CEA and NCA levels in peripheral and tumour venous blood of patients with gastric and colonic carcinomas estimated by RIA and EIA methods.

Carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) levels in draining tumour blood were compared with concentrations of these antigens in peripheral blood of patients with gastric and colonic malignancies. The controls were cases with gastric and duodenal ulcers. The results obtained by radioimmunoassay (RIA) were compared with enzyme immunoassay (EIA). It was shown that patients with high CEA levels in draining tumour blood also had elevated values of this antigen in peripheral blood, but that the CEA values in blood flowing from tumours were usually higher than in peripheral blood. CEA concentrations in tumour venous blood and in peripheral blood depended on clinical advancement and neoplastic venous invasion. NCA determination had no significance in clinical monitoring of studied neoplasms. CEA level determinations performed by the RIA using CEA standard prepared in our laboratory and assays with use of Abbott CEA-EIA kit gave fully comparable results.