IDENTIFICATION OF CARCINOEMBRYONIC ANTIGEN MESSENGER-RNA IN CIRCULATING PERIPHERAL-BLOOD OF PANCREATIC-CARCINOMA AND GASTRIC-CARCINOMA PATIENTS

To detect adenocarcinoma cells in the circulating peripheral blood, we analyzed the presence of carcinoembryonic antigen (CEA) mRNA in the p eripheral blood obtained from patients with pancreatic carcinoma (PC) or with gastric carcinoma (GC) and also, as controls, from pancreatiti s or gastritis patients without carcinomas, a gastric lymphoma patient and four healthy volunteers. Because of the small number of carcinoma cells expected in the peripheral blood, the analysis was performed by the reverse transcription followed by an original two-step polymerase chain reaction. By this sensitive method, 3 of 9 PC patients and 2 of 9 GC patients were positive for CEA mRNA. Except for 1 highly advance d PC patient, 3 of 4 CEA mRNA-positive patients developed recurrence a fter curative resection or liver metastasis after palliative operation within 9 months after the analysis. None of the control patients was positive for CEA mRNA in the peripheral blood. The results suggest tha t our sensitive RT-PCR method for detecting CEA mRNA in the peripheral blood is practically useful to find the hematogenous spreading of ade nocarcinoma cells.