[Creatine phosphotransferase, B subunit, as a tumor marker. Preliminary results]

Creatine kinase B (CK-B) was evaluated as a tumor marker by radioimmunoassay determination of the isoenzyme in 518 persons (control group, malignant tumors, and several other diseases). Amounts higher than 8 ng/ml (upper normal limit) was observed in 12.6 per 100 of the digestive tumors, 6.1 per 100 of the mammary tumors, 37.7 per 100 of the respiratory tumors, and 22.2 per 100 of the prostatic tumors. A relation exists between CK-B and sigmoid flexure, liver, pancreas and esophagus tumors, between CK-B and acid phosphatase in prostate tumors, and between CK-B and evolution of digestive tumor. The determination of CK-B is useful in the case of tumors lacking known tumor markers, and also as a complementary sign in the diagnosis and evolution of sigmoid flexure and prostate neoplasms.