[Immunotherapy with low-dose subcutaneous interleukin-2 in metastatic renal carcinoma]

The intravenous injection of interleukin-2 (IL-2) has appeared to induce tumor regression in metastatic renal cell carcinoma (RCC). IL-2 given subcutaneously has also appeared to be effective when it is administered in association with interferon-alpha (INF), but with a lower toxicity in comparison to the intravenous route of administration. The present study was carried out to evaluate the efficacy of a subcutaneous immunotherapy with IL-2 alone in metastatic RCC. The study included 30 consecutive patients affected by metastatic RCC, 14 of whom had been pretreated with INF plus vinblastine, while the other 16 patients received IL-2 as a first line therapy of their metastatic disease. IL-2 was given subcutaneously at a dose of 3 million IU twice/day for 5 days/week for 6 consecutive weeks, corresponding to one cycle of immunotherapy. No complete response was obtained. A partial response (PR) was achieved in 10/30 (33%) patients (median duration: 7 months, range 5-25), without any significant difference between patients pretreated with IFN and nonpretreated patients (4/14 vs 6/16). Response rate was significantly higher in nephrectomized patients than in those who did not undergo nephrectomy (10/25 vs 0/5; P < 0.01). Moreover, response rate was significantly higher in patients with performance status (PS) greater than 40% than in those with PS lower than 40% (10/23 vs 0/7; P < 0.01). A stable disease (SD) was obtained in 12/30 (40%) patients (median duration 5 months, range 3-13), while the remaining 8/30 (27%) progressed. The increase in lymphocyte and eosinophil mean number was significantly higher in patients with PR or SD than in the progressed ones.(ABSTRACT TRUNCATED AT 250 WORDS)