Effect of Transcatheter Hepatic Arterial Embolization on Angiogenesis in an Animal Model

Combination of Doxorubicin and Antiangiogenic Agents in Drug-Eluting Beads: In Vitro Loading and Release Dynamics in View of a Novel Therapeutic Approach for Hepatocellular Carcinoma

PURPOSE

Antiangiogenic agents have been used for many years as a first-line systemic treatment for advanced HCC. Embolization with cytostatic drugs on the other hand is the first-line treatment for intermediate HCC. The two types of drugs have not been combined for intraarterial delivery yet. The loading and release dynamics and the in vitro effect of their combination are tested in this experimental study.

MATERIALS AND METHODS

Drug-eluting beads were loaded with doxorubicin, sunitinib and sunitinib analogue piperazine (SAP) alone and with their combinations. Diameter change, loading, release, and effect in cellular proliferation were assessed.

RESULTS

The average microsphere diameter after loading was 473.7 µm (μm) for Doxorubicin, 388.4 μm for Sunitinib, 515.5 μm for SAP, 414.8 μm for the combination Doxorubicin/Sunitinib and 468.8 μm for the combination Doxorubicin /SAP. Drug release in 0.9% NaCl was 10% for Doxorubicin, 49% for Sunitinib, 25% for SAP, 20%/18% for the combination Doxorubicin/Sunitinib, and 18%/23% for the combination Doxorubicin/SAP whereas in human plasma it was 56%, 27%, 13%, 76%/63% and 62%/15%, respectively. The mean concentration of Doxorubicin that led to inhibition of 50% of cellular proliferation in an HCC Huh7 cell line was 163.1 nM (nM), for Sunitinib 10.3 micromolar (μΜ), for SAP 16.7 μΜ, for Doxorubicin/Sunitinib 222.4 nM and for Doxorubicin/SAP 275 nM.

CONCLUSIONS

Doxorubicin may be combined with antiangiogenic drugs with satisfactory in vitro loading and release outcomes and effect on cellular lines.

Tirapazamine-loaded CalliSpheres microspheres: Preparation and characterization as a chemoembolization agent for liver cancer

Tirapazamine (TPZ), a hypoxia-selective cytotoxic agent, has proved to exert synergistic tumor-killing activity with transcatheter arterial embolization (TAE) against liver cancer. This advances TPZ to transcatheter therapies for liver cancer, particularly in combination with drug-eluting microspheres. We describe methods for preparing and characterizing TPZ-loaded CalliSpheres microspheres (CSMTPZs) with regard to their properties as a chemoembolization agent, which includes 1) preparation of CSMTPZs and determination of drug loading level, 2) in vitro determination of TPZ release, 3) assessment of CSMTPZ size and appearance, and 4) determination of TPZ pharmacokinetics and intratumoral drug concentration in vivo. These methods can be adapted for further clinical I trial.•This is to our knowledge the first methods for preparing and characterizing tirapazamine-loaded microspheres with regard to their properties as a chemoembolization agent•Detailed protocols for preparation of CSMTPZs, determination of drug loading level, in vitro determination of TPZ release, assessment of CSMTPZ size and appearance, and in vivo determination of TPZ pharmacokinetics and intratumoral drug concentration•Adaptable to experiments on other animal models and clinical trials.

Tirapazamine-loaded CalliSpheres microspheres enhance synergy between tirapazamine and embolization against liver cancer in an animal model

Tirapazamine (TPZ) is a promising hypoxia-selective cytotoxic agent that may exert synergistic tumor-killing activity with transcatheter arterial embolization (TAE) for liver cancer. To investigated whether TPZ-loaded microspheres enhance the synergy between TPZ and TAE in liver cancer, we prepared TPZ-loaded CalliSpheres microspheres (CSMTPZs) and characterized their properties as a chemoembolization agent in vitro. Tumor hypoxia after TAE was detected in the rabbit VX2 model of liver cancer using a modified Clark-type microelectrode research system. CSMTPZ therapy was performed in the animal model. The plasma and tumor concentrations of TPZ and its metabolites were measured, and the efficacy and safety of CSMTPZ therapy were evaluated and compared with those of the conventional combination of intraarterial TPZ injection and embolization. The results showed that CSMTPZs displayed favorable in vitro properties including drug loading and release and microsphere size, shape, and surface profiles. TAE induced acute tumor hypoxia, but residual tumor cells responded to hypoxia through hypoxia-inducible factor 1α. CSMTPZ therapy improved TPZ delivery into tumor tissue with minimal systemic exposure. Accordingly, CSMTPZ therapy exhibited advantages in terms of hypoxia-selected cytotoxicity, tumor apoptosis and necrosis, animal survival, and safety over the conventional combination of TPZ and TAE. We revealed the improved synergistic anti-tumor effects of CSMTPZ therapy in the rabbit VX2 liver cancer model. Our data support the clinical evaluation of CSMTPZs in the treatment of hepatocellular carcinoma, and CSMTPZ administration might serve as a successful therapeutic strategy for this malignancy.

Adjuvant chemotherapy improves oncological outcomes of resectable intrahepatic cholangiocarcinoma: A meta-analysis

OBJECTIVE

To define the role of adjuvant chemotherapy in the management of resectable intrahepatic cholangiocarcinoma (ICC) by performing a meta-analysis.

SUMMARY BACKGROUND DATA

Oncological benefit of adjuvant chemotherapy in resectable ICC remains controversial, high-level evidence in such context is lacking.

METHOD

A comprehensive search using Pubmed, EMbase, and Web of Science was performed from inception to October 2018. Studies compared the survival of patients receiving adjuvant chemotherapy versus surgery alone were included. Data were analyzed using random effect model. Quality of each study and presence of publication bias were assessed by Newcastle-Ottawa score (NOS) and funnel plot with Egger test respectively.

