The association of immunoreactive p53 and Ki-67 with T-stage, grade, occurrence of metastases and survival in renal cell carcinoma

Background: The aim of this study was to clarify the association of p53 and Ki-67 protein expressions with tumor characteristics and survival in renal cell carcinoma (RCC). Materials and Methods: One hundred and seventeen patients were included in the study, 101 (86%) with conventional RCC according to the Heidelberg classification. Patients were divided into three groups with either primary metastases (pm), later metastases (lm), or no metastases (nm) during 7.5 years follow-up. Paraffin-embedded tissues were examined by immunohistochemistry utilizing anti-p53 and anti-Ki-67 antibodies, with a positive reaction cut-off of 10%. Results: In conventional RCC, there was more Ki-67 positivity in high T(tumor)-stage compared to low T-stage (p=0.036) and in pm patients compared to nm patients (p=0.007); p53 was not associated with T-stage or metastatic category. Co-expression of p53/Ki-67 was more common in pm patients than. in lm patients, but was not observed in nm patients (p=0.001). In the pm/lm group, p53 and Ki-67 expressions were associated with decreased survival (log-rank, p=0.030 and p=0.031, respectively). In lm patients, high T-stage (T3, T4) was associated with metastases-free survival (p=0.034) and overall survival (p=0.006). Conclusion: p53 and Ki-67 expressions are associated with aggressive tumor phenotype and decreased survival in metastatic RCC. Ki-67 alone was a stronger prognostic marker than p53 for development of metastases. Double positivity for p53 and Ki-67 expression in RCC patients seems to indicate a high metastatic probability.