Flow cytometric determination of ploidy in prostatic adenocarcinoma: a comparison with seminal vesicle involvement and histopathological grading as a predictor of clinical recurrence.

Flow cytometry was used to evaluate 88 deparaffinized radical prostatectomy specimens to compare deoxyribonucleic acid ploidy in prostatic adenocarcinoma as a predictor of disease progression with other well documented predictors of clinical recurrence. Aneuploidy, Gleason grade and seminal vesicle involvement were nonindependent variables, and all correlated to statistical significance with disease recurrence. The incidence of aneuploidy in the total population was 51 of 88 (58 per cent). Aneuploidy was found in 25 of 28 primary tumors (89 per cent) from patients who subsequently had recurrent disease. Aneuploidy was noted in 40 of 59 specimens (68 per cent) exhibiting seminal vesicle involvement, compared to 11 of 29 (38 per cent) without seminal vesicle involvement (p less than 0.01). The probability of an interval free of disease of 60 months was calculated by Kaplan-Meier analysis to be 85 per cent in diploid specimens compared to 9 per cent in aneuploid specimens (p less than 0.001), and 87 per cent in the absence of seminal vesicle involvement compared to 28 per cent in the presence of seminal vesicle involvement (p less than 0.003). The probability of remaining free of disease in patients exhibiting concomitant diploidy and seminal vesicle involvement (17) was 73 per cent compared to 8 per cent in those with aneuploid specimens and seminal vesicle involvement (p less than 0.004). The incidence of recurrence in patients with Gleason sums of 7 or less was 22 per cent compared to 62 per cent in patients with Gleason sums of greater than 7. There was a 29 per cent incidence of recurrence in intermediate grade tumors (Gleason sum 5 to 7) but only 5 per cent of the patients with intermediate grade diploid tumors had recurrent disease. In conclusion, the recognition of a deoxyribonucleic acid aneuploid stem line in a primary prostatic adenocarcinoma is correlated statistically with a greater likelihood of seminal vesicle invasion and subsequent development of recurrent disease. The markedly increased probability of remaining free of disease in diploid patients, even in the presence of seminal vesicle involvement, suggests that routine flow cytometric analysis in prostatic adenocarcinoma would significantly enhance prognostic stratification.