Isolated hepatic perfusion with tumor necrosis factor alpha and melphalan: experimental studies in pigs and phase I data from humans

Chemosaturation Percutaneous Hepatic Perfusion: A Systematic Review

The Hepatic CHEMOSAT® Delivery System is an innovative medical device for the treatment of patients with unresectable primary liver tumors or unresectable hepatic metastases from solid organ malignancies. This system is used to perform chemosaturation percutaneous hepatic perfusion (CS-PHP), a procedure in which a high dose of the chemotherapeutic agent melphalan is delivered directly to the liver while limiting systemic exposure. In a clinical trial program, CS-PHP with melphalan significantly improved hepatic progression-free survival in patients with unresectable hepatic metastases from ocular or cutaneous melanoma. Clinically meaningful hepatic responses were also observed in patients with hepatocellular carcinoma or neuroendocrine tumors. Furthermore, the results of published studies and case reports demonstrated that CS-PHP with melphalan resulted in favorable tumor response rates in a range of tumor histologies (ocular or cutaneous melanoma, colorectal cancer, and hepatobiliary tumors). Analyses of the safety profile of CS-PHP revealed that the most common adverse effects were hematologic events (thrombocytopenia, anemia, and neutropenia), which were clinically manageable. Taken together, these findings indicate that CS-PHP is a promising locoregional therapy for patients with primary and secondary liver tumors and has a acceptable safety profile.

FUNDING

Delcath Systems Inc., New York, NY, USA.

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.

Hemodynamics in rat liver tumor model during retrograde-outflow isolated hepatic perfusion with aspiration from the portal vein: angiography and in vivo microscopy

BACKGROUND

Orthograde percutaneous isolated hepatic perfusion (IHP) techniques using balloon occlusion catheters are relatively simple and facilitate repeated therapy, but they result in higher rates of leakage from the perfusion circuit into the systemic circulation. Therefore, a feasible protocol for percutaneous IHP with less leakage is required.

PURPOSE

To investigate hemodynamic changes in rat liver and tumor during retrograde-outflow isolated hepatic perfusion (R-IHP) with aspiration from the portal vein (PV).

MATERIAL AND METHODS

Animal experiments were approved by the Animal Experiment Ethics Committee of Lund University. Eighteen rats underwent R-IHP after laparotomy and catheterization of the PV and hepatic artery (HA). The HA, inferior vena cava (IVC), and PV were ligated, and flow through the suprahepatic IVC was controlled with a suture loop. The rats were divided into two groups to examine blood flow during R-IHP. Four rats (group 1) underwent arteriography via the HA with and without R-IHP, and 14 rats (group 2) were inoculated with tumor and examined by in vivo fluorescence microscopy of liver and tumor during R-IHP.

RESULTS

In group 1, hepatic arteriography during R-IHP confirmed arterioportal communication in all four rats, with the PV acting as an outflow tract. In vivo fluorescence microscopy in group 2 showed strong enhancement of tumors, and no blood supply from the portal venules to the tumors was seen in any of the 14 rats. Blood flow in the major portion of the hepatic lobules was stopped and the percentage of enhanced area was significantly lower in the normal hepatic lobules than in the tumors (P < 0.0001).

CONCLUSION

We confirmed reversal of blood flow concomitant with good perfusion of the liver tumor and with reduced perfusion of normal liver parenchyma during R-IHP.

Recent trends and future perspectives in isolated hepatic perfusion in the treatment of liver tumors

Isolated hepatic perfusion (IHP) involves a method of complete vascular isolation of the liver to enable treatment of liver tumors with high drug doses without systemic toxicity. Recent clinical studies have mainly employed IHP with melphalan with or without tumor necrosis factor-alpha and mild hyperthermia. The results of these studies demonstrate that high response and survival rates can be achieved with IHP. The current status, recent developments and future perspectives of IHP are discussed in this review.

Selective protection of human liver tissue in TNF-targeting of cancers of the liver by transient depletion of adenosine triphosphate

BACKGROUND

Tumor necrosis factor alpha (TNF) is able to kill cancer cells via receptor-mediated cell death requiring adenosine triphosphate (ATP). Clinical usage of TNF so far is largely limited by its profound hepatotoxicity. Recently, it was found in the murine system that specific protection of hepatocytes against TNF's detrimental effects can be achieved by fructose-mediated ATP depletion therein. Before employing this quite attractive selection principle in a first clinical trial, we here comprehensively investigated the interdependence between ATP depletion and TNF hepatotoxicity in both in vitro and ex vivo experiments based on usage of primary patient tissue materials.

METHODS

Primary human hepatocytes, and both non-tumorous and tumorous patient-derived primary liver tissue slices were used to elucidate fructose-induced ATP depletion and TNF-induced cytotoxicity.

RESULTS

PHH as well as tissue slices prepared from non-malignant human liver specimen undergoing a fructose-mediated ATP depletion were both demonstrated to be protected against TNF-induced cell death. In contrast, due to tumor-specific overexpression of hexokinase II, which imposes a profound bypass on hepatocytic-specific fructose catabolism, this was not the case for human tumorous liver tissues.

CONCLUSION

Normal human liver tissues can be protected transiently against TNF-induced cell death by systemic pretreatment with fructose used in non-toxic/physiologic concentrations. Selective TNF-targeting of primary and secondary tumors of the liver by transient and specific depletion of hepatocytic ATP opens up a new clinical avenue for the TNF-based treatment of liver cancers.

