Discrimination between normal, hyperplastic and malignant human prostatic tissues by enzymatic profiles.

A relative enzymatic index has been developed which differentiates normal, hyperplastic (BPH) and malignant human prostatic tissues. Enzymatic activities have been calculated at Vmax conditions in 10 normal, 14 BPH and 11 carcinoma samples. Five enzymes have been assayed: 1) 5 alpha-reductase, 2) 3 alpha-hydroxysteroid oxidoreductase, 3) 3 beta-hydroxysteroid oxidoreductase, 4) 17 beta-hydroxysteroid oxidoreductase and 5) acid phosphatase. The following observations were made when comparing individual enzymatic activities between the 3 tissue groups: 1) mean 5 alpha-reductase activity was lower in carcinoma than in both normal prostate and BPH (p less than 0.05), 2) mean 3 alpha-hydroxysteroid oxidoreductase and 3 beta-hydroxysteroid oxidoreductase activities were greater in carcinoma than in BPH (p less than 0.05) and 3) mean acid phosphatase activity was higher in BPH than in both normal prostate and carcinoma (p less than 0.01). The absolute enzymatic activities were then expressed as relative activities by dividing each absolute value by the mean value for that enzyme in normal prostatic tissue. Relative enzymatic activities were used to derive the ratio: (Formula: see text) The mean value of this ratio was statistically different in normal, BPH and carcinoma tissue (p less than 0.01). The mean value was 3.6 times higher in BPH than in normal tissue, and was 3.8 times higher in normal tissue than in carcinoma. This suggests that BPH and carcinoma diverge in opposite directions biochemically from normal prostatic growth and supports histologic evidence that the 2 neoplastic conditions have a different pathogenesis rather than being part of the same disease spectrum.