RESULTS

The present meta-analysis included 15 studies (all were retrospective series) and 5060 patients. Adjuvant chemotherapy was administered either intravenously or intra-arterially in the form of trans-arterial chemo-embolization (TACE). The average NOS for the included studies was 6.5. Pooled analysis of the included studies demonstrated significant advantage in the adjuvant chemotherapy group (HR 0.66, 0.55-079, P <.001, I-square [I] = 20.8%). After 2 studies were removed for heterogeneity, advantage of adjuvant chemotherapy remained (HR 0.72, 0.62-0.84, P <.001, I = 0%). Funnel plot suggested no significant publication bias (Egger test, 2-tailed P = .203). Subgroup analyses suggested that intravenous route of chemotherapy injection (P <.001) and use of gemcitabine base regimen (P = .004) are associated with improved overall survival. Adjuvant chemotherapy did not improve disease-free survival in subgroup analysis (P = .94).

CONCLUSION

Adjuvant chemotherapy is associated with improved overall survival and should be considered in patients with ICC following curative resection and in particular to patients with advance disease.

Zoledronic acid inhibits infiltration of tumor-associated macrophages and angiogenesis following transcatheter arterial chemoembolization in rat hepatocellular carcinoma models

Hepatic transcatheter arterial chemoembolization (TACE), a minimally invasive procedure to block the blood supply of tumors and release of cytotoxic agents, is preferentially applied to patients with hepatocellular carcinoma (HCC) who are not able to receive radical treatments. However, the long-term effects of TACE are unsatisfactory, as the microenvironment following procedure stimulates tumor angiogenesis, which promotes recurrence and metastasis of residual tumors. Tumor associated macrophages (TAMs) have been revealed to stimulate tumor growth and angiogenesis associated with poor prognosis in HCC. The present study focused on the changes in TAMs following TACE, and explored the effects of TACE in combination with the TAM inhibitor zoledronic acid (ZA) in rat HCC models. Orthotropic HCC rats were divided into three groups: Sham TACE, TACE alone and TACE combined with ZA treatment. At 7 or 14 days following TACE, tumor growth was evaluated by magnetic resonance imaging (MRI). Infiltration of TAMs was assessed by histological analysis and flow cytometry. Tumor angiogenesis was measured as the mean vessel density, and initial slope was calculated from dynamic contrast enhancement MRI. Local and systemic levels of vascular endothelial growth factor (VEGF) were determined by western blotting or an ELISA, respectively. The results revealed that TACE inhibited tumor growth at 7 days following the procedure, but this inhibition was attenuated at 14 days following the procedure compared with the sham TACE control. If combined with ZA treatment, TACE exhibited a stable inhibition effect on tumor growth until the end of observation. Investigation of the underlying mechanisms demonstrated that TACE combined with ZA treatment inhibited infiltration of F4/80 positive TAMs and tumor angiogenesis compared with the TACE alone group at 14 days following the procedure. Additionally, the combination treatment significantly inhibited secretion of VEGF in the present models. In conclusion, ZA treatment enhanced the effects of TACE through inhibiting TAM infiltration and tumor angiogenesis in rat HCC models.

The Clinical Impact of Transcatheter Arterial Chemoembolization (TACE)-Induced c-Met Upregulation on TACE Refractoriness in Hepatocellular Carcinoma

BACKGROUND

Transcatheter arterial chemoembolization (TACE) is a widely used and well-established treatment for hepatocellular carcinoma (HCC). However, TACE loses its therapeutic efficacy when performed repeatedly, a phenomenon termed TACE refractoriness. c-Met is associated with malignant potential and with resistance to anti-tumor therapies in some kinds of cancers.

AIMS

The aim of this study is to investigate the clinical impact of TACE on c-Met expression with the aim of understanding the mechanism underlying TACE refractoriness.

METHODS

The effect of TACE on the c-Met expression level was investigated in vitro in HCC cell lines, and it was shown that c-Met expression is upregulated in HCC cell lines cultured under hypoxia and/or exposed to chemotherapeutic agents. The in vitro results were validated using 82 clinical samples of HCC with and without preoperative TACE treatment.

RESULTS

c-Met upregulation was observed significantly more frequently in clinical samples of HCC that were treated with preoperative TACE than in samples with no TACE treatment. Increased c-Met expression was significantly associated with poor prognosis. Furthermore, the incidence of c-Met-positive expression was significantly higher in TACE-refractory HCC samples.

CONCLUSIONS

TACE treatment upregulates c-Met expression in HCC and the upregulated c-Met expression may be responsible for TACE refractoriness.

Combining dynamic contrast enhanced magnetic resonance imaging and microvessel density to assess the angiogenesis after PEI in a rabbit VX2 liver tumor model

OBJECTIVES

To evaluate the correlation between parameters of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and microvessel density (MVD) measurements in rabbit VX2 liver tumor models after percutaneous ethanol injection (PEI) and to observe influence of PEI on angiogenesis in a rabbit VX2 liver tumor model with dynamic contrast enhanced magnetic resonance imaging (DCE-MRI).

MATERIALS AND METHODS

Forty five New Zealand white rabbits were used in this study. VX2 tumor tissue blocks were implanted in the left lobe of liver by percutaneous puncture under CT guidance. 2 weeks later, all rabbits underwent conventional MRI (T1WI, T2WI) to determine the successful models. Then those successful implanted VX2 liver tumor models in the study were randomly divided into the control group and the experimental group, the former did not have processing, and the latter underwent PEI under CT guidance. MRI (T1WI, T2WI and DCE-MRI) was performed 1 week later again, the parameters of DCE-MRI (Ktrans, Kep, Ve and iAUC60) of viable tumor portions were observed. Then all the liver samples were processed for hematoxylin and eosin (H&E) staining and immunohistochemical staining for CD31 to determine MVD. At last, data (including DCE-MRI perfusion parameters and MVD) were compared between experimental and control groups, correlation of DCE-MRI perfusion parameters and MVD was evaluated.

