Cell kinetics by bromodeoxyuridine labeling and deoxyribonucleic acid ploidy in prostatic carcinoma needle biopsies

We studied 63 prostate carcinomas in needle biopsies after labeling in vitro by incubating the entire biopsy specimen with tritiated thymidine or bromodeoxyuridine before fixation. Biopsies from 176 patients were labeled, of which 98 were benign and 78 were carcinomas (15 carcinomas were excluded because of scant tissue). The procedure did not interfere with histological diagnosis. Median labeling index was 0.87% (range 0.1 to 29.3%). A labeling index exceeding 3% was unusual but it may indicate the potential for rapid clinical progression. Deoxyribonucleic acid (DNA) flow cytometry was performed on the last 44 carcinomas using cells shed by the prostatic needle biopsy tissue samples during transportation to the pathology laboratory. A sufficient number of cells were obtained for analysis in 37 cases, of which 6 were DNA aneuploid. Labeling index correlated with Gleason histological grade and score, and data from the 6 DNA aneuploid carcinomas suggest association between DNA aneuploidy and a high labeling index. Estimates of percentage of S-phase cells by flow cytometry did not correlate with variables other than DNA index, and appear to have been affected by a high noise-to-signal ratio (few proliferative cells relative to cellular debris) and inability to discriminate between benign and carcinomatous cells.