Isolated organ perfusion does not result in systemic microembolization of tumor cells

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.

Circulating tumor cells and bone marrow micrometastasis

Sensitive immunocytochemical and molecular assays allow the detection of single circulating tumor cells (CTC) in the peripheral blood and disseminated tumor cells (DTC) in the bone marrow as a common and easily accessible homing organ for cells released by epithelial tumors of various origins. The results obtained thus far have provided direct evidence that tumor cell dissemination starts already early during tumor development and progression. Tumor cells are frequently detected in the blood and bone marrow of cancer patients without clinical or even histopathologic signs of metastasis. The detection of DTC and CTC yields important prognostic information and might help to tailor systemic therapies to the individual needs of a cancer patient. In the present review, we provide a critical review of (a) the current methods used for detection of CTC/DTC and (b) data on the molecular characterization of CTC/DTC with a particular emphasis on tumor dormancy, cancer stem cell theory, and novel targets for biological therapies; and we pinpoint to (c) critical issues that need to be addressed to establish CTC/DTC measurements in clinical practice.

The Past Decade of Experience With Isolated Hepatic Perfusion

Metastatic or primary unresectable cancers confined to the liver are the sole or life-limiting component of disease for many patients with colorectal cancer, ocular melanoma, neuroendocrine tumors, or primary colangio- or hepatocellular carcinomas. Regional treatment strategies including infusional chemotherapy and local ablative therapy are under investigation, but have limitations with respect to the clinical conditions under which they can be employed. Isolated hepatic perfusion (IHP) was first clinically applied over 40 years ago, but because of its technical complexity, the attendant potential morbidity, and the lack of documented efficacy, it has not enjoyed consistent or widespread evaluation. In light of the antitumor activity with isolated limb perfusion with tumor necrosis factor (TNF) and melphalan in patients with unresectable extremity sarcoma or in transit melanoma, this regimen has been administered via IHP at several centers worldwide for patients with unresectable liver cancers. IHP with TNF and melphalan can result in significant regression of advanced refractory cancers from multiple histologies confined to the liver. Patient selection is important to ensure good results with minimal morbidity and mortality. Work to define the appropriate clinical groups is ongoing at many clinical centers.

Isolation perfusion of the liver

Thousands of patients die annually from unresectable metastatic or primary hepatic cancers confined to liver. Isolated hepatic perfusion (IHP) is a regional treatment strategy in which the vascular supply to the liver is isolated and perfused with a therapeutic regimen using an extracorporeal circuit consisting of a reservoir, heat exchanger, and oxygenator. Drug doses that would cause severe toxicities if delivered systemically can be confined to the liver by isolated hepatic perfusion, resulting in the ability to intensify treatment to the cancer-burdened region of the body. Agents and mechanisms commonly used in IHP include melphaIan, hyperthermia, and tumor necrosis factor. IHP appears to be efficacious for patients with advanced disease, as reflected by large tumor size, high number of lesions, or significant overall tumor burden in the liver. In addition, responses are observed for patients whose cancer is refractory to systemic and hepatic arterial infusion chemotherapy. Recent clinical trials have demonstrated that IHP has anti-tumor efficacy against primary hepatic neoplasms and metastases from various primary tumors, such as colorectal carcinoma, ocular melanoma, and neuroendocrine tumors. Current studies demonstrate that combining hepatic arterial infusion with floxuridine after IHP for patients with colorectal cancer metastases is associated with significant and durable response rates. Continued clinical evaluation is warranted for the use of IHP in the treatment of unresectable liver metastases.

Serological markers for melanoma

We present a review of current literature concerning the significance of serological markers in melanoma patients. Results for cytokines, cytokine receptors, cell adhesion molecules, S100 protein, melanoma inhibitory activity, tissue-specific reverse transcription-polymerase chain reaction, neurone-specific enolase, lipid-bound sialic acid and melanin metabolites such as 5-S-cysteinyldopa and 6-hydroxy-5-methoxyindole-2-carboxylic acid are discussed. For most of these substances, serum levels are more pronounced in the more advanced stages of disease. Therefore, these markers seem to have no place in the early detection of melanoma. On the other hand, sensitivity in the advanced stages of disease seems to be < 100%, compromising their use as a new staging procedure. Some markers show promising results as a possible prognostic factor in the early detection of disease progression or in the prediction of therapy outcome. If confirmed by further studies, this could direct future therapeutic strategies and could help to select patients who would benefit most from more aggressive (adjuvant) therapies. In addition, the study of some of these substances could add to the knowledge of tumour biology and immunology.