IMMUNOHISTOCHEMICAL DETECTION OF PROLIFERATING CELL NUCLEAR ANTIGEN (PCNA) CYCLIN IN HUMAN PROSTATE ADENOCARCINOMA

Tissue specimens from 12 patients with adenocarcinoma of the prostate and 7 patients with benign prostate hypertrophy were stained by an indirect immunoperoxidase method using anti-proliferating cell nuclear antigen (PCNA) monoclonal antibody. The PCNA labeling index was determined by counting the number of PCNA-labeled cells in the tissue sections. Average PCNA labeling index of the benign prostate hypertrophy was 1.2 +/- 0.5%. Poorly differentiated tumors averaged 7.6 +/- 3.9% labeling versus 4.6 +/- 1.3% in moderately differentiated tumors, and well differentiated tumor in the series had a PCNA labeling index of 2.5 +/- 0.9%. The PCNA labeling indices for atypical hyperplasia were 1.9, and 4.1%, respectively. Our preliminary results suggest that the measurement of PCNA labeling index in prostate cancer may prove to be a new objective and quantitative assay of biological potential of individual tumor.