DNA ploidy, S phase fraction and G2 fraction as prognostic determinants in prostatic adenocarcinoma.

Abstract

The results of DNA flow cytometry (FCM), histological features and clinical stage of prostatic adenocarcinoma were correlated to outcome in 91 patients during a mean follow-up period of 15.6 years. Aneuploidy was detected in 33 (36%) tumours, and 59 (64%) tumours were diploid. Eighteen (20%) tumours showed a tetraploid DNA index. The frequency of tetraploidy increased towards high-stage and high-grade tumours. Aneuploidy, high S phase fraction (SPF) and G2 fraction were significantly related to clinical stage, histological grade and perineural infiltration. Progressing tumours (T category) had higher SPF values (p = 0.0248), and progression in N (p = 0.0122) and M categories (p = 0.0021) was related to high G2 fraction as well. In T1-2 tumours, DNA ploidy (p = 0.0280) and SPF (p = 0.0230) predicted progression, whereas histological grade had no significant predictive value. The clinical stage (T) predicted crude survival (p = 0.0005). Results show that FCM gives prognostic information in prostatic adenocarcinoma beyond that of histological grading.