The prognostic value of deoxyribonucleic acid flow cytometric analysis in stage D2 prostatic carcinoma

This study was designed to compare the prognostic potential of tumor grade and ploidy status in patients with stage D2 prostate cancer. Two outcome groups were selected on the basis of survival after orchiectomy: a bad outcome group consisting of 66 patients who died of the disease within 12 months and a good outcome group comprising 37 patients who survived beyond 5 years. Tumors were classified histologically as well (17%), moderately (17%) or poorly (66%) differentiated. Tumor grade was a significant predictor of outcome, with 76% of poorly differentiated tumors in the bad outcome group and 65% of well differentiated tumors in the good outcome group (p less than 0.005). Deoxyribonucleic acid (DNA) ploidy analysis was performed on formalin fixed, paraffin embedded samples of the primary tumor to yield 97 final tracings that were classified using set criteria for DNA ploidy status. Over-all, 54% of the tumors were nondiploid (33% aneuploid and 21% tetraploid) and the remaining 46% were diploid. DNA ploidy status was a significant indicator of outcome (p less than 0.001), with 64% of diploid tumors in the good outcome group and 88% of the nondiploid tumors in the poor outcome group. Tetraploid tumors behaved no differently from other nondiploid tumors. We conclude that DNA ploidy status and tumor grading are significant independent predictors of outcome after orchiectomy and when combined yield important additional prognostic information.