Expression of p53 and bcl-2 in primary locally confined renal cell carcinomas: no evidence for prognostic significance.

p53 tumor suppressor gene mutations are present in a wide variety of human cancers, and the bcl-2 gene product is considered to prevent apoptosis. However, the significance of these gene products for the aggressiveness of the tumor and correspondingly for the prognosis of patients with renal cell carcinoma (RCC) is unclear. The expression of p53 and bcl-2 gene products was studied immunohistochemically using formalin-fixed paraffinembedded tumor samples of 31 locally confined RCC of patients treated with radical nephrectomy. The significance of these 2 parameters, in addition to tumor stage and malignancy grade, was tested with regard to survival and time of no recurrence using Kaplan-Meier-plots by the log rank test or Tarone's test and the Cox multiple hazard regression analysis (mean follow-up 5.4 years). Only 5 of the 31 RCCs stained positively for p53 and only 2 showed positive bcl-2 staining of tumor cells. Tumor stage (P < 0.002) and malignancy grade (P < 0.007) were statistically significant prognostic parameters for both survival and disease-free period by univariate analysis. In contrast, the detection of either p53 (P > 0.67) or bcl-2 gene product (P > 0.28) had no prognostic impact. Also in the multivariate statistical analysis, neither of the 2 parameters i.e. p53 and bcl-2 expression significantly improved the prognostic impact of the conventional prognosticators stage and grade, if applied in addition. The expression of p53 and bcl-2 seems unimportant as a prognostic factor in locally confined RCCs.