Hypoxic single-pass isolated hepatic perfusion of hypotonic Cisplatin: safety study in the pig

BACKGROUND

Isolated hepatic perfusion (IHP) of chemotherapy has been proposed to deliver high doses of drug while avoiding systemic toxicity. Hypotonic cisplatin has a high in vitro activity on human colon cancer cells. We studied the safety of a 30-min hypoxic single-pass IHP with hypotonic cisplatin.

METHODS

A preliminary in vitro assay was performed to compare the cytotoxicity of cisplatin and oxaliplatin, in either a normotonic or hypotonic medium. Cisplatin in hypotonic medium was then chosen for the in vivo IHP. Eleven pigs underwent 30 min of IHP with 0, 50, 75, or 100 mg/L of cisplatin in a hypotonic solution under total vascular exclusion of the liver. Clinical and biological parameters were recorded for 30 days, and liver histology was performed at necropsy. The cytotoxic activity of the effluent against resistant human colon cancer cells was tested in vitro.

RESULTS

No hepatic failure was recorded after IHP with cisplatin, but limited foci of necrosis were found at necropsy in animals receiving 75 or 100 mg/L of cisplatin. No clinical, biological, macroscopic, or microscopic toxicity was observed after IHP with 50 mg/L of hypotonic cisplatin. The liver effluent showed high in vitro cytotoxic activity against colon cancer cells.

CONCLUSIONS

A hypoxic single-pass isolated liver perfusion with hypotonic cisplatin is feasible and safe. Effluent from the liver is highly cytotoxic on cancer cells. A clinical study with 50 mg/L of hypotonic cisplatin is warranted in patients with unresectable liver metastases from colon cancer.

Isolated hepatic perfusion for the treatment of liver tumors: sunset or sunrise?

Experience with isolated hepatic perfusion (IHP) is limited to a few centers in the world because of the technical difficulties, surgery-related morbidity, and unproved efficacy in randomized trials. Experimental animal IHP models have led to exploring new ways of improving efficacy, reducing technical difficulties, and minimizing regional and systemic toxicity. Future research should be directed to the identification of suitable biologic or chemotherapeutic agents, defining clinical indications, and development of technical modifications to make it more generally applicable and even repeatable.

Isolated hypoxic hepatic perfusion with melphalan in patients with irresectable ocular melanoma metastases

AIM

Ocular melanoma prefers to metastasize to the liver and the liver is the sole site of metastatic disease in 80% of patients. Until now there has been no standard treatment available and these patients have a very poor prognosis (median survival 2-5 months). Isolated hepatic perfusion may be an option in patients with irresectable hepatic ocular melanoma metastases. The aim of this study was to evaluate applicability, toxicity and response in this selected group of ocular melanoma patients by treatment with isolated hypoxic hepatic perfusion with retrograde outflow (IHHP) with melphalan.

METHODS

From September 2002 until July 2006 eight consecutive patients were included in this study. IHHP was performed with inflow via the hepatic artery and retrograde outflow via the portal vein during 25 min with 1mg/kg melphalan. The perfusion was followed by a complete wash-out procedure.

RESULTS

The median total operation time was 4h with a median blood/fluid loss of 1100 ml. No postoperative mortality was observed. Median hospital stay was 9.5 days. Toxicity was moderate: WHO grade 3 leukocytopenia in 3 patients, grade 3 hepatic toxicity in 1 patient. In 37% of patients (3/8) a partial response could be demonstrated 3 months after IHHP. Stable disease was found in 3 patients and progressive disease in 2 patients. Median time to local progression was 6 months and the median survival was 11 months.

CONCLUSION

Melphalan-based IHHP with retrograde outflow is a safe treatment option for patients with irresectable ocular melanoma metastases. Survival benefit seems to be comparable to classical IHHP.

Laboratory models of regional chemotherapy

Development of new treatment strategies and agents is a difficult and costly matter in oncology. Routinely drugs are tested in vitro on tumor cells which, however, may have limited predictive value for their activity in patients. Also, the pharmacokinetic behavior, intratumoral distribution, as well as toxic side effects, binding to other compounds and stability of an agent are very important in determining activity in the patient. More so, development and evaluation of surgical delivery methods, i.e. regional treatment strategies, cannot be tested in cell systems. Therefore animal models are crucial for the development of regional chemotherapy methodologies. To allow translation of the animal data to patients it is important that the animal model closely mimics the clinical setting as for instance is achieved with isolated limb perfusion. However, animal models remain limited in their use, as eventually the efficacy of the approach may be different in animals compared to patients. Here we describe the use of animal models for regional treatment of solid tumors.

Isolated hypoxic hepatic perfusion with retrograde outflow in patients with irresectable liver metastases; a new simplified technique in isolated hepatic perfusion

Background

Isolated hepatic perfusion with high-dose chemotherapy is a treatment option for patients with irresectable metastases confined to the liver. Prolonged local control and impact on survival have been claimed. Major drawbacks are magnitude and costs of the procedure. We developed an isolated hypoxic hepatic perfusion (IHHP) with retrograde outflow without the need for a heart-lung machine.

Patients and Methods

Twenty-four consecutive patients with irresectable metastases of various origins were treated. IHHP inflow was via the hepatic artery, outflow via the portal vein with occlusion of the retrohepatic caval vein. Radiolabeled albumine was used for leakage monitoring. Melphalan was used at 1–2 mg/kg. A 25-minute perfusion period was followed by a complete washout. Local and systemic melphalan concentrations were determined.

Results

Compared with oxygenated classical IHP, the IHPP procedure reduced operation time from >8 h to 4 hours, blood loss from >4000 to 900 cc and saved material and personnel costs. Leakage was 0% with negligible systemic toxicity and 0% perioperative mortality. Tumor response: complete response (CR) in 4%, partial response (PR) in 58%, and stable disease (SD) in 13%. Median time to progression was 9 months (2–24 months); pharmacokinetics demonstrated intrahepatic melphalan concentrations more than 9 fold higher than postperfusion systemic concentrations.