RESULTS

Twenty six VX2 liver tumor models underwent all examinations (thirteen models for each group) 1 week later after PEI. For the experimental group, the parameters Ktrans (r=0.6382, P=0.0189) and iAUC60 (r=0.6591, P=0.0143) in viable tumor portions were positively moderately correlated with MVD, whereas the parameters Kep (r=0.4656, P=0.1088) and Ve (r=0.2918, P=0.3333) were not correlated with MVD. For the control group, the parameters Ktrans (r=0.6385, P=0.0188) and iAUC60 (r=0.6391, P=0.0187) in viable tumor portions were also positively moderately correlated with MVD, while the parameters Kep (r=0.5518, P=0.0506) and Ve (r=-0.0824, P=0.789) were not correlated with MVD. Ktrans, Kep, Ve, iAUC60 and MVD of residual viable tumors in the experimental group 1 week later after PEI were similar to the viable tumors of the control group (P>0.05).

CONCLUSIONS

DCE-MRI could be used to evaluate the efficiency of VX2 liver tumor after PEI. The quantitative parameter Ktrans and semi-quantitative parameter iAUC60 of DCE-MRI are correlated with MVD, which can assess tumor angiogenesis noninvasively of VX2 liver tumor model, and ethanol has no significant impact on angiogenesis of viable tumor 1week later after PEI.

Treatment of Liver Cancer

Primary liver cancer, mostly hepatocellular carcinoma, remains a difficult-to-treat cancer. Incidence of liver cancer varies geographically and parallels with the geographic prevalence of viral hepatitis. A number of staging systems have been developed, reflecting the heterogeneity of primary liver cancer, regional preferences, and regional variations in resectability or transplant eligibility. Multimodality treatments are available for this heterogeneous malignancy, and there are variations in the management recommendations for liver cancers across specialties and geographic regions. Novel treatment strategies have merged with the advance of new treatment modalities. This work focuses on reviewing the incidence, staging, and treatment of liver cancer.

Immediate and Late Outcomes of Bronchial and Systemic Artery Embolization for Palliative Treatment of Patients With Nonsmall-Cell Lung Cancer Having Hemoptysis

Background:

Hemoptysis in patients with advanced lung cancer can be a life threatening.

Objectives:

To evaluate immediate outcomes and late outcomes of bronchial artery embolization (BAE) for palliative treatment in patients with advanced nonsmall-cell lung cancer (NSCLC) having hemoptysis.

Methods:

The BAE was performed in 28 patients with NSCLC. Hemoptysis was defined as follows: massive bleeding greater than 300 mL within 24 hours (n = 8), moderate bleeding of 100 to 300 mL within 24 hours (n =12), and slight bleeding less than100 mL within 24 hours (n = 8).

Results:

Success rate was 96%. Immediate clinical success within 24 hours after BAE was achieved in 22 of the 27 patients who underwent embolization.

Conclusions:

The BAE with gelatin sponge particles can provide good management of hemoptysis as a palliative treatment in patients with advanced NSCLC.

Staging, prognostic factors and adjuvant therapy of intrahepatic cholangiocarcinoma after curative resection

BACKGROUND & AIMS

Prognostic factors and adjuvant therapy of intrahepatic cholangiocarcinoma (ICC) after curative resection were not clear. We aim to analyse prognostic factors after curative resection and evaluate adjuvant therapy and survival based on the new staging system.

METHODS

A retrospective analysis of 283 patients who underwent surgical exploration for ICC was performed. Staging was performed according to the 7th edition AJCC staging manual. Univariate and multivariate analyses were used to evaluate independent prognostic factors.

RESULTS

The difference for OS at different TNM stages after R0 resection was significant (P < 0.001). Despite regional lymph node metastasis, tumour number and vascular invasion, serum GGT level was also an independent prognostic factor for OS of patients after R0 resection. The incidence of biliary and vascular invasion was significantly higher in high GGT group than in normal GGT group. Factors predictive of recurrence were multiple tumours and regional lymph node metastasis. After R0 resection, adjuvant TACE not only did not improve the OS of patients at TNM stage I (P = 0.508), but significantly promoted recurrence of these patients (P = 0.006). Only patients at TNM stage II, III and IV benefited from adjuvant TACE for longer survival, while the recurrence rates were not affected.

CONCLUSIONS

The new staging system can predict the survival of ICC patients after R0 resection. High GGT level may be suggestive of biliary and vascular invasion and was an independent risk factor for OS after R0 resection. Adjuvant TACE may be indicated only for patients at advanced stages for better survival.

Influence of preoperative transcatheter arterial chemoembolization on gene expression in the HIF-1α pathway in patients with hepatocellular carcinoma

PURPOSE

Although transcatheter arterial chemoembolization (TACE) is the most common treatment option in patients with hepatocellular carcinoma (HCC), its clinical benefits remain still controversial. Since TACE induces hypoxic necrosis in tumors, hypoxia-inducible factor 1α (HIF-1α) could critically affect biology in residual tumors after TACE treatment and subsequent prognosis. However, HIF-1α and its prognostic relevance in TACE have rarely been examined in human specimens. In the current study, we investigated the prognosis and expression of genes regulated by HIF-1α in HCC patients receiving preoperative TACE for the first time.

METHODS

In total, 35 patients with HCC (10 patients undergoing preoperative TACE) were retrospectively studied. The prognostic significance of TACE was analyzed using Kaplan-Meier and Cox regression models. Protein levels of HIF-1α and mRNA levels of HIF-1α-associated genes were examined using immunohistochemistry (IHC) and real-time RT-PCR, respectively.

RESULTS

Preoperative TACE was significantly associated with increased 2-year recurrence rate (80 vs. 36 %, P = 0.00402) and shorter disease-free survival (DFS) time (11.9 vs. 35.7 months, P = 0.0182). TACE was an independent prognostic factor for recurrence (P = 0.007) and poor DFS (P = 0.010) in a multivariate analysis. Immunohistochemical staining revealed in vivo activation of HIF-1α in human specimens treated with TACE. Notably, protein levels of HIF-1α were significantly increased in TACE tissues demonstrated by IHC. Transcriptional targets of HIF-1α showed mRNA expression patterns consistent with activation of HIF-1α in TACE tissues.

