[Prolonged complete remission of multiple organ metastases after radical nephrectomy induced by interferon-alpha therapy: a case report].

We experienced a case of advanced renal carcinoma that showed complete remission to interferon-alpha therapy. A 76-year-old male underwent radical nephrectomy for left renal cell carcinoma (pT3b pN0 M0, stage III). Two and a half months later, chest X-ray, computed tomographic (CT) scan and ultrasonography revealed multiple lung metastases and a hepatic metastasis simultaneously. We started the intramuscular administration of natural interferon-alpha (OIF, 5 MIU) combined with cimetidine everyday. It caused leukopenia, a possible side-effect of interferon-alpha. We reduced the dose to three times a week. The lung metastases and hepatic metastases disappeared after 5 and 12 months, respectively. After we reduced the dose to once a week, there was no evidence of disease for 21 months.