Demonstration of an Antigen Common to Several Varieties of Neoplasia

Abstract

Abstract The serum or plasma of 674 patients was studied by means of a radioimmunoassay that detects on carcinoembryonic antigen (CEA) an antigenic site exposed at low ionic strength. Serum specimens from 11 of 299 patients hospitalized for various illnesses other than neoplastic disease had elevated levels of antigen. Subsequently, two of these patients were found to have previously undetected entodermally derived adenocarcinoma. Elevated levels of CEA were observed in serum specimens from 87 of 101 patients with known colonic adenocarcinoma, 30 of 45 patients with breast carcinoma, 26 of 35 patients with lung carcinoma and 20 of 51 patients with prostatic carcinoma. Since serum from patients with both entodermally and nonentodermally-derived carcinoma had elevated levels of CEA an antigenic site common to several tumors appears to exist on CEA.