Prognostic Significance of Ploidy, MIB-1 Proliferation Marker, and p53 in Renal Cell Carcinoma

Abstract

BACKGROUND: Pathologic stage is currently the best prognostic factor for predicting outcomes in renal cell carcinoma. The objective of this study was to evaluate the role of DNA ploidy, p53, and Ki-67 (MIB-1) as individual and combined prognostic factors for survival in patients with renal cell carcinoma (RCC). STUDY DESIGN: From 1995 to 2004, 117 patients (78 men and 39 women; mean age 57.34 years), undergoing partial (n = 22) or radical (n = 95) nephrectomy for renal cell carcinoma were retrospectively analyzed. Analysis of MIB-1, p53, and DNA ploidy was performed. Disease-free and overall survival was calculated using Cox proportional hazard models. A combined score was given to incorporate p53, MIB-1, and ploidy as a single variable. RESULTS: On univariate analysis, tumor size, nuclear grade, MIB-1 <10% (p = 0.0059), ploidy (p = 0.0124), pathologic stage group, metastasis at time of operation, and combined score (p = 0.0024) were markedly associated with disease-free survival. On multivariate analysis, only metastasis and pathologic stage were pronounced. For overall survival, size, nuclear grade, MIB-1 <10% (p = 0.0167), pathologic stage group, metastasis, and combined score (p = 0.0456) were pronounced on univariate analysis. Only metastasis was pronounced on multivariate analysis. CONCLUSIONS: We incorporated a combined score to evaluate MIB-1, ploidy, and p53 as a single variable. A combined score is able to give a stronger predictive value of the cellular characteristics of each tumor. Individually and combined with p53, MIB-1, and ploidy were of prognostic significance on univariate analysis. Pathologic stage and presence of metastasis remain the best predictors of disease-free survival.