[Case report of advanced renal cancer that showed different responses to the alteration of therapeutic cytokines].

We report a case of advanced renal cancer that showed different responses to the alteration of therapeutic cytokines. A 73-year-old man presented with asymptomatic macrohematuria, and was diagnosed as right renal cancer (11 x 9 x 9 cm in diameter) with metastases to abdominal and mediastinal lymph nodes (cT3bN2M1, stage IV). Transluminal embolization of the right renal artery was performed, and then he was treated by intramuscular administration of natural human interferon (IFN)-alpha (Sumiferon; 6 x 10(6) units) three times a week. Four months later, lymph node metastases enlarged, and human interleukin-2 therapy (intravenous administration; 1.4 x 10(6) units) was initiated instead of IFN-alpha. However, lymph node metastases further enlarged and multiple lung metastases newly appeared in 5 weeks after the alteration of the therapy. Then, the treatment was switched to intramuscular administration of another natural human IFN-alpha (OIF; 5 x 10(6) units) three times a week. In 3 months after OIF administration, all lung metastases disappeared. Lymph node metastases have shown no progression for 9 months after the switch to OIF. Different responses to the two types of IFN-alpha in this case may be caused by the difference in the composition of IFN-alpha subtypes. Alteration of therapeutic cytokines, especially a switch from one type to another IFN-alpha may be one of worth attempts even if other cytokines are not effective.