IL-2 perfusion to the liver augments the hepatic extraction rate of accompanying anticancer drugs

Transarterial chemoembolization alone and in combination with other therapies: a comparative study in an animal HCC model

The purpose of this study is to compare transarterial chemoembolization (TACE) alone and in combination with other therapies in an animal model. Subcapsular implantation of a solid Morris hepatoma 3924A in the liver was carried out in 50 male ACI rats (day 0). Tumor volume (V1) was measured by MRI (day 13). After laparotomy and retrograde placement of a catheter into the gastroduodenal artery (day 14), the following protocols of the interventional procedure were applied: TACE (mitomycin C + lipiodol) + immunotherapy (group A: TNFalpha + IL-2, group B: OK-432 + IL-2); TACE + antiangiogenesis therapy (group C: TNP-470, group D: endostatin); TACE alone in group E (control group). Tumor volume (V2) was assessed by MRI and the mean ratio of x (V2/V1) was calculated. Data were analyzed using Dunnett's t test (comparing therapeutic groups with the control group) and the Student-Newman-Keuls test (comparing significant therapeutic groups). Multivariate analysis showed a significant reduction in the tumor growth rate (P<0.05) in groups B (x=6.53) and C (x=4.01) compared to the mean ratio of the control group E (x=9.14). Significant results were observed in group C (P<0.05) in comparison with the other therapeutic groups. TACE combined with immunotherapy (OK-432) and antiangiogenesis therapy (TNP-470) retards tumor growth compared with TACE alone in an HCC animal model.

Locoregional immuno(bio)therapy for liver metastases

Despite advances in locoregional chemotherapy, treatment of metastatic liver tumors remains a challenge. Since the liver is the largest organ of the reticuloendothelial system, locoregional immunotherapy would be a reasonable approach for the management of hepatic metastases. Indeed, various immunological approaches have been explored. Regional infusion of cytokines such as interleukin 2 (IL-2) or tumor necrosis factor-alpha (TNF-alpha) through the hepatic artery or the portal vein has been combined with chemotherapy and demonstrated to be better than chemotherapy alone. Locoregional adaptive immunotherapy (AIT) using lymphokine-activated killer (LAK) cells or tumor-infiltrating lymphocytes (TIL) has also been tried with rather disappointing responses. Addition of immunostimulants such as OK-432 to AIT increased clinical responses. Recently, several new approaches have emerged to improve the outcome of locoregional immunotherapy. Embolization of melanoma metastatic to the liver with a granulocyte-macrophage colony-stimulating factor (GM-CSF)/ethiodized oil emulsion resulted in control of liver metastases, as well as development of significant immune responses in remote extrahepatic metastases. A gene therapy designed to introduce foreign major histocompatibility complex (MHC) molecules in colorectal metastases has proven to be a safe and feasible approach. Larger scale clinical trials are mandatory to define the role of locoregional immunotherapy for metastatic tumors in the liver.

The role of adjuvant therapy after liver resection for colorectal cancer metastases

Intrahepatic recurrence is common after major resection for colorectal cancer (CRC) metastases to the liver. In this review, the available data on different adjuvant therapies from systemic chemotherapy to regional approaches by direct perfusion of chemotherapeutic agents via the hepatic artery and portal vein will be discussed. Intraperitoneal administration of chemotherapy is another form of regional therapy. Novel approaches with immunotherapy and trials of neoadjuvant therapy in association with resection of CRC hepatic metastases have also been reported. The purpose of this review is to outline these various strategies and their role in combination with resection of CRC liver metastases. Although improved hepatic disease-free survival has been demonstrated with some strategies, overall survival is minimally affected and recurrence of metastatic disease at distant sites is still a major problem. Therefore, future directions should incorporate the use of new systemic agents effective against CRC metastases. Identification of subgroups through clinical features, molecular markers, proteins, or specific tumor properties may also help to individualize treatment.

Locoregional immunotherapy in cancer patients: review of clinical studies

Many patients with invasive cancer have a compromised immune system. This immune dysfunction does appear to start at the site of the tumor. Locoregional immunotherapy is given to stimulate the immune system in order to kill tumor cells either indirectly via a specific or a non-specific way or directly via cell transfer therapy. Advantages to give this immunotherapy locoregionally in stead of systemically are a higher concentration of the immunomodulator at the site of the tumor, to attract or activate effector cells, and diminished toxicity. In this review we have summarised the clinical studies using loco-regional immunotherapy in patients with cancer. Only phase I and II studies were performed. Clinical responses were seen. No single locoregional treatment has become a standard therapy. Relatively few investigations were performed to estimate the influence on the locally effector mechanisms or immune dysfunction. In future clinical trials it is essential to get a better insight in these mechanisms.

Longterm effects of hepatic arterial interleukin-2-based immunochemotherapy after potentially curative resection of colorectal liver metastases

BACKGROUND

Our previous study of hepatic arterial infusion of interleukin-2 (IL-2)-based immunochemotherapy demonstrated a high response rate of patients with unresectable liver metastases. In this study, we applied this therapy to the prevention of liver recurrence in patients who underwent potentially curative resection of liver metastases.

STUDY DESIGN

A pilot study was conducted of 18 patients with liver metastases from primary colorectal cancer who underwent potentially curative liver resection followed by adjuvant immunochemotherapy. The regimen consisted of a weekly hepatic arterial infusion of IL-2 (1.4-2.1 X 10(6) U) and 5-fluorouracil (250 mg) and a bolus of mitomycin C (2-4 mg) for 6 months.

RESULTS

Among 18 patients, 14 are still alive with a median postoperative survival of 52 months (as of April 1998). The 5-year overall survival rate was 75%. Although recurrent cancer developed in 6 of the 18 patients, no patients had recurrence in the residual liver. This complete prevention of liver recurrence is believed to have contributed to the high 5-year survival rate (75%) as compared with the survival rate of patients treated with surgery alone (average, 30%-40%) or with several other forms of adjuvant therapy.

CONCLUSIONS

Interleukin-2-based immunochemotherapy is useful in combination with liver resection for the prevention of liver recurrence in colorectal cancer patients with liver metastases. A multicenter randomized trial is recommended.