Cell proliferation, apoptosis and prognosis in patients with metastatic prostate cancer.

Background: Since tumor growth is determined by an imbalance between cell growth and cell death, we assessed the incidence of cell proliferation and apoptosis in biopsy specimens from patients with metastatic prostate cancer treated with endocrine therapy.

Materials And Methods: In fifty-five patients with untreated metastatic prostate cancer, proliferation and apoptotic indices were determined by detection of Ki-67 immunostaining and the in situ end-labeling technique, respectively. The clinical parameters and prognosis of the patients were evaluated.

Results: The proliferation index in poorly-differentiated cancer was significantly higher than that in moderately-differentiated cancer. Good-responders to hormone therapy, as assessed by the decrease in prostate-specific antigen after the endocrine therapy, were likely to have a low proliferation index. The patients with a low proliferation index had better progression-free and cause-specific survival compared to those with a high proliferation index. Proliferation indices were significantly correlated with apoptotic indices.

Conclusion: Metastatic prostate cancer shows an increase of malignant potential as assessed by the number of Ki-67-positive cells and proliferation in each tumor is correlated with apoptosis.