[Successful preoperative interferon-alpha therapy of advanced renal cell carcinoma with tumor thrombus extending into the inferior vena cava: a case report].

We report a case of renal cell carcinoma in which interferon-a therapy was effective in reducing the tumor thrombus extending into the inferior vena cava. A 66-year-old man was referred to our hospital with a complaint of macroscopic hematuria, cough and general fatigue. We made a diagnosis of a left renal cell carcinoma with tumor thrombus by imaging examination. Because his performance status was 3, a radical operation was considered risky. Twenty-two months after the start of interferon-a therapy, the tumor thrombus was markedly reduced in size, and the clinical response was evaluated as partial response by the response criteria for urological cancer treatrment. Because of improvement of the performance status and downsizing of tumor thrombus, we performed radical nephrectomy. Pathological examinations revealed that viable renal cell carcinomas were found in the primary lesion and the tumor thrombus. In some cases, interferon-alpha therapy is useful and safe in the treatment of the tumor thrombus. Furthermore, radical nephrectomy and complete resection of the tumor thrombus prolongs postoperative survival.