The expression of subunits of human chorionic gonadotropin (hCG) by nontrophoblastic, nonendocrine, and endocrine tumors.

The value of the subunits of human chorionic gonadotropin (hCG) as tumor markers is controversial. The production of hCG-alpha and hCG-beta by 214 nontrophoblastic exocrine and by 416 endocrine tumors was analyzed by using immunocytochemical technics. hCG-alpha immunoreactivity was found in 131 of 416 endocrine and in 8 of 214 nonendocrine tumors. hCG-beta could not be visualized specifically with the use of two polyclonal antisera and one monoclonal antibody. The authors conclude that (1) hCG-alpha is neither a tissue nor a tumor-specific marker; (2) hCG-alpha is produced by a variable proportion (21-55%) of endocrine tumors arising in various organs but not by ileal carcinoids, paragangliomas, pheochromocytomas, nor Merkel cell tumors; (3) hCG-alpha is a marker of malignancy only in pancreatic endocrine tumors; and (4) hCG-beta is rarely, if ever, produced by tumors.