Isolated hepatic perfusion: principles and results

TLR5 agonist entolimod reduces the adverse toxicity of TNF while preserving its antitumor effects

Tumor necrosis factor alpha (TNF) is capable of inducing regression of solid tumors. However, TNF released in response to Toll-like receptor 4 (TLR4) activation by bacterial lipopolysaccharide (LPS) is the key mediator of cytokine storm and septic shock that can cause severe tissue damage limiting anticancer applications of this cytokine. In our previous studies, we demonstrated that activation of another Toll-like receptor, TLR5, could protect from tissue damage caused by a variety of stresses including radiation, chemotherapy, Fas-activating antibody and ischemia-reperfusion. In this study, we tested whether entolimod could counteract TNF-induced toxicity in mouse models. We found that entolimod pretreatment effectively protects livers and lungs from LPS- and TNF-induced toxicity and prevents mortality caused by combining either of these agents with the sensitizer, D-galactosamine. While LPS and TNF induced significant activation of apoptotic caspase 3/7, lipid tissue peroxidation and serum ALT accumulation in mice without entolimod treatment, these indicators of toxicity were reduced by entolimod pretreatment to the levels of untreated control mice. Entolimod was effective when injected 0.5–48 hours prior to, but not when injected simultaneously or after LPS or TNF. Using chimeric mice with hematopoiesis differing in its TLR5 status from the rest of tissues, we showed that this protective activity was dependent on TLR5 expression by non-hematopoietic cells. Gene expression analysis identified multiple genes upregulated by entolimod in the liver and cultured hepatocytes as possible mediators of its protective activity. Entolimod did not interfere with the antitumor activity of TNF in mouse hepatocellular and colorectal tumor models. These results support further development of TLR5 agonists to increase tissue resistance to cytotoxic cytokines, reduce the risk of septic shock and enable safe systemic application of TNF as an anticancer therapy.

Isolated hepatic perfusion for unresectable hepatic malignancies: A systematic review and meta-analysis

AIM

To investigate the efficacy and safety of isolated hepatic perfusion (IHP) in the management of unresectable liver malignancies.

METHODS

Studies were identified manually and on-line by using PubMed and EMBASE database. We formulate the eligibility criteria according to the PICOS elements, and accessed the quality of studies using the MINORS instrument. Data from all included studies were carefully investigated. We calculated the pooled response rate and incidences of mortality reported from all eligible studies by using the Meta-Analyst software, and we computed a pooled relative risk (RR) and 95%CI by using the Comprehensive Meta-Analysis software. Heterogeneity was quantified evaluated using I² statistic.

RESULTS

Eight studies, including 502 patients, were selected. Of these, six studies performed IHP, while the other two studies performed percutaneous IHP. The results showed that the pooled response rate was 60.8% (95%CI: 53.1%-68%), I² = 37.1%. The median overall survival was 20 mo (range: 12.1 to 25 mo) following IHP or PIHP. The pooled mortality rate was 5.4% (95%CI: 2.5%-11.2%), I² = 37.5%. Prognostic factors predict the response to IHP or survival, and were reported in six studies. Meta-analysis demonstrated that Gender was not associated with overall survival (RR = 0.877, 95%CI: 0.564-1.365); however, carcino-embryonic antigen ≤ 30 ng/mL was associated with a significant improvement in survival outcomes with colorectal cancer patients (RR = 2.082, 95%CI: 1.371-3.163), and there was no significant heterogeneity.

CONCLUSION

The present systemic review and meta-analysis suggest that IHP and PIHP are potentially efficient and safe techniques for unresectable liver primary and secondary malignancies.

Percutaneous Isolated Hepatic Perfusion for the Treatment of Unresectable Liver Malignancies

Liver malignancies are a major burden of disease worldwide. The long-term prognosis for patients with unresectable tumors remains poor, despite advances in systemic chemotherapy, targeted agents, and minimally invasive therapies such as ablation, chemoembolization, and radioembolization. Thus, the demand for new and better treatments for malignant liver tumors remains high. Surgical isolated hepatic perfusion (IHP) has been shown to be effective in patients with various hepatic malignancies, but is complex, associated with high complication rates and not repeatable. Percutaneous isolated liver perfusion (PHP) is a novel minimally invasive, repeatable, and safer alternative to IHP. PHP is rapidly gaining interest and the number of procedures performed in Europe now exceeds 200. This review discusses the indications, technique and patient management of PHP and provides an overview of the available data.