[Heterogeneity of nucleolar distribution in prostatic cancer. Comparison with the cytological grade and DNA content]

Thirty seven prostatic carcinomas at a D2 metastatic stage were studied after transrectal fine-needle aspiration in a prospective multicentric study. The number and the distribution of nucleoli were compared, in each cytological grade, to the flow cytometric nuclear DNA content. In 9 grade I, 13 grade II and 15 grade III the proportion of bimodal DNA profiles was 11%, 30.7% and 66.7%. The total number of nucleoli per 100 nuclei was respectively 114.11 (SD = 8.12), 158.31 (SD = 47.97) and 194.40 (SD = 58.42). A statistically significant difference (t = 2.78; P = 0.009) was found between the total number of nucleoli of unimodal (22 cases) and bimodal DNA profiles (15 cases). However, no significant difference in nucleolar parameters was found between unimodal (14 cases) and bimodal DNA profiles (14 cases) in cytological grades II and III. These results suggest that the nucleolar parameters do not necessarily parallel the increase in the nuclear DNA content, and that the two factors are independent of one another.