CLINICAL-SIGNIFICANCE OF IMMUNOHISTOCHEMICALLY DETECTABLE P53 PROTEINRENAL-CELL CARCINOMA

Objective: To elucidate the clinical significance of p53 protein in re nal cell carcinoma (RCC). Materials and Methods: The p53 protein in th e paraffin-embedded materials taken from 72 patients with RCCs was eva luated immunohistochemically and was compared with the histological fi ndings, expression of proliferating cell nuclear antigen (PCNA), genet ic instability as assessed by 2c deviation index (2cDI) and 5c exceedi ng rate (5cER) as well as clinical outcome. Results: The p53 positivit y was demonstrated only in a localized and/or focal area of the cancer ous tissue. The positive rate of p53 protein was 40.3% in this study. The p53 protein significantly correlated with nuclear grade as well as PCNA expression (p < 0.001 and p < 0.01, respectively). Although ther e was a wide scatter of 2cDI and 5cER values between p53 positive and negative RCCs, the RCC with positive p53 exhibited significantly highe r values in 2cDI as well as 5cER, as compared to that with negative p5 3 (p < 0.02 and p < 0.005, respectively). However, some of the RCCs wi th negative p53 showed relatively higher values in 2cDI and 5cER. Usin g univariate analysis, the prognostic relevance was noted in T, N, M c ategories, age and p53 positivity, while it was not in 2cDI, 5cER and PCNA expression. Multivariate analysis demonstrated that N category an d p53 positivity were independently significant indicators in predicti ng survival. Conclusions: The presence of p53 protein might reflect th e genetic instability already occurred. The p53 positivity reflecting a high cellular proliferation could afford an additional but useful in formation when predicting survival in patients with RCC.