Single- versus Triple-Drug Chemoembolization for Hepatocellular Carcinoma: Comparing Outcomes by Toxicity, Imaging Response, and Survival

Drug delivery in transarterial chemoembolization of hepatocellular carcinoma: Ex vivo evaluation using transparent tissue imaging

In this study, we elucidated for the first time the role of anti-cancer drugs in transarterial chemoembolization (TACE) via direct visualization of the spatial distribution of drugs with respect to blood vessels in intact transparent hepatocellular carcinoma (HCC) tissues. To date, precise estimation of drug penetration into tumors using thin 3D tissue sections has been challenging. This study utilized the tissue optical clearing technique to resolve the lack of tissue clarity, thereby enabling deep tissue imaging for the quantitative assessment of drug delivery following TACE. We compared the drug delivery effect, time-dependent embolic effect, and immunogenic response following conventional TACE (cTACE), drug-eluting embolic TACE (DEE-TACE), and transarterial embolization (TAE) in a rat model of HCC. After each treatment, three-dimensional drug delivery was quantitatively evaluated via the transparent liver tumor imaging, and time-dependent tumor necrosis was analyzed by serial tumor harvesting and histological staining. The results showed that chemotherapeutic agents travel only short distances after cTACE (∼80µm) and DEE-TACE (∼110µm), whereas necrosis occurs extensively within 24 h of treatment (85.3-97.2% of tumor cells). In addition, the percentages of CD4 and IL-17+ CD4 T cells increased significantly following treatment; however, drug-loading did not appear to affect the immune response following TACE. In conclusion, transarterially delivered chemotherapeutic agents appeared to exert a limited role, owing to the rapid and overwhelming effect of embolization. STATEMENT OF SIGNIFICANCE: TACE has been widely used for the treatment of HCC, especially for unresectable intermediate and advanced HCCs. Drug use in TACE is expected to provide patients with synergistic therapeutic benefits with the effect of embolic agents; however, the role of chemotherapeutic agents in TACE remains controversial. This study quantitatively verified that chemotherapeutic agents travel only short distances after TACE, while necrosis occurs extensively within 24h, and drug loading does not significantly affect immune responses following TACE. Three-dimensional imaging of intact transparent HCC can contribute to a better understanding of drug delivery mechanisms associated with TACE and also reveal that drug use in TACE may need to be reconsidered and limited to situations when embolization is expected to be insufficient.

Gas generating microspheres for immediate release of Hsp90 inhibitor aiming at postembolization hypoxia in transarterial chemoembolization therapy of hepatocellular carcinoma

CO₂ gas generating poly(lactic-co-glycolic acid) (PLGA) microsphere (MS) was designed for rapid release of tanespimycin (17-AAG) in transarterial chemoembolization (TACE) treatment of hepatocellular carcinoma (HCC). As poorly water-soluble drug is generally released from PLGA MS in a sustained manner, the drug release profile should be controlled according to its clinical indications. In current study, responding to immediate increase in hypoxia inducible factor-1α (HIF-1α) level under hypoxia state followed by embolization of tumor feeding arteries, sodium bicarbonate (NaHCO₃) was added to PLGA/17-AAG MS for fast drug release by CO₂ gas generation in slightly acidic tumor microenvironment. With the aid of NaHCO₃, initial burst release of 17-AAG was available without losing the micron-size and spherical shape of designed MS for embolization of artery. Acid-responsive CO₂ gas generation and subsequent immediate release of 17-AAG from MS were successfully verified. PLGA/17-AAG/NaHCO₃ MS-treated group exhibited higher antiproliferation and apoptosis induction efficacies in McA-RH7777 and SNU-761 cells. McA-RH7777 tumor-implanted rats treated by TACE using PLGA/17-AAG/NaHCO₃ MS presented a complete therapeutic response. All these findings suggest that developed tumor microenvironment-responsive gas-generating MS can be efficiently applied to TACE therapy of HCC.

Incidence and risk factors for sustained hepatic function toxicity 6 months after radioembolization: analysis of the radiation-emitting sir-spheres in non-resectable liver tumor (RESIN) registry

Background

To quantify rates and risk factors for toxicity after hepatic radioembolization using resin yttrium-90 microspheres.

Methods

Radiation-Emitting SIR-Spheres in Non-resectable liver tumor (RESIN) registry enrollees were reviewed with 614 patients included. Mean patient age was 63.1±12.5 years. The majority of patients were male (n=375, 61%) and white (n=490, 80%). Common tumor types were hepatocellular (n=197, 32%), colorectal (n=187, 30%) and neuroendocrine (n=56, 9%). Hepatotoxicity was measured using the Common Terminology Criteria for Adverse Events (CTCAE v 5). Potential risk factors for hepatotoxicity were tested using the Kruskal-Wallis or Pearson Chi-squared tests, and multivariate linear regressions.

Results

At 6 months, 115 patients (18.7%) died (n=91, 14.8%), entered hospice (n=20, 3.3%) or sought treatment elsewhere (n=4, 4%). Seven (1.1%) deaths were from liver decompensation. Grade 3 toxicity rates were: bilirubin (n=85, 13.8%), albumin (n=28, 4.6%), ALT (n=26, 4.2%) and AST (n=37, 6.0%). For each of these liver function test components, baseline abnormal labs predicted Grade 3 toxicity at follow-up by Kruskal-Wallis test (P<0.001) and linear regression (all P<0.03). Other significant factors predicting toxicity at regression included elevated Body-Mass Index (albumin P=0.0056), whole liver treatment (bilirubin P=0.046), and lower tumor volume (ALT and INR, P<0.035 for both).

