INTRASPLENIC IMMUNOSTIMULATION IN MALIGNANCIES FACT OR FICTION - PRESENT AND FUTURE

BACKGROUND/AIMS: The clinical application of intrasplenic immunostimul ation with IL-2 in a group of patients suffering from metastatic renal carcinoma, melanoma, recurrent rectal carcinoma, lung carcinoma and g astric carcinoma are discussed in terms of clinical applicability, eff ectiveness and survival. METHODOLOGY: From May 1996 to February 1998, 45 patients with advanced malignancies were admitted to Athens Medical Center for intrasplenic immunostimulation. Transplenic immunostimulat ion was carried out via a subcutaneously implanted port. The injected therapy included IL-2 (Proleukin) 1 ml 18x10(6) suspended in 1.5 ml of lipiodol and 0.5 ml of urografin. In conjunction gamma-INF (Immukin) 0.5 ml 100 meg, was administered. RESULTS: Patients included in this s tudy have completed their treatment;, or are still undergoing maintena nce treatment. The duration of the CR was between 11 and 16 months, an d for PR was between 10-14 months. For melanoma patients (n=9), 3 pati ents with PD died 9,10 and 12 months after initial treatment began. Th e remaining patients (n=6) are alive with a mean survival rate of 16 m onths. Of those patients, 4 have been classified as complete responder s, being completely free of disease at this time. The number of CR for patients with lung, renal and recurrent rectal cancer was achieved as a result of the continuing maintenance treatment. Twenty-two patients remain alive and 23 patients have died. From those alive (n=22), 10 p atients are complete responders and free of disease, 10 are partial re sponders with controlled disease and 2 remain with standard disease. F or those surviving patients with lung cancer, the mean survival time i s 14 months. Patients with recurrent rectal cancer and renal cancer we re shown to have a mean survival time of 15 and 13 months, respectivel y. CONCLUSION: The safety, effectiveness and feasibility of long-lasti ng administration of high dosages of IL-2 are documented from the data of this study. Intrasplenic immunostimulation utilizing lipiodol-urog rafin emulsion as a carrier, offers new possibilities for the safe adm inistration of long lasting high dosages of IL-2 and gamma-INF. Furthe r studies are warranted, to further elucidate the results of this phen omenon.