Plasma beta-subunit human chorionic gonadotropin assay in molar pregnancy and choriocarcinoma.

Serum plasma levels of the beta-subunit of human chorionic gonadotropin (HCG-beta) were measured by radioimmunoassay in 24 women with molar pregnancies and five with choriocarcinoma. In the patients with molar pregnancy, plasma HCG-beta concentrations became undetectable within 8 to 173 days. In the patients with choriocarcinoma, plasma HCG-beta levels declined rapidly with appropriate chemotherapy. Serial plasma HCG-beta assay in this series accurately determined remission and detected early recurrences during follow-up. All patients are in remission with a mean follow-up of 22 months for the patients with choriocarcinoma.