Decrease in creatine kinase in human prostatic carcinoma compared to benign prostatic hyperplasia.

Many previous studies have shown that a proportion of patients with carcinoma of the prostate have increased activity of the creatine kinase (E.C. 2.7.3.2) isoenzyme designated BB in sera from their peripheral blood. We have analyzed tissues from prostatic hyperplasia of 22 patients and from prostatic carcinoma of 23 additional patients. Prostatic carcinomas contain less (p less than 0.001) creatine kinase activity (units/g) than do prostates with benign prostatic hyperplasia. The facts that (a) histochemical studies that we performed confirmed the observation reported previously by others that creatine kinase activity is found primarily in the epithelial elements of hyperplastic prostates and prostatic carcinomas, (b) the carcinomas that we examined had, on the average, a somewhat larger epithelial component than the hyperplastic prostates that we examined, and (c) prostate cancer was found to contain less creatine kinase activity than hyperplastic prostates suggest that the epithelial cells in prostate cancers contain less creatine kinase activity per cell than do those from hyperplastic prostates. The BB form of creatine kinase accounts for 98% of the activity in prostatic carcinoma and in prostates without cancer. Creatine kinase has been discussed as a possible marker for prostatic carcinoma, and we had hoped that it might be useful for the assay of tumor burden. Our data suggest that, if creatine kinase is to be useful in the monitoring of tumor burden, it will be useful only in the contexts of particular patients studied longitudinally since the creatine kinase activity varies enormously among different prostatic carcinomas.