CONCLUSIONS

Our findings collectively demonstrate that preoperative TACE confers poor prognosis in HCC patients through activation of HIF-1α.

The efficacy of radiofrequency ablation combined with transcatheter arterial chemoembolization for primary hepatocellular carcinoma in a cohort of 487 patients

Although diagnostic methods, surgical techniques, and perioperative care have undergone significant advancement over the past decades, the prognosis of primary hepatocellular carcinoma (HCC) remains discouraged because of the high postoperative recurrence rate and high cancer mortality. Radiofrequency ablation (RFA) combined with transcatheter arterial chemoembolization (TACE) is a recently developed means for the treatment of HCC. In this study, we analyzed the efficacy of RFA plus TACE in 487 cases of HCC in our institution. We observed that the 1-, 2-, 3-, 4- and 5-year rates of overall survival rates after RFA and TACE treatment were 97.5% (475/487), 89.4% (277/310), 84.2% (181/215), 80.4% (150/186) and 78.7% (141/177), respectively. We did not find that age or tumor location (the caudate group or non-caudate group) plays a role in this cohort. However, we have identified that tumor recurrent status, the number of tumors, albumin (ALB), prothrombin time (PT) and platelet count (PLT) were significantly associated with poor overall survival in HCC patients receiving RFA combined with TACE. Interestingly, tumor size did not significantly impact overall survival, indicating that RFA combined with TACE for HCC treatment has the same efficiency for different sizes of tumors. Our results provide evidence for the rationale for using combined RFA and TACE in the treatment of primary HCC.

Drug-eluting beads loaded with antiangiogenic agents for chemoembolization: in vitro sunitinib loading and release and in vivo pharmacokinetics in an animal model

PURPOSE

The combination of embolic beads with a multitargeted tyrosine kinase inhibitor that inhibits tumor vessel growth is suggested as an alternative and improvement to the current standard doxorubicin-eluting beads for use in transarterial chemoembolization. This study demonstrates the in vitro loading and release kinetics of sunitinib using commercially available embolization microspheres and evaluates the in vitro biologic efficacy on cell cultures and the resulting in vivo pharmacokinetics profiles in an animal model.

MATERIALS AND METHODS

DC Bead microspheres, 70-150 µm and 100-300 µm (Biocompatibles Ltd., Farnham, United Kingdom), were loaded by immersion in sunitinib solution. Drug release was measured in saline in a USP-approved flow-through apparatus and quantified by spectrophotometry. Activity after release was confirmed in cell culture. For pharmacokinetics and in vivo toxicity evaluation, New Zealand white rabbits received sunitinib either by intraarterial injection of 100-300 µm sized beads or per os. Plasma and liver tissue drug concentrations were assessed by liquid chromatography-tandem mass spectroscopy.

RESULTS

Sunitinib loading on beads was close to complete and homogeneous. A total release of 80% in saline was measured, with similar fast-release profiles for both sphere sizes. After embolization, drug plasma levels remained below the therapeutic threshold (< 50 ng/mL), but high concentrations at 6 hours (14.9 µg/g) and 24 hours (3.4 µg/g) were found in the liver tissue.

CONCLUSIONS

DC Bead microspheres of two sizes were efficiently loaded with sunitinib and displayed a fast and almost complete release in saline. High liver drug concentrations and low systemic levels indicated the potential of sunitinib-eluting beads for use in embolization.

Octreotide and celecoxib synergistically encapsulate VX2 hepatic allografts following transcatheter arterial embolisation

To evaluate the encapsulation of VX2 hepatic allografts in rabbits induced by octreotide and celecoxib administration following transcatheter arterial embolisation (TAE), rabbits with hepatic VX2 allografts were divided into four groups: control, TAE, octreotide + celecoxib (O+C) and the multimodality therapy (TAE+O+C). Allograft metastasis, capsule thickness and percentage of clear cells were measured and vascular endothelial growth factor (VEGF) and CD31 were detected by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The extrahepatic metastases of each intervention group were significantly fewer than those of the control group, with the TAE+O+C group exhibiting the fewest extrahepatic metastases. The TAE+O+C group had the greatest proportion of clear cells and thickest capsule on day 30. Increased capsule thickness was negatively correlated with tumour metastasis. In addition, VEGF expression levels assessed by immunohistochemistry and RT-PCR in the three intervention groups were significantly lower than those in the control group. Furthermore, the TAE+O+C group had a significantly reduced CD31 count induced by TAE. These results demonstrate that TAE, followed by long-term administration of octreotide and celecoxib, synergistically inhibits VX2 hepatic allograft metastasis by increasing the proportion of clear cells, promoting encapsulation and inhibiting angiogenesis.

Current status of hepatocellular carcinoma treatment in Japan: transarterial chemoembolization

Transarterial chemoembolization (TACE) is the gold standard of treatment for intermediate-stage hepatocellular carcinoma (HCC), and involves the administration of cytotoxic drugs, with or without lipiodol, by means of a catheter directly to the hepatic artery followed by the administration of embolizing agents such as spherical gelatin or polyvinyl alcohol particles. There are currently no global guidelines regarding the dose, choice or combination of cytotoxic agents for TACE; therefore it is difficult to compare data from different TACE studies. Superselective TACE with lipiodol is the primary TACE procedure that offers satisfactory levels of local control with a lower risk of complications. Approximately 40-70% of patients with HCC with tumours sized 4-5 cm or less attained complete tumour necrosis or remained local recurrence free for 3 years or longer following TACE. The early identification of unresponsiveness to TACE is important to allow for a timely switch to alternative therapies. The use of novel embolizing materials in TACE such as drug-eluting beads and radioembolization is likely to have beneficial effects. Indeed, the increase in angiogenic activity following TACE emphasizes the potential of TACE in combination with targeted molecular therapies such as the anti-angiogenesis inhibitor, sorafenib.

