[A case of multiple lung metastases and cervical lymph node metastasis of renal cell carcinoma failing to respond to interferon-alpha (IFN-alpha) but markedly responding to interleukin-2 (IL-2)].

A 59-year-old man was admitted to our hospital with a left renal mass. A tumor was removed by radical nephrectomy and histological examination revealed renal cell carcinoma (pT2 N0 V1a). Two years later, CT scan showed multiple lung metastases. Despite treatment with recombinant IFN-alpha 2b, 5-FU, and MMC, the disease showed slow progression. About three years after the start of combination therapy, cervical lymph node metastasis appeared. Administration of interleukin-2 (IL-2) was attempted. Intravenous IL-2 therapy was started at a low daily dose of 35 x 10(4) JRU, and the daily dose was increased to 140 x 10(4) JRU. Because of side effect, the dose was subsequently decreased to 70 x 10(4) JRU three times per week. After 31 weeks of IL-2 therapy, his multiple lung metastases and cervical lymph node metastasis disappeared. The patient's natural killer cell (NK) activity and Lymphokine activated killer cell (LAK) activity were low before IL-2 therapy, but both NK activity and LAK activity showed a marked increase after IL-2 therapy started. Therefore, the tumor response to IL-2 was suggested to depend on NK activity and LAK activity.