Combination of interferon and radiotherapy in advanced renal cell carcinoma

The efficacy of combined use of interferon and radiotherapy in renal cell carcinoma was investigated. In a preliminary experiment, interferon and radiotherapy were used alone and in combination to treat renal cell carcinoma transplanted into nude mice. Combined use of interferon and radiotherapy was shown to have significant antitumor effects compared with either therapy. The survival period with combined therapy was about twice as long as with the individual modality alone. Based on the results of the preliminary experiment, we performed combined interferon and radiotherapy in 10 patients with advanced renal cell carcinoma. Interferon-α was injected intramuscularly at 3 x 106 IU once daily on continuous days for a total dose of 90 to 306 x 106 IU (mean 201 x 106 IU). Radiotherapy was performed at 2.0 to 2.5 Gy per dose 5 times a week for a total dose of 40 to 66 Gy. Complete response was obtained in one patient, partial response in two patients, and no change was observed in the remaining 7 patients, for an efficacy rate of 30%. The principle adverse effects, fever and leukocytopenia were noted in 10 and 4 patients, respectively, but none of the adverse side effects were serious. (author)