Apoptosis and nuclear shapes in benign prostate hyperplasia and prostate adenocarcinoma: comparison with and relation to Gleason score.

PURPOSE

To compare differences in the number of apoptotic bodies and nuclear shapes (size and roundness) between untreated benign prostate hyperplasia (BPH) and untreated advanced prostate adenocarcinoma (PCA) and to elucidate differences in apoptosis number and nuclear shapes with increasing malignant potentiality, by Gleason score, in PCA.

METHODS

A retrospective study was conducted on 40 patients with BPH and 12 patients with PCA I (Gleason score 2-4), 14 patients with PCA II (Gleason score 5-7) and 14 patients with PCA III (Gleason score 8-10). The frequency of apoptotic bodies (mean percentage calculated from 200 cells/high-power field over 10 fields) was examined on immunostain. Nuclear shapes were determined by an automatic image analyzer. Over 100 hyperplastic cells or cancer cells were detected by the image analyzer.

RESULTS

The mean number of apoptotic bodies in BPH and PCA I were not significantly different, but patients with PCA II and PCA III showed significantly higher numbers of apoptotic bodies than patients with BPH. Patients with PCA III had significantly more apoptotic bodies than patients with PCA I. Benign prostate hyperplasia nuclei had the smallest mean nuclear area and the largest mean nuclear peripheral ellipse among the four groups. The study showed that PCA I, II, III nuclei had significantly larger areas and a less circular shape than nuclei from patients with BPH. Nuclei from patients with PCA I were smaller in size and rounder than nuclei from patients with PCA III.

CONCLUSIONS

The present study clearly shows the presence of apoptosis in BPH and PCA and shows an increasing number of apoptotic bodies with higher cellular malignancy. The nuclear shapes in PCA were more irregular and larger in size with increasing cellular malignancy. As expected, nuclei in BPH were smaller in size and rounder than those of cancer nuclei.