Transcatheter arterial embolization followed by octreotide and celecoxib synergistically prolongs survival of rabbits with hepatic VX2 allografts

OBJECTIVE

To validate the efficacy of an innovative multimodality therapy with transcatheter arterial embolization (TAE) plus octreotide and celecoxib in reducing neoangiogenesis and prolonging the survival of rabbits with hepatocellular carcinoma.

METHODS

Rabbits with hepatic VX2 allografts were divided into four groups: control group, TAE group, octreotide + celecoxib (O + C) group and the multimodality therapy (TAE + O + C) group. Survival of the rabbits was analyzed using the Kaplan-Meier method and the expression of CD31 in tumor tissues was detected by immunohistochemistry.

RESULTS

Rabbits in the TAE + O + C group lived nearly 20 days longer than those in the control group. The survival rate of the TAE + O + C group was 50% at day 80 and was the highest among the four groups (P < 0.05). No VX2 allograft-bearing rabbits in the control group lived longer than 60 days. Compared with the control group, the survival time of the other two intervention groups were not prolonged significantly (P > 0.05). The CD31 expression induced by TAE was reduced significantly in TAE + O + C group (P < 0.05). Less metastasis was detected in TAE + O + C group.

CONCLUSION

TAE followed by the long-term administration of octreotide and celecoxib can synergistically prolong the survival of rabbits with hepatic VX2 allografts by inhibiting potential neoangiogenesis, tumor growth and metastasis.

Embolization therapy for benign prostatic hyperplasia: influence of embolization particle size on gland perfusion

PURPOSE

To assess the influence of embolic size on the therapy response of prostatic arterial embolization (PAE) based on perfusional changes seen on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Twelve beagles underwent PAE, four dogs with each particle size: A: 100-300 μm; B: 300-500 μm; and C: 500-700 μm. Prior to and 1 month after the embolization all dogs underwent prostate DCE MRI.

RESULTS

After embolization, time to maximal perfusion intensity for prostate parenchyma increased in B (188 vs. 135 sec, P = 0.023) and C (200 vs. 120 sec, P = 0.001), while it did not change for A (139 vs. 124 sec, P = 0.39). The maximal relative intensity increased after embolization in C (3.84 vs. 2.38, P < 0.001), while it did not change for A (2.50 vs. 2.44, P = 0.36) and B (3.23 vs. 2.9, P = 0.21). The extent of visualized intraprostatic urethral wall increased after embolization in B compared with A and C, 239.5 ± 138.1% vs. 56.1 ± 34.3, P = 0.04. Enhancement changes correlated with prostate volume changes: prostate volumes in A decreased less as compared with B and C (77 ± 34% vs. 56 ± 14%), P = 0.02.

CONCLUSION

The enhancement and morphological data are useful to monitor response to therapy after embolization. Embolization with 300-500 and 500-700 μm particle may provide better results than with 100-300 μm particles in a canine model.

Contrast-enhanced ultrasound after devascularisation of neuroendocrine liver metastases: functional and morphological evaluation

OBJECTIVE

To evaluate morphological and perfusion changes in liver metastases of neuroendocrine tumours by contrast-enhanced ultrasound (CEUS) after transarterial embolisation with bead block (TAE) or trans-arterial chemoembolisation with doxorubicin-eluting beads (DEB-TACE).

METHODS

In this retrospective study, seven patients underwent TAE, and ten underwent DEB-TACE using beads of the same size. At 1 day before embolisation, 2 days, 1 month and 3 months after the procedure, a destruction-replenishment study using CEUS was performed with a microbubble-enhancing contrast material on a reference tumour. Relative blood flow (rBF) and relative blood volume (rBV) were obtained from the ratio of values obtained in the tumour and in adjacent liver parenchyma. Morphological parameters such as the tumour's major diameter and the viable tumour's major diameter were also measured. A parameter combining functional and morphological data, the tumour vitality index (TVI), was studied. The Wilcoxon rank-sum test and Fisher's test were used to compare treatment groups.

RESULTS

At 3 months rBF, rBV and TVI were significantly lower (P = 0.005, P = 0.04 and P = 0.03) for the group with doxorubicin. No difference in morphological parameters was found throughout the follow-up.

CONCLUSIONS

One parameter, TVI, could evaluate the morphological and functional response to treatments.

Transarterial therapies for hepatocellular carcinoma

Transarterial therapies for hepatocellular carcinoma are considered palliative and should be offered to patients with intermediate stage multinodular disease without extra-hepatic metastases and sufficient liver reserve. They mainly include transarterial chemoembolisation and transarterial embolisation. While transarterial therapy is now a validated treatment for unresectable HCC, there is still a lack of conclusive evidence as to which type and schedule is the optimal procedure. This is mainly due to the lack of standardisation. Combining local therapies or intra-arterial therapies with systemic targeted therapies might prove more effective strategies in the future. In the present article, we review transarterial therapies and critically comment on their indications, complications and outcomes.

Combination therapy of transcatheter arterial chemoembolization and arterial administration of antiangiogenesis on VX2 liver tumor

PURPOSE

This study was designed to evaluate the antitumorigenic efficiency of Endostar (an antiangiogenic agent) arterially administrated combined with transcatheter arterial chemoembolization (TACE) on liver tumor, and validation of perfusion CT for quantitative measurements of the results.

EXPERIMENTAL DESIGN

Thirty rabbits bearing VX2 liver tumors were randomly and equally distributed into three groups. One of the following treatment protocols was performed in each group: 1) group 1 was treated with TACE and simultaneously arterially administrated Endostar; 2) group 2 with TACE alone, and 3) a control group that had saline injected through hepatic artery. Routine CT scan was performed before treatment, and perfusion CT imaging was performed 2 weeks after treatment. Immunohistochemical biomarkers of microvascular density (MVD) and the expression of vascular endothelial growth factor (VEGF) were measured for assessments of angiogenesis.

