Nucleolar organizer regions in prostate cancer.

A silver colloid technique for the staining of nucleolar organizer regions (NORs) was applied to paraffin sections of 52 clinical prostate cancers, 5 incidental carcinomas of the prostate, 12 benign prostatic hypertrophy (BPH) specimens and 7 normal prostates. The mean numbers of silver-stained NORs (AgNORs) in these lesions were 3.12 +/- 0.52 in clinical cancer, 2.65 +/- 0.64 in incidental cancer, 1.66 +/- 0.16 in BPH, and 1.76 +/- 0.22 in normal prostate. There was a statistically significant difference in agNORs numbers between cancer and benign prostatic tissues (p < 0.001). However, no significant difference was observed in AgNORs numbers between incidental and clinical carcinoma of the prostate. In clinical cancer, only poorly differentiated adenocarcinoma showed a statistically larger number of AgNORs than the well or moderately differentiated group (p < 0.02). Correlation between AgNORs numbers and clinical stage was not obvious. There was no relationship between the number of AgNORs and serum values of tumor markers such as PAP, PSA and gamma-Sm. Moreover, the AgNORs numbers did not show a relation to decreasing rates of serum marker levels during successful anti-androgen therapy. If the patients with prostate cancer were divided into two groups by 2.9 of AgNORs number, the group with the smaller number of AgNORs (n = 14) was found to have a tendency towards a longer disease-stabilizing period than the larger group (n = 17).