Bcl-2 protein and DNA ploidy in renal cell carcinoma: do they affect patient prognosis?

Aim: The aim of the present study was to correlate bcl-2 protein expression and DNA-ploidy status with established prognostic parameters in renal cell carcinoma (RCC) and to examine their impact on disease progression and patient survival.

Methods: Both parameters were prospectively measured in 50 consecutive radical nephrectomy specimens using flow cytometry. They were correlated with the tumor grade, stage and histological type. Kaplan-Meier survival analysis for all parameters was performed.

Results: Bcl-2 protein expression was higher in RCC compared to normal renal tissue (P < 0.0001). Aneuploid tumors had higher bcl-2 expression compared to diploid tumors (P = 0.015). Bcl-2 expression and DNA content were not correlated with tumor histological types (P = 0.277/P = 0.419), grades (P = 0.690/P = 0.449), T categories (P = 0.637/P = 0.585) or stages (P = 0.726/P = 0.800). Median follow-up time was 46 months (range, 5-84) with a mean overall survival of 61.8 months (95% confidence interval, 53.7-69.9). Tumor stage was the only statistically important prognostic factor (P = 0.0045).

Conclusion: Although Bcl-2 expression was correlated with tumor DNA content, the prognostic value of these two parameters following radical nephrectomy was not established.