Conclusions

IHPP is a relatively simple procedure with reduced costs, reduced blood loss, no mortality, limited toxicity, and response rates comparable to classic IHP. The median duration of 9 months of tumor control should be improved. Hereto, vasoactive drugs, will be explored in further studies.

Direct evidence for rapid and selective induction of tumor neovascular permeability by tumor necrosis factor and a novel derivative, colloidal gold bound tumor necrosis factor

Tumor necrosis factor (TNF) causes regression of advanced cancers when used in isolation perfusion with melphalan; evidence suggests these effects are mediated via selective yet uncharacterized actions on tumor neovasculature. A novel derivative, colloidal gold bound TNF (cAu-TNF) has been shown to have similar antitumor effects as native TNF with less systemic toxicity in mice. These studies were done to determine their effects on tumor neovasculature, using in vivo video microscopy. Female C57BL/6 mice bearing 20 mm(2) MC38 or LLC tumors that are TNF sensitive and resistant tumors, respectively, had dorsal skinfold chambers implanted. The rate of interstitial accumulation of Texas red fluorescently labeled albumin in tumor and normal vasculature was measured after intravenous TNF, cAu-TNF or PBS. Changes in interstitial fluorescent intensity over time were quantified as a reflection of alterations in vascular permeability. MC38 bearing mice treated with TNF or cAu-TNF demonstrated a rapid, selective and significant increase in tracer accumulation in areas of neovasculature compared to those of normal vasculature. Experiments in LLC tumor bearing mice showed similar results. Monoclonal antibody against tissue factor partially abrogated the effects of TNF on MC38 neovasculature. These data provide direct evidence that TNF and cAu-TNF selectively and rapidly alter permeability in tumor neovasculature; a phenomenon that may be exploited to enhance selective delivery of chemotherapeutics to tumor.

Correlation between melphalan pharmacokinetics and hepatic toxicity following hyperthermic isolated liver perfusion for unresectable metastatic disease

BACKGROUND

In the present work, we report on the results of our pilot study of hyperthermic isolated hepatic perfusion (IHP) with melphalan alone for patients with unresectable metastatic liver tumors refractory to conventional treatments, with particular regard to the correlation between pharmacokinetic findings and hepatic toxicity.

PATIENTS AND METHODS

Inclusion criteria were unresectable liver metastases, hepatic parenchyma replacement <or=50%, normal liver function, and previous failure of at least one conventional treatment. IHP was performed under hyperthermic conditions with melphalan (1.5 mg/kg body weight). Completeness of vascular isolation of the liver and drug distribution volumes of the perfusion circuit were assessed by a radiolabeled albumin-based method. Drug concentrations in perfusate and plasma were measured by means of high-performance liquid chromatography (HPLC).

RESULTS

Twenty patients with unresectable liver metastases underwent IHP. No intraoperative mortality occurred. Treatment-related systemic toxicity was minimal and reversible. Three patients (15%) experienced grade 4 hepatic toxicity and died due to liver failure and subsequent multiorgan failure. Other six patients had significant (grade 3-4) but transitory hepatic toxicity. Complete and partial responses were observed in three and nine out of 17 evaluable patients, respectively (overall response rate = 70%). The pharmacokinetics study showed a 3% mean perfusate-to-plasma drug leakage (range 1-6%). Logistic regression analysis showed that drug concentration in the perfusate circuit, but not preoperative tests, significantly and independently correlated with hepatic toxicity (P = 0.028).

CONCLUSIONS

Following melphalan-based IHP, objective tumor regression could be observed in a remarkable percentage of patients refractory to standard treatments. However, hepatic toxicity and related mortality were significant. Our findings suggest that drug dosage personalization based on the measurement of drug distribution volumes might minimize hepatic toxicity.

Synergistic antitumor effects of histamine plus melphalan in isolated hepatic perfusion for liver metastases

BACKGROUND

Nonresectable primary and metastatic liver tumors remain an important clinical problem. Melphalan-based isolated hepatic perfusion (M-IHP) leads to more than 70% objective responses in selective groups of patients with nonresectable metastases confined to the liver. Complete responses are rare and progression-free survival is limited. Tumor necrosis factor (TNF), a very active agent in isolated limb perfusion, is linked to serious hepatotoxicity, restricting its use in IHP. Because of its vasoactive properties, histamine (Hi) is an alternative to TNF. In this article we evaluate its potential synergistic effect in M-IHP, improving response rates.

METHODS

Our experimental rat IHP model is used for the treatment of soft tissue sarcoma liver metastases. Blood samples are collected for monitoring liver enzymes. Livers are excised 72 h and 7 days after treatment for histologic evaluation.

RESULTS

After sham-IHP and Hi-IHP, tumor progression was observed in 100% of treated animals, while after M-IHP this number fell to 62% and after Hi + M-IHP it fell to only 22% (P = 0.006). Overall response rates were of 55% for Hi + M-IHP vs. 25% for M-IHP, and, more importantly, complete responses (CR) were observed only after Hi + M-IHP (22%) (P = 0.009). Hepatotoxicity peaked within 24 h after IHP, independent of the treatment administered, recovered in 48 h, and was related mainly to the elevation of transaminases (grade 3 ASAT and grade 1 ALAT for control group and grades 3 and 4, respectively, for all other treatments). No serious systemic toxicity was observed. Histology of the liver showed no serious damage.

