p53 expression in human renal cell carcinoma: an immunohistochemical study and a literature outline of the cytogenetic characterization.

In this study both the incidence and pattern of p53 over-expression in various histological subtypes of a series of 36 cases of renal cell Grawitz carcinoma, partially studied in a previous paper, were analyzed. This series consisted of these histologic subtypes: clear cell non papillary (18 cases), clear cell papillary (2 cases), granular cell (5 cases), mixed (clear and granular cell) (9 cases) and spindle cell (2 cases). At present, our aim was, firstly, to see which were the best technical conditions for detection of p53 in the available paraffin-embedded tumor specimens, using several antibodies, specific for various epitopes; secondly, to investigate if some relation might exist between this expression and the histological features of these tumors. Twenty-five per cent (9/36 cases) resulted p53 immunoreactive, the highest percentage being represented in the papillary clear and granular cell carcinomas; low expression was detected in 11 cases (30%) and no reactivity in 16 cases (44%). Neither technical or dilution modifications proved to transform these latter results; however, detection was maximal using the CM-1 polyclonal rabbit antiserum. Thus, in RCC, expression of p53, analyzed in the light of the cytogenetic characterization through a literature review, resulted at low frequency. This finding means that mutation of the p53 gene are not frequent in the neoplastic transformation in RCC. Nevertheless, in spite of the small number of cases and of the short follow-up period of this study, detection of p53 positivity in tumors with either high grade and stage or high proliferative activity could suggest that p53 mutations lead to tumors of a more aggressive type.(ABSTRACT TRUNCATED AT 250 WORDS)