Cytoreductive Nephrectomy in Patients With Metastatic Renal Cancer: A Combined Analysis

A total of 331 patients were randomized to 2 identical protocols comparing cytoreductive nephrectomy plus interferon alpha-2b vs interferon alpha-2b alone in patients with metastatic renal cancer, in whom the primary tumor was present and believed to be resectable. The primary end point for each trial was overall survival with a secondary end point of the response rate. Patients were stratified at pre-randomization by performance status (0 or 1), site of metastases (lung only vs other) and disease measurability. All results were analyzed by intent to treat criteria. Assuming a median survival of 1 year for interferon only, the Southwest Oncology Group trial was designed to detect a 50% improvement in median survival duration and a 15% improvement in response rate with a power of 0.85. The European Organization for the Research and Treatment of Cancer accrued an additional 80 patients in that study.

The combined analysis of these 2 trials yielded a median survival of 13.6 months for nephrectomy plus interferon vs 7.8 months for interferon alone. This difference represents a 31% decrease in the risk of death (p = 0.002). There was no evidence of a difference in the size of the treatment effect according to pre-randomization stratification factors.