Human Chorionic Gonadotropin Immunoreactivity in Serum of Patients With Malignant Neoplasms

ABSTRACT: The beta-human chorionic gonadotropin (HCG) radioimmunoassay was used to determine the presence of HCG immunoreactivity in serum of patients (n = 71) with diagnosis of cancer. Of patients with active neoplasia, 60.5% showed HCG immunoactivity above controls (>> 5 mlU/ml). An apparent degree of correlation was observed with tumor activity in that a case with widespread metastases due to a colonic carcinoma exhibited the highest HCG levels while, in one patient, the level of HCG decreased progressively according to therapeutic response. A high frequency of immunoactive HCG was found in patients with carcinomas of the cervix, breast, gonad digestive system and in patients with melanoma. Trophoblastic cells were not evident in the tumors biopsied. Immunologic similarity of HCG secreted by tumors and that contained in serum of pregnant women, of patients with hydatidiform mole of males injected with exogenous HCG was shown by parallel inhibition curves in the radioimmunoassay. The positivity of HCG was predominant in cases of cervix carcinoma.