Progression and survival in prostatic adenocarcinoma: a comparison of clinical stage, Gleason grade, S-phase fraction and DNA ploidy

Abstract

Clinical data were reviewed in 325 patients with prostatic adenocarcinoma followed up for a mean of 13 years. Paraffin-embedded tumour biopsy specimens from the primary tumours were available for flow cytometry (FCM) in 273 cases. Intra-tumour heterogeneity in DNA index (DI) was found in 4% of the tumours (54 cases were analysed). S-phase fraction (SPF) and DNA ploidy were significantly interrelated. Aneuploidy and high SPF were significantly related to both a high T category and high Gleason score. The progression in T1-2M0 tumours was related to Gleason score (P = 0.009), DNA ploidy (P = 0.006) and SPF (P = 0.007), while the Gleason score (P = 0.0013), DNA ploidy (P = 0.002) and SPF (P < 0.001) had prognostic value in univariate survival analysis. In the entire cohort, the T category (P < 0.001), M category (P < 0.001), Gleason score (P < 0.001), DNA ploidy (P < 0.001) and SPF (P < 0.001) were significant prognostic factors. In Cox's analysis, the M category (P < 0.001), Gleason score (P < 0.001), T category (P = 0.003), age (P = 0.001) and SPF (P = 0.087) were independently related to prognosis. In the T1-2M0 tumours, Gleason score (P < 0.001), T category (P = 0.022) and SPF (P = 0.058) were independent predictors. A novel classification system in which the DNA ploidy or SPF and the Gleason score were combined was found to be of significant prognostic value in all M0 tumours (P < 0.001). The results suggest that FCM can be used as an adjunct to conventional histological assessments for determination of the correct prognostic category in prostatic adenocarcinoma.