rIL-2 in metastatic soft tissue sarcomas refractory to chemotherapy: response and enhancement of further chemosensitivity.
Chemotherapy (CT) in advanced and metastatic soft tissue sarcoma (STS) has a reported response rate of 17 to 30%, with a median survival of 30 months. Experimental and clinical studies have demonstrated some response with high-dose intravenous recombinant Interleukin-2 (r-IL2). We report a retrospective analysis of twelve patients with metastatic or locally evolutive STS who received high-dose rIL-2 immunotherapy: all patients were pre-treated with CT and were non responsive. All of these patients developed usual severe toxicity. One patient achieved a partial response with rIL-2 with more than 75% regression of lung metastases. All patients received CT post rIL-2 and 2 of them achieved a further response: 1 of them had a complete response (CR), and one had a partial response (PR). These results suggest that rIL-2 has a relatively low efficacy in patients with STS but that some of these patients can be, after rIL-2, responders to CT despite previous resistance.