RESULTS

We observed a statistically significant reduction from the control in the volume, growth rate, and size of the tumor 2 weeks after treatment with both TACE plus Endostar and with TACE alone (P < 0.01). Although there was no statistically significant difference in tumor size between the group with TACE plus Endostar and the group with TACE alone (P > 0.05), MVD and VEGF were significantly less expressed in the TACE plus Endostar group than both groups with TACE alone and the control group (P < 0.01). Blood flow (BF), blood volume (BV), and permeability-surface area products (PS) in the group with TACE plus Endostar on perfusion CT were significantly higher than other two groups (P < 0.05), which were positively correlated with the MVD and VEGF values (P < 0.05).

CONCLUSIONS

TACE with arterial administration of Endostar simultaneously significantly inhibited the angiogenesis biomarkers associated with TACE in a rabbit model bearing VX2 liver tumor, which indicates that the combined treatment protocol may have potential synergistic effects on liver cancer. It also is suggested that perfusion CT may be useful for monitoring antiangiogenic/antivascular treatment in the liver tumors.

Oxidative stress is closely associated with tumor angiogenesis of hepatocellular carcinoma

BACKGROUND

Oxidative stress (OS) plays an important role in the progression of chronic liver disease and hepatocarcinogenesis. However, the role of OS in the progression of hepatocellular carcinoma (HCC) is unclear. The aim of this study was to assess whether OS promotes angiogenesis in HCC.

METHODS

The expressions of vascular endothelial growth factor (VEGF), VEGF receptor2 (VEGFR2), and phosphorylated Akt were assessed, and microvessel density (MVD) and the cancer-associated fibroblast (CAF) population were examined by immunohistological staining in 55 HCC samples. The OS level in these tissues was assessed using 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE) immunostaining, and an 8-OHdG enzyme-linked immunosorbent assay (ELISA). The expression and activation of angiogenic factors and the effect of growth stimulation of human umbilical vein endothelial cells (HUVECs) were also assessed in vitro, using HLE hepatoma-derived cells and conditioned medium with or without treatment with hydrogen peroxide (H₂O₂); a phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin; and an anti-oxidative agent, N-acetyl-L-cysteine (NAC).

RESULTS

A higher OS grade was significantly associated with higher MVD, VEGF expression, Akt activity, and OS grade of CAFs, but not with the percentage of the CAF population in HCC tissues. Additionally, cancer cells constituted a major population of OS marker-positive cells in HCC tissues. In vitro, H₂O₂ treatment induced up-regulation of VEGF at both the mRNA and protein levels, activated Akt, and resulted in the proliferation of HUVECs; the addition of wortmannin and NAC counteracted the effects of OS.

CONCLUSIONS

OS enhances the malignant potential of HCC through the stimulation of angiogenesis by activation of the Akt-VEGF pathway.

Longterm follow-up after transarterial chemotherapy for hepatocellular carcinoma in a Scandinavian centre

BACKGROUND

Transarterial chemotherapy infusion (TAI) with lipiodol is a palliative treatment for hepatocellular carcinoma. The aim of this study was to describe the outcomes of TAI from a single scandinavian centre between 1995 to 2008.

METHODS

The study is a retrospective analyse of prospectively collected data. TAI (doxorubicin, 50 mg with lipiodol) was administrated every 6 weeks. After 5 treatments, a CT scan was performed, and if the disease was stable, (RECIST score) treatment was continued.

RESULTS

57 patients with HCC were treated with TAI. Median age; 72 years (52-84), 41 (71%) men. 52 (91%) had Child-Pugh score A, and 5 (9%) had Child-Pugh B. Nine (16%) patients had a BCLC score A, 19 (33%) B, 29 (51%) C, while none was classified as BCLC D. Twenty nine (51%) patients had a tumour size ≥ 10 cm. In total 254 treatments were performed, a median of 4 (1-20) per patient. Treatment mortality was 0%. In 30 (53%) patients the treatment strategy was not completed due to deteriorating clinical conditions. Median survival was 17 months (2-108), 2, 3, and 5-years survival was 34%, 22%, and 13%, respectively. Patients that responded to treatment (n = 23) had a median survival of 26 (13-108) months compared to 8 (2-48) months for those not fulfilling the treatment plan, p < 0.05. Tumour size ≥ 10 cm, AFP ≥ 400 µg/l, and Child-Pugh class B or C were negative prognostic factors for survival, p < 0.05.

CONCLUSIONS

The 5 year survival was 13%, and median survival 17 months. Treatment mortality was 0%. Patients that responded to treatment (40%) had a median survival of 26 months. TAI provides good palliation but selection of patients is crucial.

Luminescence targeting and imaging using a nanoscale generation 3 dendrimer in an in vivo colorectal metastatic rat model

Surgery is currently the best approach for treating either primary or metastatic hepatic malignancies. Because only 20% of hepatic cancers are operable in patients, several types of regional therapy (RT) are emerging as alternate treatment modalities. However, RTs can have their own limitations at controlling tumor growth or may lack the ability to detect such metastases. Additional strategies can be implemented to enhance their efficacy. An animal model of hepatic metastases coupled with a gastroduodenal artery (GDA) cannulation technique may provide a site to apply such therapies. In our study, splenic injections were performed with CC531 adenocarcinoma cells, which generated metastatic hepatic tumors in WAG/RijHsd rats. Cannulation of GDA was achieved via a polyethylene catheter. Infusion of generation 3 polyamidoamine 4-amino-1,8-naphthalimide dendrimer containing 8 europium ions (Eu-G3P4A18N) via the GDA resulted in luminescence of the hepatic metastatic nodules. Imaging of the metastatic hepatic nodules was obtained with the help of a cooled charge coupled device (CCD) camera.

FROM THE CLINICAL EDITOR

Hepatic malignancies represent a major therapeutic challenge, despite the available surgical and oncologic treatment modalities. In this paper, an animal model of hepatic adenocarcinoma is used in demonstrating successful targeting of spleen metastases with generation 3 polyamidoamine 4-amino-1,8-naphthalimide dendrimer containing 8 europium ions (Eu-G3P4A18N) for luminescence imaging.

