Brain-type creatine kinase BB as a potential tumour marker—Serum levels measured by radioimmunoassay in 1015 patients with histologically confirmed malignancies

Abstract

Serum CK-BB levels have been assayed in 1015 patients with histologically confirmed malignancy. Thirty-four per cent of these patients had elevated serum CK-BB levels when compared with the levels found in a population of 1006 blood donors. In breast cancer patients tumour burden correlated well with the degree of elevation of the serum CK-BB, with a mean serum level of 2.01 μ g/l (range 0.0–7.7 μ g/l) in patients post-mastectomy, rising to a mean of 4.78 μ g/l (range 0.1–37 μ g/l) in patients with metastatic disease. In carcinoma of the bronchus elevated levels occurred in 41% of patients, no correlation with apparent stage of disease being detected. In lymphomas moderate elevations of CK-BB occurred in 34% of patients and serial measurements correlated with response to therapy. Elevated levels occurred with normal ESR levels. In cancer of the bladder, prostate, testis and head and neck, raised CK-BB levels occurred more frequently in patients with metastatic disease than in those thought to have local disease alone, while in sarcoma, cancer of the ovary, uterus, cervix, stomach, bowel and anal canal the presence of persistent disease correlated with a raised CK-BB level. Radiotherapy to normal tissues containing CK-BB did not elevate serum CK-BB levels but irradiation of tumour tissue containing CK-BB (e.g. prostatic carcinoma or lymphoma) resulted in transient elevations of serum CK-BB. These results suggest CK-BB warrants further investigation as a monitor of response to therapy and as a marker of persistent or metastatic disease in a variety of tumours.