Aim: To investigate the long-term efficacy of postoperative interferon-alpha (IFN-alpha) adjuvant therapy in preventing recurrence in non-metastatic renal cell carcinoma treated with radical nephrectomy and to identify related prognostic markers.
Methods: Long-term follow-up was conducted to study rates of survival and non-recurrence in 88 subjects following radical nephrectomy for non-metastatic disease.
Results: The overall survival rate was 90% at 5 years and 88% at 10, with corresponding non-recurrence rates of 81% and 74%. Survival rates reviewed by preadministration pT stage showed a falling tendency from T1 through to T3 in line with pathological progression; when cases at stage pT1b or below were compared with those at stage pT2 or above, the latter showed a tendency to lower survival rates (P = 0.0966, Breslow-Gehan-Wilcoxon). Similarly, non-recurrence rates tended to fall in line with pathological progression, with a significant difference found in the comparison of cases at stage pT1b or below with those at stage pT2 or above (P = 0.0265, log-rank, Mantel-Cox). Duration of IFN-alpha administration showed a tendency to positive correlation with long-term survival (P = 0.3765, Breslow-Gehan-Wilcoxon). Non-recurrence rate was not found to differ according to duration of administration. Comparison of groups with normal and abnormal preadministration immunosuppressive acidic protein values showed that the normal group tended to have higher rates of survival and non-recurrence (P = 0.3371, Breslow-Gehan-Wilcoxon).
Conclusions: Immunosuppressive acidic protein values appear to be a useful predictive marker for recurrence. A randomized trial, examining long-term outcome according to tumor stage and variables such as duration of administration, dose, administration time, and dosing schedule is required.