Role of cyclin D1 immunoreactivity and AgNOR staining in the evaluation of benign and malignant lesions of the prostate

PURPOSE Prostatic carcinoma is a common and growing public health problem. Histological evaluation is fairly adequate for assessing tumor differentiation, but tumor proliferative activity is difficult to measure. Increasing evidence suggests that the factors controlling cell cycle progression also modulate the rate of ribosome biogenesis. Despite the influence of cyclin D1 and argyrophilic nuclear organizer region (AgNOR) on prostate cancer proliferation, few studies have evaluated the diagnostic importance of these markers. Therefore, the present study was carried out to analyze the diagnostic value of the proliferative markers cyclin D1 and AgNOR in various prostatic lesions and to determine whether any association or relation between these markers and different Gleason grades exists. METHODS A total 50 cases of various prostatic lesions were studied. Tumor grade, AgNOR staining, and cyclin D1 expression were evaluated in all cases. Correlations between the intensity and differential localization of these markers and Gleason grades were evaluated. RESULTS The mean AgNOR count in cases of prostatic intraepithelial neoplasia was high compared with cases of benign prostatic hyperplasia (BPH) but lower than that of carcinoma cases. The intensity of cyclin D1 expression was high in carcinoma. A total of 14 cases (46.67%) showed strong positivity. No significant correlation was found between the intensity of cyclin D1 expression, AgNOR count, and histologic grades of prostatic carcinoma, whereas a significant correlation was observed between intensity and percentage expression of cyclin D1 in BPH and carcinoma (P<0.01). Nuclear as well as cytoplasmic positivity was seen among various grades of carcinoma. CONCLUSIONS AgNOR count and cyclin D1 may be helpful in distinguishing between BPH and carcinoma of the prostate but may not be used as reliable indicators of the grade of prostatic adenocarcinoma because of overlapping values in various grades. However, further studies on larger samples are required to elucidate the role of these markers in identification of premalignant lesions.