Few molecules have created so much
confusion as the hCG series of molecules. Here we present a comprehensive review of hCG as a
tumor marker, of hCG and
cancer and modern perspectives on the multiplicity of hCG, and its appropriate use in the management of gynecological
malignancies and
gestational trophoblastic diseases. The complexity of hCG is better understood. There is regular hCG produced by syncytiotrophoblast cells in pregnancy and by
hydatidiform moles. This
hormone functions to advance uterine angiogenesis and promote
progesterone production by corpus luteal cells. Hyperglycosylated hCG is an independent molecule to regular hCG, it varies significantly from hCG in structure and is produced by cytotrophoblast cells. It is an autocrine or
cytokine which functions to promote growth, invasion and
malignancy. It is an absolute marker of
invasive mole and invasive
choriocarcinoma. Hyperglycosylated hCG is invaluable in the diagnosis and management of
gestational trophoblastic diseases. The free beta-subunit of hCG is also an autocrine or
cytokine and is produced in most gynecologic
malignancies. Serum free beta-subunit or its urinary degradation product beta-
core fragment is produced by 68% of ovarian, 51% of endometrial and 46% of cervical
malignancies. Free beta-subunit enhances growth and invasion in all these
malignancies leading to poor prognosis. Free beta-subunit and beta-
core fragment are good
tumor markers for these
malignancies. There are few circumstances that create more
confusion than the patient presenting with persistent low positive hCG results in the absence of pregnancy and absence of obvious
malignancies. The series of hCG molecules as
tumor markers will be reviewed to help the clinician best diagnose these often difficult clinical problems.