The significance of creatine kinase (CKBB) in metastatic cancer of the prostate.

Alterations of serum creatine kinase isoenzymes were observed in five cases of prostatic carcinoma. Creatine kinase isoenzyme BB was found in the serum of two of three cases with metastases. Its presence in serum does not seem to be related to acid phosphatase activity but seems associated with extension of the tumor to other tissues. Preliminary studies on effusions from patients with malignant and non-malignant prostates showed that CK-BB was detectable only in cytology positive effusions. This finding suggests that CK-BB may be a tumor product rather than a result of a host response. The observation of CK-BB in a significant percentage of patients (two of three) with metastatic carcinoma of the prostate is of interest and suggests that CK-BB isoenzymes may have some predictive value in following patients with malignant disease.