Addition of transcatheter arterial chemoembolization decreased local recurrence but had no survival benefit to percutaneous ethanol injection therapy for patients with small hepatocellular carcinoma: A multicenter randomized control study

To assess the efficacy of the additional treatment of transcatheter arterial chemoembolization (TACE) to percutaneous ethanol injection (PEI) therapy for relatively small hepatocellular carcinomas (HCCs), a multicenter randomized control study (RCT) was performed. We conducted an RCT and follow-up study during the enrollment period from 1997 to 1999. Newly diagnosed patients with one to three HCC tumors measuring from 2 to 4 cm (4 cm maximum) in diameter were enrolled. A total of 30 patients initially underwent a combination TACE-PEI or PEI-alone therapies at eight randomly assigned Japanese hospitals. However, 3 patients withdrew. Of the 27 remaining patients, 13 were treated with the combination TACE-PEI therapy and 14 with PEI therapy alone. The patients were observed over several months [median (interquartile range) 33.2 (24.6) months]. There were no significant differences in the background of the patients between the two groups. Among the patients treated with TACE-PEI, the development of a local residual tumor was of significantly lower occurence, compared to the group receiving PEI alone (7.6 and 42.9%, respectively; P=0.024). However, the mean cancer-free time (absence of local or multiple nodule recurrence) or patient survival time was not significantly different between the two groups [PEI alone vs. TACE-PEI: cancer-free time 16.7 (95% CI 7.3-26.0) vs. 22.9 months (95% CI 12.4-33.4); survival time 57.2 (95% CI 37.2-77.2) vs. 42.4 months (95% CI 29.2-55.6)]. Although the combination of TACE and PEI had significant effects on the local tumor control, no efficacy of the addition of TACE to PEI was noted in the prognosis among patients with relatively small HCC tumors.

Experimental evaluation of inhibitory effect of 10-hydroxycamptothecin on hypoxia-inducible factor-1α expression and angiogenesis in liver tumors after transcatheter arterial embolization

PURPOSE

To evaluate the effect of transcatheter administration of 10-hydroxycamptothecin (HCPT), a hypoxia-inducible factor-1α (HIF-1α) inhibitor, on HIF-1α expression and angiogenesis in liver tumors after transcatheter arterial embolization in an animal model.

MATERIALS AND METHODS

VX2 tumors were implanted in the livers of 30 rabbits. The animals were divided randomly into three groups of 10 animals each. Group 1 animals received hepatic intraarterial infusion of distilled water. Group 2 animals received iodized oil infusion followed by embolization with 150-250 μm of polyvinyl alcohol particles. Group 3 animals received infusion of a mixture of HCPT (1 mg/kg body weight) with iodized oil followed by the particle embolization. Six hours or 3 days after transcatheter treatment, the animals were sacrificed, and the tumor samples were harvested. Immunohistochemical staining was performed to evaluate the levels of HIF-1α and vascular endothelial growth factor (VEGF) protein as well as microvessel density.

RESULTS

The levels of HIF-1α and VEGF and microvessel density in tumors of group 2 were significantly higher than those of group 1 or 3 (P < .05). However, no significant differences were noted in tumors between group 1 and 3 (P > .05). HIF-1α levels were significantly correlated with VEGF levels (r = .587, P = .001) and microvessel density (r = .527, P = .003).

CONCLUSIONS

Transcatheter infusion of HCPT has an inhibitory effect on HIF-1α expression and angiogenesis in liver tumors after transcatheter arterial embolization.

Nonoperative therapies for combined modality treatment of hepatocellular cancer: expert consensus statement

Although surgical resection and liver transplantation are the only treatment modalities that enable prolonged survival in patients with hepatocellular carcinoma (HCC), the majority of HCC patients presents with advanced disease and do not undergo resective or ablative therapy. Transarterial chemoembolization (TACE) is indicated in intermediate/advanced stage unresectable HCC even in the setting of portal vein involvement (excluding main portal vein). Sorafenib has been shown to improve survival of patients with advanced HCC in two controlled randomized trials. Yttrium 90 is a safe microembolization treatment that can be used as an alternative to TACE in patients with advanced liver only disease or in case of portal vein thrombosis. External beam radiation can be helpful to provide local control in selected unresectable HCC. These different treatment modalities may be combined in the treatment strategy of HCC and also used as a bridge to resection or liver transplantation. Patients should undergo formal multidisciplinary evaluation prior to initiating any such treatment in order to individualize the best available options.

Expression of hypoxia-inducible factor-1alpha in liver tumors after transcatheter arterial embolization in an animal model

To examine the effect of transcatheter arterial embolization (TAE) of liver tumors on hypoxia-inducible factor-1alpha (HIF-1alpha) expression in the residual viable tumor, a total of 30 New Zealand White rabbits implanted with VX2 liver tumor were divided into 2 groups. TAE-treated group animals (n=15) were subjected to TAE with 150-250 microm polyvinyl alcohol particles. Control group animals (n=15) underwent sham embolization with distilled water. Six hours, 3 days or 7 days after TAE, the animals were sacrificed, and samples of tumor and adjacent normal liver tissue were harvested. Expression of HIF-1alpha protein was examined immunohistochemically. Real-time PCR was performed to examine the HIF-1alpha mRNA levels. Our results showed that HIF-1alpha protein was expressed in the VX2 tumors but not in the adjacent normal liver tissue. The HIF-1alpha-positive tumor cells were located predominantly at the periphery of necrotic tumor regions. The mean levels of HIF-1alpha protein were significantly higher in TAE-treated tumors than those in control tumors (P=0.002). Among the three sacrificing time points, the difference in increase in HIF-1alpha protein was significant between the two groups at the sacrificing time point of 6 h and 3 days after TAE (P=0.020, P=0.031, respectively), whereas no significant increase was noted 7 days after TAE (P=0.502). In contrast, although HIF-1alpha mRNA was expressed in TAE-treated and control VX2 tumors, there existed no significant difference in the HIF-1alpha mRNA level between the two groups (P=0.372). It is concluded that TAE of liver tumors increases the expression of HIF-1alpha at protein level in the residual viable tumor, which could be attributed to hypoxia generated by the procedure.