CONCLUSION

Hi + M-IHP has synergistic antitumor effects without any increase in regional or systemic toxicity.

Bio-chemotherapeutic strategies and the (dis) utility of hypoxic perfusion of liver, abdomen and pelvis using balloon catheter techniques

AIMS

To review the development and current status of balloon catheter mediated hypoxic perfusion of abdomen, pelvis and liver for treatment of locally advanced malignancies. Within this context we focus on the addition of tumour necrosis factor-alpha (TNF) to these minimal invasive perfusion procedures.

METHODS

A literature search on these topics was carried out in PubMed for indexed articles and in all issues of Regional Cancer Treatment. The findings were related to our own experiences.

RESULTS

Hypoxic abdominal (HAP) and hypoxic pelvic perfusion (HPP) using balloon catheters, are currently applied modalities for treatment of a wide variety of abdominal and pelvic tumours, yet scientific validation of these procedures is poor. Following the results of several Phase I-II trials, both treatments are associated with severe systemic toxicity, significant morbidity and even mortality. The degree of systemic leakage associated with these procedures prohibits addition of TNF. For leakage free liver perfusion surgery is still required, as with current balloon catheter techniques it is not possible to perform leakage free isolated hypoxic hepatic perfusion (IHHP), using either orthograde or retrograde hepatic flow. Experimental and clinical observations suggest that within any perfusion setting, the utilization of TNF is only indicated for treatment of highly vascularised tumours and not for treatment of colorectal tumours.

CONCLUSION

Balloon catheter technology in its present form does not provide adequate leakage control in any of these settings and is therefore associated with considerable toxicity. It is associated with poor response rates and cannot be considered in any setting as a standard of care.

Liposomal Cytokines in the Treatment of Infectious Diseases and Cancer

Despite of the demonstrated activity of cytokines in vitro, their use in the clinical setting is often disappointing. Cytokine-related toxicity seriously limits optimal use in vivo. In addition, rapid degradation and excretion, neutralization and binding to receptors, or metabolization of the molecule results in a short half-life in serum when injected intravenously. As the dose-response curve of cytokines is relatively steep, outcome greatly benefits from improved delivery and bioavailability. One way to improve the pharmacokinetics of cytokines after systemic application is encapsulation in liposomes. An advantage of liposomes is that the encapsulated drug is protected from (rapid) degradation and excretion, and it eliminates the binding to neutralizing antibodies or (soluble) receptors. Moreover, liposomes can be tailored in such a way that they exhibit favorable pharmacokinetics, i.e., increased serum half-life and improved targeting to tissues or cells of interest. In this chapter, the use of liposomal cytokines in the treatment of cancer and infectious disease is discussed.

Isolated hepatic perfusion for the treatment of colorectal metastases confined to the liver: recent trends and perspectives

Isolated hepatic perfusion (IHP) involves a method of complete vascular isolation of the liver to allow treatment of liver tumours with toxic systemic doses. The recent clinical studies mainly employed IHP with melphalan with or without tumour necrosis factor-alpha (TNF-alpha) and mild hyperthermia. The results of these studies show that high response rates and high survival rates can be achieved by IHP. In this article, the current status, recent developments and future perspectives of IHP are discussed.

Isolated hypoxic hepatic perfusion with orthograde or retrograde flow in patients with irresectable liver metastases using percutaneous balloon catheter techniques: a phase I and II study

BACKGROUND

Isolated hepatic perfusion for irresectable metastases confined to the liver has reported response rates of 50% to 75%. Magnitude, costs, and nonrepeatability of the procedure are its major drawbacks. We developed a less invasive, less costly, and potentially repeatable balloon catheter-mediated isolated hypoxic hepatic perfusion (IHHP) technique.

METHODS

In this phase I and II study, 18 consecutive patients with irresectable colorectal or ocular melanoma hepatic metastases were included. Two different perfusion methods were used, both with inflow via the hepatic artery, using melphalan 1 mg/kg. In the first eight patients, the portal vein was occluded, and outflow was via the hepatic veins into an intracaval double-balloon catheter. This orthograde IHHP had on average 56% leakage. In next 10 patients, we performed a retrograde outflow IHHP with a triple balloon blocking outflow into the caval vein and allowing outflow via the portal vein. The retrograde IHHP still had 35% leakage on average.

RESULTS

Although local drug concentrations were high with retrograde IHHP, systemic toxicity was still moderate to severe. Partial responses were seen in 12% and stable disease in 81% of patients. The median time to local progression was 4.8 months.

CONCLUSIONS

We have abandoned occlusion balloon methodology for IHHP because it failed to obtain leakage control. We are presently conducting a study using a simplified surgical retrograde IHHP method, in which leakage is fully controlled, which translates into high response rates.

True versus mild hyperthermia during isolated hepatic perfusion: effects on melphalan pharmacokinetics and liver function

Hyperthermic antiblastic isolated hepatic perfusion (IHP) with melphalan has been recently proposed as an alternative therapeutic option for patients with unresectable liver tumors. Although melphalan-heat antiblastic synergism is at a maximum at temperatures higher than 41 degrees C, IHP has so far been performed in humans at lower temperatures. In this experimental work, we compared IHP under mild versus true hyperthermic conditions in terms of drug pharmacokinetics and liver function. Ten pigs were submitted to IHP with melphalan 1.5 mg/kg at a mean temperature of 40 degrees C (group A, n = 5) or 42 degrees C (group B, n = 5). After a 60-minute perfusion, a 15-minute washout was performed. Perfusate-to-plasma leakage was monitored using scintigraphy. Throughout perfusion, samples from the systemic blood, perfusate, and liver parenchyma were obtained to measure melphalan concentrations. Liver function was assessed using standard blood tests and the indocyanine green-based test. No deaths related to the IHP procedure were recorded. All animals had transient liver function impairment, with all liver function test results returning to normal within the observation period. At histologic examination, liver damage was similar under both hyperthermic conditions. Melphalan levels in the perfusate were not significantly different in the two study groups (the mean perfusate/plasma area under the curve from 0 to 60 minutes ratios were 463 and 501, respectively). These results correlated well with those obtained using the scintigraphic method. Liver drug concentrations remained unchanged after true hyperthermia IHP. Under true hyperthermic conditions, neither an increase in liver parenchyma toxicity nor changes in melphalan pharmacokinetics were observed. These findings support the use of true hyperthermia in the clinical setting to exploit fully the antitumor synergism between melphalan and heat.

