ECTOPIC PRODUCTION OF CHORIONIC-GONADOTROPIN AND ITS SUBUNITS BY ISLET-CELL TUMORS - SPECIFIC MARKER FOR MALIGNANCY

Human chorionic gonadotropin (hCG) and its subunits were measured in 76 patients with islet-cell tumors. Seventeen of 27 patients with functioning islet-cell carcinomas had elevated plasma levels of hCG or 1 of its subunits (hCG-.alpha. and hCG-.beta.). Secretion was often discordant. The most frequent finding was an elevated level of hCG-.alpha. alone. In 1 patient responding to streptozocin, changes in hCG-.alpha. correlated with the clinical course. Studies of tumor extracts suggested that the markers observed in the circulation were being produced in the tumor itself. None of the 43 patients with benign disease or the 6 patients with nonfunctioning malignant tumors had elevated levels of hCG, hCG-.alpha. or hCG-.beta.. These data show that hCG and its subunits are prevalent and specific markers for islet cell carcinoma, and suggest that ectopic secretion results from malignant derepression of the genome rather than overproduction by an aberrant cell rest.