The serum level of midkine, a heparin-binding growth factor, as a tumor marker

Abstract

Midkine (MK) is a heparin-binding growth factor distinct from fibroblast growth factors. Serum levels of MK were determined by enzyme-linked immunoassay using affinity-purified anti-human MK antibody. Elevated levels of MK were frequently observed in sera from patients with various carcinomas including lung carcinoma, bile duct carcinoma, colon carcinoma and esophageal carcinoma. Most patients with lung carcinoma showed high MK serum values. In colorectal carcinoma, some correlation was observed between high MK value and tumor invasion. Surgical removal of carcinomas invariably resulted in decreases in the MK level. Determination of serum MK may be useful as an aid in initial screening of certain carcinomas, such as lung carcinoma.