Current Role of Hepatic Artery Infusion and Isolated Liver Perfusion for the Treatment of Colorectal Cancer Liver Metastases

Locoregional intravascular viral therapy of cancer: precision guidance for Paris's arrow?

Viral therapy of cancer includes strategies such as viral transduction of tumour cells with 'suicide genes', using viral infection to trigger immune-mediated tumour cell death and using oncolytic viruses for their direct anti-tumour action. However, problems still remain in terms of adequate viral delivery to tumours. A role is also emerging for single-organ isolation and perfusion. Having begun with the advent of isolated limb perfusion for extremity malignancy, experimental systems have been developed for the perfusion of other organs, particularly the liver, kidneys and lungs. These are beginning to be adopted into clinical treatment pathways. The combination of these two modalities is potentially significant. Locoregional perfusion increases the exposure of tumour cells to viral agents. In addition, the avoidance of systemic elimination through the immune and reticulo-endothelial systems should provide a mechanism for increased transduction/infection of target cells. The translation of laboratory research to clinical practice would occur within the context of perfusion programmes, which are already established in the clinic. Many of these programmes include the use of vasoactive cytokines such as tumour necrosis factor-alpha, which may have an effect on viral uptake. Evidence of activation of specific anti-tumour immunological responses by intratumoural and other existing methods of viral administration raises the intriguing possibility of a locoregional therapy, with the ability to affect distant sites of disease. In this review, we examined the state of the literature in this area and summarized current findings before indicating likely areas of continuing interest.

Regional chemotherapy: overview

Regional chemotherapy was developed in the 1950s and continues to play an integral part in the development of newer therapies for advanced solid malignancies. Regional therapies have evolved in complexity but are still based on the pharmacokinetics of drug delivery to solid malignancies. Newer techniques demonstrate that the combination of regional therapies, hyperthermia, and surgery is essential in promoting improved patient outcomes.

Sendai virus-mediated gene delivery into hepatocytes via isolated hepatic perfusion

The recombinant Sendai virus vector is a promising tool for human gene therapy, capable of inducing high-level expression of therapeutic genes in tissue cells in situ. The target tissues include airway epithelium, blood vessels, skeletal muscle, retina and the central nervous system, but application to hepatic tissues has not yet been achieved, because direct intraportal injection of the vector is not feasible. We report an efficient and harmless procedure of gene delivery by recombinant Sendai virus into rat parenchymal hepatocytes, based on isolated hepatic perfusion with controlled inflow. Critical parameters for successful hepatic gene delivery are a brief preperfusion period (25 degrees C, 5 min); appropriate vector concentration in the perfusate (10(7) pfu/ml); moderate portal vein pressure (12 mmHg) and a brief hyperthermic postperfusion period (42 degrees C, 5 min). Under these optimized conditions, marker genes were expressed in most parenchymal hepatocytes without significant damage to hepatic tissues. Furthermore, expression of the marker genes was undetectable in nonhepatic tissues, including the gonads, indicating that this approach strictly targets hepatic tissues and thus offers good clinical potential for human gene therapy.

A Complication-Free Course Ensures a Survival Advantage in Patients after Regional Therapy for Metastatic Colorectal Cancer

Hepatic artery infusional (HAI) chemotherapy has been shown to favorably impact outcome in patients with metastatic colorectal cancer, but complications often preclude complete treatment. The purpose of this study was to determine whether HAI complications impact survival in these patients. Patients undergoing HAI pump placement at our institution from September 2001 to July 2004 were separated into terciles based on the number of treatments completed: ≤1 (none), 2 to 4 (partial), and ≥5 (complete). Complications relating to pump placement or treatment were recorded for each and their impact on survival was determined. Kaplan-Meier survival in 15 patients receiving no treatment was significantly shorter than 7 patients completing therapy (P = 0.02). Thirty-three per cent of patients receiving no therapy were alive at 26 months, whereas 63 per cent of partially and 86 per cent of completely treated patients were alive at 32 and 30 months, respectively. Patients receiving no treatment had more overall complications (80%) and significantly (P < 0.05) more pump-related complications (60%) than those completing therapy (43% and 0%, respectively). Cox regression revealed a significant correlation to gender (hazard ratio, 3.9), tumor size (hazard ratio, 1.17), and carcinoembryonic antigen level (hazard ratio, 1.02) to survival. Patients receiving complete HAI treatment survive longer than those receiving no treatment. Potentially preventable pump-related complications not only impacted the patients’ ability to continue therapy, but survival times as well.

