NUCLEOLAR ORGANIZER REGIONS AND PCNA EXPRESSION IN PROSTATIC CANCERS

Argyrophilic nucleolar organizer regions (AgNOR) of 79 prostatic adeno carcinomas, and an immunohistochemical stain using a monoclonal antibo dy against proliferating cell nuclear antigen (PCNA) of 54 prostatic a denocarcinomas, obtained by needle biopsy and transurethral resection of the prostate between 1986 and 1989, were investigated. A morphologi cal classification was devised to count silver dots based on the relat ions between intra- and extra-nucleolar AgNOR (type A, a, C and D). To tal AgNOR counts were significantly higher in carcinoma (4.2 +/- 1.57) than in the benign prostatic lesions (1.90 +/- 0.24). Count differenc es of AgNOR were evident in histological differentiation, nuclear anap lasia, and presence of nucleoli, mitosis, lymphatic invasion and vascu lar invasion. Higher total AgNOR counts were almost always associated with type B and C AgNOR (intranucleolar AgNOR), but were not associate d with type A (nucleolus without small dot) nor type D (extra-nucleola r AgNOR). This study shows the diagnostic value of AgNOR in prostatic cancer, and the importance of morphological classification of AgNOR. T he survival of patients with higher AgNOR counts (greater than or equa l to 4.3) was significantly poorer than survival of those with lower A gNOR counts (<4.3). Significantly more PCNA positive cells were identi fied in cancer by immunohistochemical stain and correlated with the pr esence of mitosis, but there was no significant difference in survival rate groups classified by PCNA positivity. It is also suggested that PCNA can be a useful marker of cell proliferation in prostatic lesions , but the AgNOR counts were diagnostically and prognostically more val uable than immunohistochemical PCNA in prostatic lesions. The correlat ion between AgNOR and PCNA immunoreactivity was not significant.