CELL-PROLIFERATION IN DYSPLASIA OF THE PROSTATE - ANALYSIS BY PCNA IMMUNOSTAINING

Patterns of cell proliferation in the prostate were compared between b enign epithelium and dysplasia. Proliferating cell nuclear antigen (PC NA) immunostaining was used to quantitate proliferation, and basal cel ls were tallied separately from secretory cells with the aid of kerati n immunostaining. Using a novel technique, absolute cell densities (ce lls/mm) were determined and used to calculate growth fractions. In ben ign epithelium, 83% of PCNA(+) cells were basal cells, while only 7% o f PCNA(+) cells in dysplasia were basal cells and there was a clear se paration between groups. This dramatic shift of the proliferative comp artment to the secretory cells in dysplasia was accompanied only by a moderate increase in overall secretory cell density and moderate reduc tion in basal cell density, but these ranges overlapped those of benig n epithelium. The median PCNA(+) secretory cell ''growth fraction'' wa s 0.12% in benign epithelium and 1.06% in dysplasia. The findings pres ented give further support to the concept that dysplasia represents an evolutionary stage in the malignant transformation of prostatic epith elium. The patterns of change in PCNA immunostaining may reflect certa in aspects of the biologic nature of malignant transformation. (C) 199 5 Wiley-Liss, Inc.