Abstract
Concentrations of creatine kinase isoenzymes (CK-MM, CK-MB, CK-BB) in tumor tissues and in sera of patients with various lung carcinomas were determined by use of a sensitive enzyme immunoassay method. Although the CK-BB levels were increased in the tissue of small cell carcinoma of the lung, the CK-MM, CK-MB levels were not increased in the tissue of any lung carcinoma. The average tissue contents of CK-BB in small cell carcinoma (SCCL), adenocarcinoma (ADCL), squamous cell carcinoma (ECCL), other carcinoma (OTCL) of the lung, and normal lung were 2000, 95, 85, 110, 100, ng/mg, respectively. The serum CK-BB levels were enhanced in all types of lung carcinoma examined, but the serum CK-MM and CK-MB levels were not enhanced in any type of lung carcinoma. The mean values and standard deviations of serum CK-BB were 2.65±3.44ng/ml in SCCL, 1.09±0.95ng/ml in ADCL, 1.20±1.10ng/ml in ECCL, 1.04±1.60ng/ml in O TCL. The serum CK-BB concentrations of healthy adults were estimated to be 0.32±0.14 (mean±SD) ng/ml, ranging from 0.11 to 0.68ng/ml. When the values above 1.0ng/ml were tentatively considered abnormal, abnormally elevated cases were seen in 28/40 (70%) of patients with SCCL, 25/67 (37%) with ADCL, 21/51 (41%) with ECCL, 4/11 (36%) with OTCL. Since serum CK-BB concentrations in patients with lung cancer changed in parallel with the clinical course, serum CK-BB may be an useful biomarker for monitoring the clinical course of patients with lung cancer, especially in SCCL.
