HETEROGENEOUS EXPRESSION OF E-CADHERIN AND P53 IN PROSTATE-CANCER - CLINICAL IMPLICATIONS

Histologic grade and tumor volume are markers of malignant phenotype. More objective markers, however, have been sought for needle biopsy sp ecimens. The aim of this study was to evaluate how immunohistochemical expression of the potential prognostic markers E-cadherin and p53 in biopsy specimens relates to the expression of these markers in prostat ectomy specimens. Therefore, we analyzed 47 prostatectomy specimens an d their preoperative biopsy specimens. Fixation of surgical specimens and the immunohistochemical assay for both E-cadherin and p53 expressi on was optimized. All paraffin blocks containing areas of carcinoma we re submitted for immunohistochemical analysis. The prevalence of abnor mal p53 immunoreactivity was only 11%. In addition, abnormal p53 expre ssion was virtually restricted to cases that were already identified a s having a poor prognosis on the basis of the large volume and the hig h grade of their carcinomas. In 28% of the cases, we found abnormal im munoreactivity for E-cadherin. These cases revealed considerable heter ogeneity in topographic distribution of abnormal expression. The level of sensitivity to the detection of abnormal E-cadherin expression or abnormal p53 in the prostatectomy specimen was 15% and 60%, respective ly. In view of the inherent heterogeneity of E-cadherin expression and the low prevalence of abnormal p53 expression, we question the use of these markers for prognostic purposes in needle biopsy specimens. Unl ess representative sampling by needle biopsy can be assured, the use o f E-cadherin expression will be of most value in prostatectomy specime ns.