Isolated hepatic perfusion: experimental evidence and clinical utility

Many patients with tumors confined to the liver are not amenable for surgical resection, and an increasing number of these patients are treated by local ablation methods. Isolated hepatic perfusion is another treatment option especially suitable for patients with multiple or bulky primary or metastatic tumors. and can mediate clinical regression of advanced liver metastases. Experience with IHP is still limited to a few centers in the world because of its technical difficulties, surgery-related morbidity, and unproven efficacy. IHP remains an experimental modality restricted to specialized units dedicated to treating this difficult group of patients. Experimental animal IHP models have led us to explore new ways of improving efficacy, reducing technical difficulties, and minimizing regional and systemic toxicity. Future research should be directed to the identification of suitable biological or chemotherapeutic agents, defining clinical indications, and development of technical modifications to make it more generally applicable.

Isolated hepatic perfusion with high-dose melphalan for the treatment of colorectal metastasis confined to the liver

BACKGROUND

Isolated hepatic perfusion (IHP) involves complete vascular isolation of the liver to allow treatment with doses that would be toxic if delivered systemically. A phase II study of IHP in patients with colorectal metastases confined to the liver was performed.

METHODS

Seventy-three patients with irresectable colorectal metastases underwent IHP with high-dose melphalan (200 mg) for 1 h. Toxicity was graded according to the National Cancer Institute Common Toxicity Criteria and tumour response was assessed according to World Health Organization criteria.

RESULTS

Seventy-one patients were perfused according to the protocol. Four patients died within 30 days after IHP, resulting in an operative mortality rate of 5.6 per cent. Sixteen patients (22.5 per cent) experienced grade 3-4 hepatotoxicity 1 week after IHP, which was transient and resolved within 3 months in all patients. The tumour response rate (complete or partial remission) was 59 per cent. Median time to progression was 7.7 (range 2.3-31.4) months. Overall median survival after IHP was 28.8 months with a 3-year survival rate of 37 per cent.

CONCLUSION

IHP for irresectable colorectal metastases confined to the liver resulted in good response rates and long-term survival in a selected group of patients.

An experimental minimally invasive perfusion technique for the treatment of liver metastases

AIM

Isolated hepatic perfusion (IHP) is an invasive, technically difficult, non-repeatable and demanding operation. In this study we report the development of a less invasive alternative for the surgical IHP in a pig model.

METHODS

Our technique was tested in 8 Yorkshire pigs (60 kg). The liver was isolated from the systemic circuit using minimally invasive techniques: an occlusion stent-graft and balloon catheters, with reversal of the blood flow through the liver during IHP.

RESULTS

Tests with varying pressures applied at the PV revealed a clear relation between the suction pressure at the outflow site (PV), intrahepatic pressure and systemic leakage of 99mTc. A leakage-free IHP could be obtained in seven separate experiments.

CONCLUSION

Isolated hepatic perfusion using minimally invasive techniques is feasible in pigs when the intrahepatic pressure is controlled. This technique has yet to be tested in patients.

Solid tumor therapy: manipulation of the vasculature with TNF

Drug delivery to solid tumors is one of the most challenging aspects in cancer therapy. Whereas agents seem promising in the test tube, clinical trials often fail due to unfavorable pharmacokinetics, poor delivery, low local concentrations, and limited accumulation in the target cell. A major step forwards in the treatment of solid tumors is the recognition of the tumor-associated vasculature as an important target for therapy. Inhibition of tumor vascular development has a direct effect on the growth and progression of the tumor. Destruction of an existing vasculature also directly inflicts serious damage to the tumor cell. Moreover, the tumor vascular bed can be manipulated facilitating enhanced permissiveness of the tumor for administered chemotherapeutics. In this review, we focus on the use of tumor necrosis factor alpha (TNF) in local and systemic therapy in conjunction with chemotherapy. In these settings TNF demonstrates potent and selective activity on the tumor vascular bed, which strongly improves tumor response.

Isolated liver perfusion for non-resectable liver tumours: a review

Many treatments have been proposed for non-resectable primary or secondary hepatic cancer but the results have generally been disappointing. Isolated Hepatic Perfusion (IHP) was first attempted four decades ago but it gained acceptance only recently, after spectacular tumour responses were obtained by isolated limb perfusion with melphalan and tumour necrosis factor (TNF) for melanomas and sarcomas. Surgical isolation of the liver is a technically demanding operation that allows the safe administration of high doses of chemotherapeutics and TNF. Percutaneous techniques using balloon occlusion catheters are simpler but result in higher leakage rates from the perfusion circuit into the systemic circulation. Several phase I-II trials indicate that IHP can yield high tumour response rates, even when there is resistance to systemic chemotherapy. However, no significant advantage in overall survival has been demonstrated so far. IHP offers unique pharmacokinetic advantages for locoregional chemotherapy and biotherapy. It might also allow gene therapy with limited systemic exposure and toxicity. At present, IHP nevertheless remains an experimental treatment modality which should therefore be used in controlled trials only.

