Assessment of radioimmunoassay of serum creatine kinase BB (CK-BB) as a tumor marker: studies in patients with various cancers and a comparison of CK-BB concentrations to prostate acid phosphatase concentrations.

The association between cancer and the BB isoenzyme of creatine kinase (CK-BB) was investigated, and the possibility of the role of CK-BB as a tumor marker was assessed. With the use of a specific radioimmunoassay, the concentration of CK-BB was measured in 524 sera (obtained from the National Cancer Institute-Mayo Clinic Serum Diagnostic Bank) from patients with a variety of benign and malignant disorders. In 79 of these sera, the results of radioimmunoassay for CK-BB were compared to those of three radioimmunoassays for prostate acid phosphatase. Abnormal CK-BB concentrations occurred in only about 11% of the 366 cancer patients. Some groups of cancer patients had higher rates; e.g., the CK-BB concentration was elevated in 29% of the prostate cancer patients. However, prostate acid phosphatase was abnormal in 65% of the patients with prostate carcinoma--a considerable higher fraction than that found with CK-BB. Findings in patients with benign and malignant gastrointestinal diseases indicate that CK-BB complements carcinoembryonic antigen data and might be useful as part of a tumor marker panel.