Metastatic renal cell carcinoma: long-term survival after therapy with high-dose continuous-infusion interleukin-2

This article undertakes to define the response rate, long-term survival, and toxicity in patients with metastatic renal cell carcinoma (MRCC) treated with high-dose continuous intravenous infusion (CIV) recombinant interleukin-2 (rIL-2) with or without lymphokine-activated killer (LAK) cells.

One hundred twenty-three consecutive patients received CIV rIL-2 (18-22 MIU/m2/day on days 1-5, and 6-8 MIU/m2/day on days 10-19) on one of five sequential protocols at the University of Washington between 1988 and 1995. The first 76 patients received LAK cells. The median age was 55 years (range, 32-76 years), and 71% had undergone prior nephrectomy.

Nine patients achieved a complete response (7.3%) and 14 patients achieved a partial response (11.4%) for an overall response rate of 19% (95% confidence interval, 12%-26%). The median survival was 19 months, and the 5-year survival was 20%. Seven of nine complete responders (78%) remain in continuing complete response at 43+ to 109+ months. Intensive care unit and vasopressor support were required in 42% and 23% of patients, respectively, who received rIL-2 + LAK cells, and in 18% and 4% of those who received rIL-2 alone. There was one treatment-related death.

We report the largest single-institution experience and the longest survival for patients with MRCC treated with CIV rIL-2. The administration of rIL-2 by CIV is associated with less frequent intensive care unit and vasopressor support than with high-dose intravenous bolus regimens, and hence may enhance the therapeutic index in patients with MRCC.