Serum-SP1-pregnancy-specific-beta-glycoprotein in choriocarcinoma and other neoplastic disease

A radioimmunoassay for a plancental glycoprotein, beta1SP1, capable of detecting 2 microgram/l of the glycoprotein in serum was used to measure concentrations of beta1,SP1 in patients with choriocarcinoma, teratoma, colonic cancer, breast cancer, and ovarian cancer. 12 out of 94 (13%) healthy men and health non-pregnant women had detectable serum-beta1SP1 concentrations. Concentrations up to 50 000 microgram/l were found in the sera of patients with hydatidiform mole, invasive mole, choriocarcinoma, and malignant teratoma. beta1-glycoprotein concentrations were generally much lower than corresponding concentrations of chorionic gonadotrophin which is the most reliable marker for trophoblastic tumours. In a few cases, however, beta1-glycoprotein measurements may be useful in the detection of minimal residual tumour. The slightly raised values found in some patients with carcinoma of the colon, breast, or ovary seem unlikely to be useful for diagnostic purposes of for monitoring the course of these cancers.