Interferon alfa-2a in advanced renal cell carcinoma: treatment results and survival in 159 patients with long-term follow-up.

PURPOSE: Three trials were conducted to define the efficacy and toxicity of interferon alfa-2a in the treatment of metastatic renal cell cancer. Univariate and multivariate analyses were performed to identify prognostic factors for survival. PATIENTS AND METHODS: Prospectively, 159 patients were treated with interferon alfa-2a. In the first trial, 42 patients received 50 x 10(6) U/m2 intramuscularly three times per week. In the second trial, 64 patients received gradually escalating doses of interferon alfa-2a from 3 to 36 x 10(6) U subcutaneously administered daily. The third trial was randomized; 25 patients received daily interferon alfa-2a alone and 28 were treated with daily interferon alfa-2a and 0.15 mg/kg vinblastine every 3 weeks. RESULTS: The overall response proportion was 10% (two complete and 14 partial responses). The median response duration was 12.2 months. The median survival duration was 11.4 months, with 3% of patients alive at 5 or more years. A univariate statistical analysis showed that a Karnofsky performance status > or = 80, prior nephrectomy, and interval from diagnosis to treatment of longer than 365 days were significant prognostic factors for survival. In a multivariate analysis, only prior nephrectomy and Karnofsky performance status > or = 80 were shown to be independent predictors of survival. CONCLUSION: Interferon alfa-2a had minimal antitumor activity in patients with advanced renal cell carcinoma and long-term survival was achieved in a small proportion of patients. The need for continued investigation and the identification of more effective therapy for advanced renal cell carcinoma is evident from the poor overall survival rate observed in these 159 patients. The investigation of new agents and of interferon alfa-2a in combination with other agents remains a priority.