Significance of conventional and new prognostic factors for locally confined renal cell carcinoma

Abstract

Background. The prognosis of patients with locally confined renal cell carcinoma is variable. To improve the prognostic knowledge and select patients at high risk, additional prognostic parameters are needed. Methods. The significance with respect to survival and tumor recurrence of “classic” and “new” prognostic parameters has been examined by following 41 patients with locally confined renal cell carcinoma after nephrectomy (mean follow-up, 5,2 years). The significance of histologic grade, tumor stage, Ki-67 index, proliferating cell nuclear antigen index, ³H-thymidine labeling index, tumor ploidy status, and tumor growth after xenotrans-plantation into nude mice (GAX range) was tested using the Kaplan-Meier plots by the log rank test or Tarone's test and also by the Cox multiple hazard regression analysis. Results. Tumor stage (P < 0.0025), histologic grade (P < 0.005), Ki-67 index (P < 0.006), and GAX range (P < 0.00004) were found to be significant prognostic parameters for survival and tumor recurrence using single-factor analysis. Applying the multivariate analysis, the combination of the “new” factors, GAX range and Ki-67 index, resulted in even a higher prognostic relevance than the combination of the “classic” prognostic factors, tumor stage and histologic grade. The calculated prognostic index based on the results of the Cox analysis, which, except for stage and grade, included the Ki-67 index, was shown to be highly correlated with survival (P = 0.00002) and tumor recurrence (P = 0.0004). Its prognostic validity was studied with the receiver operating characteristicss procedure and was found to be considerably superior to that of the two conventional prognosticators. Conclusions. The additional determination of the Ki-67 labeling index increases the prognostic assessment of patients with locally confined renal cell carcinoma. Cancer 1995; 76:296–306.