Flow cytometric DNA ploidy analysis in prostatic adenocarcinoma: a comparison with clinical stage, histopathological grade and prognostic significance

Cheon, Jun; Chae, Yang Seok; Cho, Jae Heung

Abstract

Recent studies suggest the flow cytometric DNA ploidy analysis may be useful in defining the biologic behavior and prognosis in prostatic adenocarcinoma. Flow cytometric nuclear DNA ploidy analysis was used to study the relationship between DNA ploidy, clinical stage and histopathological grade in thirty two patients with prostatic adenocarcinomas diagnosed from 1987 to 1990. The incidence of aneuploidy in the total population was 18 of 32 (56.3%). The frequency of aneuploidy increased with advancing stage and 63.2% of carcinomas with distant metastases were aneuploidy. Aneuploidy was more frequent in high Gleason sum carcinomas than in low. The incidence of aneuploidy in carcinomas with high Gleason grade (Gleason sum 8 to 10) was 77.8%. comparing to 33.3% in low Gleason grade (Gleason sum 2 to 4). When carcinomas classified according to both DNA ploidy and degree of glandular differentiation, then subgroups with the highest and lowest degree of malignant potential became apparent. None of diploid tumors with low Gleason grade (Gleason sum 2 to 4) formed metastasis, but 71.4% of aneuploidy tumors with high Gleason grade (Gleason sum 8 to 10) formed metastases. The influence of DNA ploidy on survival was examined with Kaplan-Meier method and the generalized Wilcoxon test. Overall, the patients with diploid tumor had a survival advantage over patients with aneuploid tumor (p<0.05). In patients with stage C and D, there was increasing tendency of survival in diploid group. In conclusion flow cytometric determination of DNA ploidy in prostatic adenocarcinoma is correlated strongly with clinical stage and Gleason sum and can be expected to be a valuable adjunct b clinical stage and histopathological grade in the assessment of malignant potential of prostatic adenocarcinoma.