become possible to perform RFA for HCCs with poor conspicuity on grayscale US.

Modulation of cholesterol 7α-hydroxylase activity by nonspecific lipid transfer protein in human liver — possibly altered regulation of its cytosolic level in patients with gallstones

Nonspecific lipid transfer protein (nsLTP) partially purified from human liver stimulated human microsomal cholesterol 7 alpha-hydroxylase activity. Addition of the nsLTP preparation to the reaction mixture enhanced the activity two-fold. Treatment of the nsLTP preparation with anti-rat nsLTP antiserum, which cross-reacts with human nsLTP, reduced the 7 alpha-hydroxylase-stimulating ability. These observations suggested that nsLTP plays a role in regulating the 7 alpha-hydroxylase activity in the human liver. 7 alpha-Hydroxylase activity in eight patients with cholesterol gallstones (4.7 +/- 1.6 pmol/min per mg microsomal protein) was significantly lower than that in five controls (7.9 +/- 3.4) (P less than 0.05). The amount of nsLTP in the cytosolic fraction (105,000 X g supernatant) of human liver was determined by dot-blotting immunoquantitation with the antiserum. The cytosolic level of nsLTP in the liver of the patients (716 +/- 239 cpm/3 micrograms protein) was higher than that in the controls (438 +/- 184) although the difference between the two groups was not statistically significant. This suggested that control of the cytosolic level may be affected in patients with cholesterol gallstones.

Hypervascular hepatocellular carcinoma : Combined dynamic MDCT and SPIO-enhanced MRI versus combined CTHA and CTAP

Aim:  Recently, many diagnostic modalities have been developed for the detection of hepatocellular carcinoma (HCC). Of these, a less invasive and more accurate diagnostic procedure is desirable. This study was undertaken to compare combined dynamic multidetector row helical computerized tomography (MDCT) and superparamagnetic iron oxide (SPIO)‐enhanced magnetic resonance imaging (MRI) with combined CT hepatic arteriography (CTHA) and CT during arterial portography (CTAP) for the detection of hypervascular HCC.