The beta-core fragment of human chorionic gonadotropin: biochemical background and clinical application

In this review an overview is given of the possible applications and usefulness of the beta-core fragment of hCG (beta cf-hCG) as an urinary tumor marker. Expression of human Chorionic Gonadotropin (hCG) is an important indicator of malignant transformation. The biochemical background of this glycoprotein hormone and the degradation pathway towards beta cf-hCG is described. There are two main pathways: peripheral degradation in the serum and the renal parenchymal degradation. HCG and its subunits show immunoreactivity and cross-reactivity with other glycoprotein hormones and their subunits. The different "in house" methods to determine beta cf-hCG developed and used by various research institutes are described. In various types of cancer, concentrations of hCG as well as its beta-subunit may be elevated, allowing the clinical use of these substances as a tumor marker. The relation between laboratory outcome and clinical status is assessed, with emphasis on the beta cf-hCG in gynecological malignancies. The limitations of the use of beta cf-hCG as a tumor marker are discussed. The stability of beta cf-hCG may allow distant follow-up in samples sent to the laboratory by mail.