Raltitrexed treatment promotes systemic inflammatory reaction in patients with colorectal carcinoma

We studied longitudinally inflammatory reactions and serum C-reactive protein (S-CRP) levels in 52 colorectal cancer patients treated with a median of six 3-weekly cycles of raltitrexed 1.5-3.0 mg m(-2) combined with oral carmofur (1-hexylcarbomoyl-5-fluorouracil) 300-400 mg m(-2) on cycle days 2-14. Thirty-nine (75%) of these patients had fever on days 2 to 9 after receiving raltitrexed, 49 (94%) had fatigue Gr. > or = 1, and 49 (94%) elevated S-CRP without a documented infection. The systemic inflammatory composite score (consists of body temperature, fatigue, S-CRP, interleukin-6 (S-IL-6), S-IL-8, and tumour necrosis factor-alpha (S-TNF alpha) levels) was calculated in a cross-sectional one-cycle study involving 60 colorectal cancer patients treated with single-agent raltitrexed, raltitrexed and carmofur, or 5-fluorouracil-based chemotherapy (n=20 in each group). The median S-CRP, S-IL-6, and S-TNF alpha levels were higher 7 days after giving raltitrexed (57 vs 23 mg l(-1), 64 vs 10 ng l(-1), and 11 vs 10 ng l(-1), respectively) or raltitrexed+carmofur (142 vs 10 mg l(-1), 64 vs 10 ng l(-1), and 16 vs 9 ng l(-1), respectively) than at baseline (P<0.01 for each comparison), but not when 5-fluorouracil-based regimens were administered. These findings suggest that colorectal cancer patients treated with raltitrexed may develop drug-related systemic inflammation, which may be difficult to discriminate from infection.

Transarterial perfusion of liver metastases

Progressive growth of unresectable metastatic or primary malignancies confined to the liver is a significant clinical problem. Approximately 25% of patients with colorectal cancer will develop metastatic disease exclusively or largely confined to liver, the vast majority of which are not amenable to surgical resection. Despite aggressive systemic or regional chemotherapy, survival is only 12 to 18 months. More than 80% of patients with ocular melanoma develop liver metastases as the first site of recurrent disease, and death from hepatic disease progression typically occurs 2 to 7 months after diagnosis. In addition, the liver is also the preferred site of metastatic disease for gastrointestinal or pancreatic neuroendocrine tumors. A number of physiological and anatomic features of the liver make it an ideal organ for regionally directed therapy to allow dose intensification to the cancer-burdened area while reducing or eliminating unnecessary systemic toxicity. To that end, complete vascular isolation and perfusion of the liver using a recirculating extracorporeal circuit, also called isolated hepatic perfusion (IHP), has been under clinical evaluation at our institution and others. In this article, we review the current results with IHP and its potential utility in the treatment of patients with unresectable hepatic malignancies.

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.

Prerequisites for effective adenovirus mediated gene therapy of colorectal liver metastases in the rat using an intracellular neutralizing antibody fragment to p21-Ras

Ras mutations are present in 40-50% of colorectal cancers. Inactivating this oncogene may therefore reduce proliferation capacity. In order to target ras we studied the transduction efficacy and anti tumour activity of an adenoviral vector expressing an intracellular, neutralizing single chain antibody to p21-ras (Y28). In in vitro studies transfection levels of the K-ras mutated rat colon carcinoma cell line CC531 were studied using the LacZ marker gene. In our in vivo liver metastases model different routes of administration were evaluated to determine which regimen resulted in the best transfection levels and tumour responses: intravenous injection, intratumoural injection, isolated liver perfusion, or hepatic artery infusion. CC531 cells are readily transfected in vitro, resulting in significant inhibition of tumour cell proliferation by the Y28 construct. Intravenous injection did not result in any measurable transfection. Intratumoural injection resulted only in the transfection of tumour cells along the needle track. IHP as well as single HAI achieved low transfection levels of tumour tissue. Expression of Y28 was demonstrated in tumours after IT injection, HAI and IHP. Whereas, repeated HAI's clearly achieved expression in and around tumour associated vessels. Only five times repeated HAI's with Y28 resulted in a tumour response: in all animals tumour growth was inhibited, and in three rats out of eight a complete regression of the liver tumours was observed.

Status of hyperthermia in the treatment of advanced liver cancer

The vast majority of patients with malignant liver tumors have inoperable disease. These patients must rely on chemotherapy, radiotherapy, and various locoregional treatments. Although these treatments have demonstrated encouraging response rates, symptom palliation and occasional down staging of tumors, their impact on survival is minor. As a result there has been renewed interest in hyperthermia as a treatment option. This study reviews the current modalities of hyperthermia in terms of clinical results, side effects, limitations, and therapeutic standing.

Current status of isolated hepatic perfusion with or without tumor necrosis factor for the treatment of unresectable cancers confined to liver

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. A number of regional treatment strategies including infusional chemotherapy and local ablative therapy are under clinical development and attest to the difficulty in adequately treating this condition. 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 gained widespread application. In light of the remarkable 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 unresectable liver cancers. IHP with TNF and melphalan can result in significant regression of advanced refractory cancers confined to the liver and, with additional clinical development, will most likely be a more routinely considered option for patients with this condition.

