5 Alpha-reductase activity in human prostate cancer is related to the histological differentiation of the tumour.

We have measured the activities of two androgen metabolizing enzymes in tissue obtained from thirty-nine patients with carcinoma of the prostate (CaP). The enzyme activities were correlated to the histological differentiation of the tumours based on the Gleason Score and also compared to the activities measured in fourteen age matched patients with nodular prostatic hyperplasia (BPH). Although the mean values for the 5 alpha-reductase in CaP (9.29 +/- 1.47 pmol/mg protein/30 min) were found to be significantly lower than the corresponding values in BPH (16.26 +/- 3.04 pmol/mg protein/30 min) (P less than 0.05), there were nonetheless significant differences within the cancer group and these were totally dependent on the degree of differentiation of the tumour. A progressively suppressed enzyme activity was measured as the carcinomatous tissue became more anaplastic. No correlation was, however, observed between tumour bulk which was also estimated histologically and 5 alpha-reductase, indicating that the activity of this enzyme is purely a function of the histological grade of the cancer and as such 5 alpha-reductase could be used as a biochemical marker for tumour differentiation. We also measured the 3 alpha (beta)-hydroxysteroid dehydrogenase activities in cancer of the prostate but our findings indicated no significant differences between the various stages of the cancer. Furthermore we were unable to correlate the activities of this enzyme with that of the 5 alpha-reductase. Nonetheless two interesting patterns relating to the 3 alpha (beta)-hydroxysteroid dehydrogenase emerged.(ABSTRACT TRUNCATED AT 250 WORDS)