Leberkarzinome und Lebermetastasen

High dosage regional chemotherapy, chemoembolization and other methods of regional treatment are commonly used to treat unresectable primary liver malignancies and liver metastases. In liver malignancies of childhood neoadjuvant chemotherapy is successfully combined with surgical treatment. Chemotherapy and local tumor ablation lead to characteristic histomorphologic changes: Complete destruction of the tumor tissue and its vascular bed is followed by encapsulated necroses. After selective eradication of the tumor cells under preservation of the fibrovasular bed the tumor is replaced by hypocellular edematous and fibrotic tissue. If completely damaged tumor tissue is absorbed quickly, the tumor area is replaced by regenerating liver tissue. Obliterating fibrohyalinosis of tumor vessels, and perivascular edema or necrosis indicate tissue damage along the vascular bed. Degenerative pleomorphism of tumor cells, steatosis, hydropic swelling and Malloryhyalin in HCC can represent cytologic findings of cytotoxic cellular damage. Macroscopic type of HCC influences significantly the response to treatment. Multinodular HCC often contain viable tumor nodules close to destroyed nodules after treatment. Encapsulated uninodular tumors undergo complete necrosis much easier. Large size and a tumor capsule limitate the effect of percutaneous injection of ethanol into HCC. In carcinomas with an infiltrating border, especially in metastases of adenocarcinomas and hepatic cholangiocarcinoma cytostatic treatment damages the tumor tissue mainly in the periphery. Nevertheless the infiltrating rim, portal veins, lymphatic spaces and bile ducts as well as the angle between liver capsule, tumor nodule and bordering parenchyma are the main refugees of viable tumor tissue even after high dosage regional chemotherapy. This local resistance is caused by special local conditions of vascularization and perfusion. These residues are the source of local tumor progression and distant metastases. Besides intrinsic cellular mechanisms architectural, and microenvironmental factors relevantly limitate the effect of intensive locoregional therapy.

Predictors of survival after radiofrequency thermal ablation of colorectal cancer metastases to the liver: a prospective study

PURPOSE

The aim of this study was to determine the predictors of survival at the time of radiofrequency thermal ablation (RFA) in patients with colorectal liver metastasis.

PATIENTS AND METHODS

One hundred thirty-five patients with colorectal liver metastases who were not candidates for resection underwent laparoscopic RFA.

RESULTS

The median Kaplan-Meier survival for all patients was 28.9 months after RFA treatment. Patients with a carcinoembryonic antigen (CEA) less than 200 ng/mL had improved survival compared with those with a CEA more than 200 (34 v 16 months; P = .01). Patients with the dominant lesion less than 3 cm in diameter had a median survival of 38 v 34 months for lesions 3 to 5 cm, and 21 months for lesions greater than 5 cm (P = .03). Survival approached significance for patients with one to three tumors versus more than three tumors (29 v 22 months; P = .09). The presence of extrahepatic disease did not affect survival. Only the largest liver tumor size more than 5 cm was found to be a significant predictor of mortality by Cox proportional hazards model, with a 2.5-fold increased risk of death versus the largest liver tumor size less than 3 cm (P = .05).

CONCLUSION

This study determines which patients do best after RFA. Historical survival with chemotherapy alone is 11 to 14 months, suggesting RFA has a positive impact on overall survival. Limited amounts of extrahepatic disease do not appear to affect survival adversely. RFA is a useful adjunct to chemotherapy in those patients with liver-predominant disease.