Long-term survival in patients with metastatic renal cell carcinoma treated with continuous intravenous infusion of recombinant interleukin-2: The experience of a single institution

Aim and background: Metastatic renal cell carcinoma is one of the few tumors for which a clear benefit of immunotherapy has been demonstrated. The aim of this study was to evaluate the long-term survival of patients with metastatic renal cell carcinoma, along with response rate and other prognostic and predictive factors. Patients and methods: Between July 1989 and May 1995, 56 patients with metastatic renal cell carcinoma were treated in a single institution with high-dose recombinant interleukin-2 in continuous infusion. Survival was measured by the Kaplan and Meier method. Prognostic factors were assessed by univariate and multivariate analyses of survival (Cox proportional hazard ratio model). Results: Of 56 patients, 15 had objective responses (26.8%), 16 stable disease (28.6%), 18 disease progressions (32.1%), and 7 (12.5%) were not valuable for response. Median overall survival was 20 months, and probability of 2- and 5-year survival was 41% and 21%, respectively. At multivariate analysis, the increased risk of death for: performance status greater than or equal to2 vs 0 (HR=6.20), stable disease (HR=1.87), disease progression (HR=10.61) vs partial or complete remission, and for hypotension and oliguria toxicity, G3 + G4 vs G1 + G2 (HR = 2.19). Conclusions: Our study confirms the activity of IL-2 based immunotherapy in renal cell carcinoma. Moreover, ECOG performance status, clinical response, hypotension and oliguria toxicity resulted as independent survival prognostic factors.