Conclusions

Baseline liver function abnormalities prior to radioembolization is the strongest predictor of post-treatment Grade 3 toxicity with rates as high as 13.8%. Toxicity rates for specific lab values are affected by large volume treatments especially with low tumor volumes.

Clinical Case Panel: Treatment Alternatives for Inoperable Hepatocellular Carcinoma

Surgical resection or liver transplantation offers the best chance of cure for patients with hepatocellular carcinoma (HCC). Unfortunately, most patients are not good candidates for liver resection due to locally advanced disease or compromised liver function. Moreover, liver transplantation waiting lists are long. For those cases not amenable for resection, a variety of local treatment modalities are available, such as image-guided ablative procedures, transarterial chemoembolization, and radioembolization, as well as external beam radiation. HCC presentation can vary considerably in size, number, and location of lesions. The management of inoperable HCC is, therefore, quite complex, and there is a lack of consensus on the best local treatment modality for each type tumor presentation. Here, we present 4 clinical case scenarios representative of commonly seen cases in the clinical setting, with different therapeutic perspectives from institutions with high expertise in the management of HCC.

MicroRNA-493-5p promotes apoptosis and suppresses proliferation and invasion in liver cancer cells by targeting VAMP2

The aim of the present study was to explore the role of miR‑493-5p in liver cancer tissues and cell lines, and its effect on cell behavioral characteristics. The expression of miR-493-5p was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in liver cancer tissues and cell lines (hepatic cell line HL-7702 and the liver cancer cell lines HCCC-9810, HuH-7 and HepG2). In addition, the mechanism by which miR-493-5p mediates its effects was analyzed via the transfection of miR-493-5p mimic and negative control miRNA into HepG2 cells. The viability, proliferation, apoptosis and invasion of the cells were analyzed using MTT assay, flow cytometry and Transwell chamber experiments. Furthermore, the effect of miR-493-5p on the expression of vesicle associated membrane protein 2 (VAMP2) was assayed using a dual-luciferase reporter system, and VAMP2 protein levels were determined by western blot analysis. In addition, following the cotransfection of HepG2 cells with pcDNA3.1‑VAMP2 plasmid and miR‑493-5p mimic, the role of miR-493-5p as a regulator of VAMP2 was evaluated using MTT assay, flow cytometry and Transwell chamber experiments. RT-qPCR analysis indicated that the expression of miR-493-5p in liver cancer tissues and cell lines was decreased significantly compared with that in adjacent normal liver tissues and normal liver cell lines, respectively. Compared with the control group, the cells transfected with miR-493-5p mimic (the miR-493-5p overexpression group) exhibited reduced cell viability, a reduced percentage of cells in the S phase and an increased percentage of apoptotic cells. In addition, fewer cells passed through the Transwell membrane in the miR-493-5p overexpression group compared with the control group. In the dual-luciferase reporter assay, luciferase activity in the miR‑493-5p overexpression group was attenuated compared with that in the control group. In addition, western blot analysis indicated that the VAMP2 protein levels in the miR‑493-5p overexpression group were lower than those in the control group. Furthermore, in cells overexpressing miR-493-5p and VAMP2 simultaneously, the biological behavior of the cells, including cell viability, cell cycle and cell invasiveness, was significantly rescued compared with that of the control group transfected with miR‑493-5p alone. In conclusion, miR-493-5p is indicated to be a tumor suppressor gene, and is downregulated in human liver cancer. miR-493-5p overexpression promotes cell apoptosis and inhibits the proliferation and migration of liver cancer cells by negatively regulating the expression of VAMP. These observations suggest the potential of treating liver cancer by the overexpression of microRNA-493-5p.

Pretransplant Intra-arterial Liver-Directed Therapy Does Not Increase the Risk of Hepatic Arterial Complications in Liver Transplantation: A Single-Center 10-Year Experience

PURPOSE

To investigate the association between pretransplant intra-arterial liver-directed therapy (IAT) for hepatocellular carcinoma (HCC) and hepatic arterial complications (HAC) in orthotopic liver transplantation (OLT) [namely hepatic artery thrombosis (HAT) and/or the need for hepatic arterial conduit].

METHODS

A total of 175 HCC patients (mean age: 60 years) underwent IAT with either transarterial chemoembolization or yttrium-90 (90Y) transarterial radioembolization prior to OLT between 2003 and 2013. A matched control cohort of 159 HCC patients who underwent OLT without prior IAT was selected. Incidence of HAC in both cohorts was investigated. The categorical differences between both cohorts were calculated by chi-square test.

RESULTS

Among the 175 patients (chemoembolization, n = 82; radioembolization, n = 93), 8 (5%) required conduits due to HA disease (chemoembolization, n = 6; radioembolization, n = 2), 3 (2%) developed HAT (chemoembolization, n = 2; radioembolization, n = 1). Eleven of 175 patients (6.7%) had HAC. Of the 159 control patients, 6 (4%) needed conduits for HA disease and 3 (2%) developed HAT. Nine of 159 patients (5.7%) had HAC. Chi-square analysis between the IAT cohort and the control group yielded a p value of 0.810. When comparing chemoembolization to radioembolization, p = 0.076 (not significant at p < 0.05).

CONCLUSION

Although aggressive pretransplant radioembolization and chemoembolization are both utilized in most liver transplant centers, neither appears to increase the risk of peri-transplant hepatic arterial complications in HCC patients.