Abstract:

Prostate carcinoma (PC) is the most common malignancy among males and it is the second most common cause of death due to cancer (after lung cancer) in men. Prostatic intraepithelial neoplasia (PIN) is a premalignant lesion described recently. The differentiation of PIN from BPH or PC is important. In this study, it was aimed to investigate the place of Ki-67, CD31, Laminin immunoreactivities and apoptotic index in the differentiation of PIN (accepted as a precursor lesion of PC) from BPH or PC. A total of 150 specimens (50 PC, 50 PIN and 50 BPH cases) which were evaluated and diagnosed in the Department of Pathology, Medical Faculty, Ataturk University between 1991– 2001 were included in the study. Ki-67, CD31 and Laminin were applied to the paraffin sections with immunohistochemical method. Additionally H&E stained sections were prepared from paraffin blocks from the same cases for the evaluation of apoptotic index. The staining was accepted as positive for Ki-67 if dark-brown stained nucleus is present, for CD31 if cytoplasms of endothelial cells are stained, and for Laminin if continuous linear staining of basal membrane under the prostatic glandular epithelium is observed.Ki-67 immunoreactivity was the highest in PC group and the lowest in the BPH group. Moreover, while Ki-67 immunoreactivity was significantly higher in PC group than in PIN group (p<0.001), the difference between PIN and BPH was p<0.05. Both CD31 immunoreactivity and apoptotoic index were found to be the highest in PC group and the lowest in BPH group. In the comparison of groups, PC group had higher CD31 immunoreactivity and apoptotic index values than in both PIN (p<0.001) and BPH (p<0.001) did. As a conclusion, it was suggested that Ki-67, CD31 immunoreactivities and apoptotic index were useful in the differentiation of PIN from BPH and PC. For Laminin, although it may be useful in the differentiation of PIN from PC, it cannot be used for PIN – BPH differentiation.

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