Efficacy of adjuvant interferon-alpha therapy following curative resection in renal cell carcinoma: before the molecular targeting therapy era.

OBJECTIVE Although present treatment programs for renal cell carcinoma (RCC) typically involve molecular-targeting drugs, interferon-alpha (IFN-alpha) remains an important therapeutic drug for this cancer. METHODS We evaluated the effect of adjuvant therapy in 508 patients with RCC following curative surgery. Patients were classified into one of the two categories based on the duration and the total dose of IFN-alpha treatment. RESULTS Median follow-up time was 65.5 months. Overall survival rates at 5, 10, 15 and 20 years were 88.8%, 80.5%, 69.6% and 54.1%, respectively. Cause-specific survival rates at 5, 10, 15 and 20 years were 95.0%, 89.1%, 83.0% and 83.0%, respectively. Cox's proportional hazard model revealed that C-reactive protein, T classification, histological grade and age were significantly independent factors indicative of a poor prognosis. Our examination of the 253 patients diagnosed as pT1-2N0M0 who underwent adjuvant IFN-alpha therapy following surgery found that the therapy was not significantly associated with either cause-specific or disease-free survival. With regard to effects of duration of therapy and total dose of IFN-alpha, patients with a total IFN-alpha exposure of > or = 180 x 10(6) international units (IU) had a better prognosis than those exposed to <180 x 10(6) IU. CONCLUSIONS Adjuvant therapy using large doses of IFN-alpha may improve the prognosis of patients with RCC following curative resection, and the new possibility of IFN-alpha therapy merits further investigation.