Isolated hepatic perfusion for unresectable hepatic metastases from colorectal cancer

BACKGROUND

Unresectable colorectal liver metastases are a significant clinical problem. Isolated hepatic perfusion (IHP) is a regional treatment technique that delivers high dose chemotherapy, biologic agents, and hyperthermia via a completely isolated vascular recirculating perfusion circuit as a means of regionally treating liver tumors. This study presents our results of IHP with tumor necrosis factor (TNF) plus melphalan or IHP with melphalan alone followed by infusional floxuridine (FUDR) and leucovorin in patients with advanced or refractory unresectable hepatic colorectal metastases.

METHODS

Fifty-one patients with unresectable colorectal hepatic metastases underwent a 60-minute IHP with 1.5 mg/kg melphalan and hyperthermia (39 degrees C to 40 degrees C). Thirty-two patients received IHP with 1 mg TNF with melphalan and 19 patients had IHP with melphalan alone followed by monthly hepatic intra-arterial infusional (HAI) FUDR (0.2 mg/kg/day) and leucovorin (15 mg/M(2)/day) for 14 days monthly for up to 12 months. Twenty-six patients failed 1 or more previous treatment regimens for established hepatic metastases and 27 had greater than 25% hepatic replacement (PHR) by tumor. Patients were monitored for response, toxicity, and survival.

RESULTS

There was 1 perioperative death (2%), and only 2 patients (4%) had measurable perfusate leak during IHP (both less than 4%). In the 32 patients treated with IHP alone there were no detectable systemic TNF or melphalan levels during perfusion. The overall objective radiographic response rate (all partial [PR]) was 76% (38 of 50 assessable patients) with a median duration of 10.5 months (range, 2 to 21 months). Twenty-four of 31 patients (77%) had a PR after IHP alone and 14 of 19 (74%) after IHP with postperfusion HAI. Median duration of response was 8.5 months after IHP alone and 14.5 months after IHP and HAI; median survival was 16 and 27 months, respectively. There were 18 PRs in 26 patients (69%) whose prior therapy had failed and 18 PRs in 27 patients (67%) with PHR of 25 or greater.

CONCLUSIONS

IHP can be performed with acceptably low morbidity and has significant antitumor activity in patients with unresectable hepatic metastases from colorectal cancer including those with refractory disease or PHR of 25 or greater. HAI appears to prolong the duration of response after IHP, and this combined treatment strategy deserves additional clinical evaluation as a therapeutic modality in this setting.

Technique and results of hyperthermic isolated hepatic perfusion with tumor necrosis factor and melphalan for the treatment of unresectable hepatic malignancies

BACKGROUND

For a variety of histologies, the liver represents the only or the dominant site of metastatic disease. Regional treatment of the liver has the theoretic advantage of maximizing drug delivery while minimizing systemic toxicity. This article describes the technique of isolated hepatic perfusion using tumor necrosis factor and melphalan under conditions of moderate hyperthermia for the treatment of unresectable liver tumors.

STUDY DESIGN

Fifty patients with biopsy-proved unresectable primary or metastatic cancer to the liver were treated. Isolated hepatic perfusion was performed for 60 minutes under conditions of moderate hyperthermia during a laparotomy with inflow through the gastroduodenal artery and outflow through an isolated segment of inferior vena cava. During isolated hepatic perfusion portal and infrahepatic blood flow were shunted externally by a centrifugal pump to the axillary vein. Complete vascular isolation was confirmed intraoperatively using a continuous 131I-labeled serum albumin leak monitoring system. Operative and perfusion parameters were recorded.

RESULTS

By using a standard operative technique to achieve complete vascular isolation of the liver during perfusion, there was no leak ofperfusate detected in 48 of 50 patients as determined by the continuous leak monitoring system and absence of detectable systemic tumor necrosis factor levels. Operating time, transfusion requirements, and blood loss were within the range expected for a major operative procedure. Stable hemodynamic and perfusion parameters were achieved consistently and all patients successfully completed the 60-minute perfusion. Two patients (4%) died as a result of treatment and significant tumor regression was observed in 75%.

CONCLUSIONS

Isolated hepatic perfusion is a technique that can be used to deliver high doses of chemotherapy or biologic therapy regionally and without systemic exposure. By using a standard operative technique, continuous intraoperative leak monitoring, and an external veno-veno bypass circuit, this procedure can be done safely and with acceptable morbidity and mortality. This article demonstrates that sustained and complete vascular isolation of the liver can be achieved and indicates further study is warranted to better define the role of isolated hepatic perfusion in the treatment of unresectable liver tumors.

Tumor necrosis factor-alpha augments tumor effects in isolated hepatic perfusion with melphalan in a rat sarcoma model

Isolated hepatic perfusion (IHP) is an attractive approach to treating nonresectable liver tumors, because the effects of systemic chemotherapy are poor and its application is hampered by severe general toxicity. In clinical and experimental settings, the efficacy of isolated limb perfusion (ILP) with tumor necrosis factor-alpha (TNF alpha) in combination with melphalan to treat melanoma in transit and soft-tissue sarcoma has been well established. In an ILP model in rats, the authors previously observed synergistic anti-tumor effects of TNF and melphalan on BN 175 soft-tissue sarcoma extremity tumors. The aim of the current study was to determine whether similar synergy in anti-tumor effects could be achieved by treating experimental BN 175 soft-tissue sarcoma liver tumors by IHP using these agents. The authors found that IHP with TNF and melphalan resulted in a dramatic increase in regional concentrations of perfused agents with virtually no concomitant systemic leakage. Isolated hepatic perfusion with only carrier solution resulted in a significantly diminished growth rate of BN 175 liver tumors compared with the growth rate of tumors in nonperfused rats. Perfusion with melphalan alone resulted in minimal anti-tumor effects. Perfusion with only TNF had a slight growth-stimulatory effect on the BN 175 liver tumors, but no negative effects on tumor growth were observed. When TNF was added to melphalan, a dramatic anti-tumor effect was observed. Thus, as in the rat ILP setting, the anti-tumor effect is augmented when TNF is added to IHP with melphalan to treat BN 175 soft-tissue sarcoma tumor-bearing rats. Strikingly, the tumor response was potentiated at relatively low concentrations of TNF compared with concentrations that elicited synergy with melphalan in ILP.

