PATHOLOGICAL PARAMETERS AND FLOW CYTOMETRIC PLOIDY ANALYSIS IN PREDICTING RECURRENCE IN CARCINOMA OF THE PROSTATE

Recurrence of prostate cancer following radical prostatectomy is deter mined by the extent of local disease. Tumor volume and grade have impr oved our ability to predict extraprostatic extension, but tumors of in termediate volume and grade vary in their biologic behavior. To assess the prognostic significance of DNA ploidy, we performed flow cytometr y in 85 patients with prostate cancer volumes > 4 cm3. Post-radical pr ostatectomy serum prostate-specific antigen was used to prove recurren ce of cancer. Mean follow-up was 35 months (median 31 months). 26 pati ents (30%) had diploid histograms, 55 (65%) non-diploid histograms. In 4 cases (5%) the histograms were uninterpretable. Tumor volume and pe rcent of Gleason grades 4 or 5 separated the recurrent from nonrecurre nt groups in a highly significant manner (p < 0.001). When tested alon e, ploidy had no ability to predict recurrence (p = 0.26). However, in a subset of patients with 4-8 CM3 of cancer with < 30% Gleason grade 4 or 5 tumor, ploidy conferred significant additional prognostic infor mation (p < 0.005).