From 1986 to 1989, 71 patients with advanced renal cell carcinoma were treated at one institution with either the Phase II agent, taxol, or one of several high dose interleukin-2 (IL-2) protocols. As no responses to taxol were seen, that group may represent the natural history of renal cell carcinoma in a Phase II population. The results of treatment with IL-2 were examined against this background. Concurrently, 17 patients received taxol and 14 patients IL-2. An additional 40 patients subsequently received IL-2. Five taxol patients with Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2 were excluded from the comparison as similar patients were ineligible for the IL-2 studies. There were more patients in the IL-2 groups with non-liver/lung metastases and ECOG PS 0 than in the taxol group. Six (43%) of concurrent IL-2 patients responded [complete response (CR) = 14%; partial response (PR) = 29%]. The response rate for all IL-2-treated patients was 22% (CR +/- 7%, PR +/- 15%). The response rate to IL-2 was higher in cases with ECOG PS 0, time to treatment < 12 months, and no prior chemotherapy. The median time to progression for the concurrent IL-2 group was 4.5 months (4.0 months for all IL-2 patients) and 2.5 months for taxol patients. Median survival for concurrent IL-2 patients was 12.5 months (12 months for all IL-2 patients) and 10 months for taxol patients. Durable remissions resulted in a 21% overall survival at 40 months for all IL-2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)