Immunology and immunotherapy of human cancer: present concepts and clinical developments

Immunotherapy of cancer is entering into a new phase of active investigation both at the pre-clinical and clinical level. This is due to the exciting developments in basic immunology and tumour biology that have allowed a tremendous increase in our understanding of mechanisms of interactions between the immune system and tumour cells. This review briefly summarizes the state of the art in basic tumour immunology before discussing the clinical applications of the new concepts in the clinical setting. Clinical approaches are diverse but can now be based on strong scientific rationales. The analysis of the available clinical results suggests that, despite some disappointments, there is room for optimism that both active immunotherapy (vaccination) and adoptive immunotherapy may soon become part of the therapeutic arsenal to combat cancer in a more efficient way.

Cancer surgery: the last 25 years

Surgery is, and always has been, the main treatment modality of solid tumours. For a long period, it consisted of a number of surgical procedures dictated by basic oncologic principles, most of which are still adhered to. Over the last few decades, increased understanding of the disease, new or improved diagnostic facilities, novel and perfected adjuvant treatments, improved surgical techniques and daring challenges to established dogmas have all contributed to the development of surgical oncology. The heritage from the past came under close scrutiny, and the fruits of basic and clinical science were added to an ever expanding body of knowledge. It is impossible to review all developments in surgical oncology of the last 25 years in one comprehensive paper. Therefore we have restricted ourselves to those items that appear most representative for the changes that have taken place, and those diseases that have the greatest numerical impact.

Prerequisites for effective isolated limb perfusion using tumour necrosis factor alpha and melphalan in rats

An isolated limb perfusion (ILP) model using soft tissue sarcoma-bearing rats was used to study prerequisites for an effective ILP, such as oxygenation of the perfusate, temperature of the limb, duration of the perfusion and concentration of tumour necrosis factor (TNF). Combination of 50 microg TNF and 40 microg melphalan demonstrated synergistic activity leading to a partial and complete response rate of 71%. In comparison to oxygenated ILP, hypoxia was shown to enhance anti-tumour activity of melphalan alone and TNF alone but not of their combined use. Shorter perfusion times decreased anti-tumour responses. At a temperature of 24-26 degrees C, anti-tumour effects were lost, whereas temperatures of 38-39 degrees C or 42-43 degrees C resulted in higher response rates. However, at 42-43 degrees C, local toxicity impaired limb function dramatically. Synergy between TNF and melphalan was lost at a dose of TNF below 10 microg in 5 ml perfusate. We conclude that the combination of TNF and melphalan has strong synergistic anti-tumour effects in our model, just as in the clinical setting. Hypoxia enhanced activity of melphalan and TNF alone but not the efficacy of their combined use. For an optimal ILP, minimal perfusion time of 30 min and minimal temperature of 38 degrees C was mandatory. Moreover, the dose of TNF could be lowered to 10 microg per 5 ml perfusate, which might allow the use of TNF in less leakage-free or less inert perfusion settings.

Isolated hypoxic hepatic perfusion with tumor necrosis factor-alpha, melphalan, and mitomycin C using balloon catheter techniques: a pharmacokinetic study in pigs

OBJECTIVE

To validate the methodology of isolated hypoxic hepatic perfusion (IHHP) using balloon catheter techniques and to gain insight into the distribution of tumor necrosis factor-alpha (TNF), melphalan, and mitomycin C (MMC) through the regional and systemic blood compartments when applying these techniques.

SUMMARY BACKGROUND DATA

There is no standard treatment for unresectable liver tumors. Clinical results of isolated limb perfusion with high-dose TNF and melphalan for the treatment of melanoma and sarcoma have been promising, and attempts have been made to extrapolate this success to the isolated liver perfusion setting. The magnitude and toxicity of the surgical procedure, however, have limited clinical applicability.

METHODS

Pigs underwent IHHP with TNF, melphalan, and MMC using balloon catheters or served as controls, receiving equivalent dosages of these agents intravenously. After a 20-minute perfusion, a washout procedure was performed for 10 minutes, after which isolation was terminated. Throughout the procedure and afterward, blood samples were obtained from the hepatic and systemic blood compartments and concentrations of perfused agents were determined.

RESULTS

During perfusion, locoregional plasma drug concentrations were 20- to 40-fold higher than systemic concentrations. Compared with systemic concentrations after intravenous administration, regional concentrations during IHHP were up to 10-fold higher. Regional MMC and melphalan levels steadily declined during perfusion, indicating rapid uptake by the liver tissue; minimal systemic concentrations indicated virtually no leakage to the systemic blood compartment. During isolation, concentrations of TNF in the perfusate declined only slightly, indicating limited uptake by the liver tissue; no leakage of TNF to the systemic circulation was observed. After termination of isolation, systemic TNF levels showed only a minor transient elevation, indicating that the washout procedure at the end of the perfusions was fully effective.

CONCLUSIONS

Complete isolation of the hepatic vascular bed can be accomplished when performing IHHP using this balloon catheter technique. Thus, as in extremities, an ideal leakage-free perfusion of the liver can now be performed, and repeated, without major surgery. The effective washout allows the addition of TNF in this setting.