Correlation of hypoxia-inducible factor 1alpha with angiogenesis in liver tumors after transcatheter arterial embolization in an animal model

This study sought to determine the expression of hypoxia-inducible factor 1alpha (HIF-1alpha) and its relation to angiogenesis in liver tumors after transcatheter arterial embolization (TAE) in an animal model. A total of 20 New Zealand White rabbits were implanted with VX2 tumor in liver. TAE-treated group animals (n = 10) received TAE with polyvinyl alcohol particles. Control group animals (n = 10) received sham embolization with distilled water. Six hours or 3 days after TAE, animals were humanely killed, and tumor samples were collected. Immunohistochemical staining was performed to evaluate HIF-1alpha and vascular endothelial growth factor (VEGF) protein expression and microvessel density (MVD). Real-time polymerase chain reaction was performed to examine VEGF mRNA levels. The levels of HIF-1alpha protein were significantly higher in TAE-treated tumors than those in the control tumors (P = 0.001). HIF-1alpha protein was expressed in viable tumor cells that were located predominantly at the periphery of necrotic tumor regions. The levels of VEGF protein and mRNA, and mean MVD were significantly increased in TAE-treated tumors compared with the control tumors (P = 0.001, 0.000, and 0.001, respectively). HIF-1alpha protein level was significantly correlated with VEGF mRNA (r = 0.612, P = 0.004) and protein (r = 0.554, P = 0.011), and MVD (r = 0.683, P = 0.001). We conclude that HIF-1alpha is overexpressed in VX2 tumors treated with TAE as a result of intratumoral hypoxia generated by the procedure and involved in activation of the TAE-associated tumor angiogenesis. HIF-1alpha might represent a promising therapeutic target for antiangiogenesis in combination with TAE against liver tumors.

Influence of hepatic artery occlusion on tumor growth and metastatic potential in a human orthotopic hepatoma nude mouse model: relevance of epithelial-mesenchymal transition

Hepatic artery ligation (HAL), transarterial embolization (TAE), and transarterial chemoembolization (TACE) have been treatment choices for unresectable hepatocellular carcinoma (HCC). Obstruction of tumor blood supply is one of the most important mechanisms of these therapeutics measures. Here we introduced HAL into a metastatic human HCC orthotopic nude mouse model (using MHCC97L and HepG2 cell lines) to examine the effects of hepatic blood flow obstruction on the metastatic potential of hepatic tumor cells, and to investigate the mechanisms underlying these effects. Our results indicated that HAL inhibited tumor growth but concomitantly elicited tumor adaptation and progression, with increased potential for invasion and distant metastases. The underlying proinvasive mechanism of HAL appeared to be associated with enhanced intratumoral hypoxia and epithelial-mesenchymal transition (EMT) due to hypoxia. This was in accord with the in vitro response of MHCC97L and HepG2 cells to hypoxia. The therapeutic effects of HAL could be enhanced by the phosphatidyl inositol 3-kinase (PI3K) inhibitor LY294002, through arrest of EMT in hepatic tumor cells. It could be useful in the development of mechanism-based combination therapies to enhance the initial antitumor response.

Synergistic antitumor effects of transarterial viroembolization for multifocal hepatocellular carcinoma in rats

Oncolytic virotherapy is a promising strategy for safe and effective treatment of malignancy. We have reported previously that recombinant vesicular stomatitis virus (VSV) vectors are effective oncolytic agents that can be safely administered via the hepatic artery in immunocompetent rats to treat multifocal hepatocellular carcinoma (HCC), resulting in tumor necrosis and prolonged survival. Though the results were encouraging, complete tumor regression was not observed, which led us to explore alternative approaches to further enhance the efficacy of VSV treatment. Transarterial embolization techniques have been shown to improve the efficiency and tumor selectivity of anticancer treatments. Degradable starch microspheres (DSM) are one such embolic agent that provides transient embolization of the therapeautic agent before being degraded by serum amylases. Here we demonstrate via dynamic contrast-enhanced magnetic resonance imaging that in our rat model of multifocal HCC, DSM injection into the hepatic artery results in a substantial reduction in tumor perfusion of systemically applied contrast agent. VSV, when administered in combination with DSM, results in enhanced tumor necrosis and synergistically prolongs survival when compared with VSV or DSM monotherapy.

CONCLUSION

This regimen of viroembolization represents an innovative therapeutic modality that can augment the future development of transarterial oncolytic virus therapy for patients with advanced HCC.

Serial evaluations of myocardial infarct size after alcohol septal ablation in hypertrophic cardiomyopathy and effects of the changes on clinical status and left ventricular outflow pressure gradients

Alcohol septal ablation (ASA) as a treatment for obstructive hypertrophic cardiomyopathy produces septal infarction. There is a concern that such infarcts could be detrimental. Changes in the size of these infarcts by serial perfusion testing have not been studied. We performed resting serial-gated single-photon emission computed tomographic myocardial perfusion imaging in 30 patients (age 51+/-17 years, 57% were women) who had ASA between September 2003 and March 2007 before, 2+/-0.8 days (early), and 8.4+/-6.9 months (late) after ASA. Patients were also followed clinically and with serial 2-dimensional echocardiography. New York Heart Association class decreased from 3.50+/-0.51 before to 1.14+/-0.36 (p<0.0001) 3 months after ASA. The left ventricular (LV) outflow gradient (by Doppler echocardiography) decreased from 63+/-32 mm Hg before to 28+/-23 mm Hg after ASA (p<0.005). None of the patients had perfusion defects at rest before ASA. After ASA, perfusion defect size, involving the basal septum, decreased from 9.4+/-5.8% early to 5.2+/-4.2% of LV myocardium late after ASA (p<0.001). There were no changes in LV size and ejection fraction after ASA. In conclusion, ASA produces small basal ventricular septal infarcts (resting perfusion abnormality) involving<10% of the LV myocardium (including ventricular septum). There is a significant reduction in the perfusion abnormality late after ASA without an increase in LV outflow obstruction or recurrence of symptoms.