Cell proliferation and apoptosis in prostate needle biopsies with adenocarcinoma Gleason score 6 or 7.

OBJECTIVE: To analyze whether cell proliferation and apoptotic indexes in needle biopsies with prostate cancer Gleason 6 or 7 can identify more objectively Gleason score 6 or 7 in needle biopsy samples.

STUDY DESIGN: Seventy patients diagnosed by needle biopsy and treated by radical prostatectomy were included. Fifty cases were Gleason score 6 and 20 were Gleason 7. Twenty-two cases were organ-confined and 48 nonorgan-confined. Histologic sections from needle biopsies were stained for cell proliferation using the MIB 1 (Ki67) antibody and in situ end-labeling technique for apoptosis and recorded as the percentage of positive cells. Statistical analysis included Student's t-test, Pearson's test, and logistic regression analysis.

RESULTS: We found increased apoptotic and proliferation indexes from Gleason 6 to 7, and from organ-confined to non-organ-confined. Apoptotic index was not associated to stage or Gleason score. We identified an association between cell proliferation and Gleason score indicating that higher proliferation index is associated with a higher probability of presenting a Gleason score 7. There was no association between pathologic stage and cell proliferation.

CONCLUSION: Cell proliferation and apoptosis can distinguish a subset of aggressive lesions in needle biopsies with Gleason 6 or 7 prostate adenocarcinoma.