CEA mRNA identification in peripheral blood is feasible for colorectal, but not for gastric or pancreatic cancer staging

Objective: It has been suggested that the molecular identification of cance r cells in the circulation may be useful in predicting the presence of micr ometastasis in several cancer types. The aim of the present study was there fore to assess the feasibility of CEA mRNA identification in blood for diag nosing and staging colorectal, gastric and pancreatic cancer. Methods: We s tudied 16 control subjects, 69 patients with colorectal (CRC), 30 with gast ric IGC), 27 with pancreatic cancer (PC) and 8 with benign diseases of the pancreatobiliary tree. At diagnosis CEA mRNA was identified in peripheral b lood by means of a RT-PCR procedure. Results: The specificity of this test in control subjects was 94%, and its sensitivity in identifying CRC, GC and PC were 34, 37 and 41%, respectively. False-positive findings were recorde d in 25% patients with benign diseases. No association was found between CE A mRNA and stage in patients with GC or PC. In CRC patients, positive CEA m RNA findings were correlated with local spread (chi (2) = 14.6, p < 0.01), lymph node (<chi>(2) = 18.95, p < 0.001) and distant metastasis (<chi>(2) = 11.3, p < 0.001). In these cases, CEA mRNA, but not CEA, was entered in st epwise discriminant analysis to classify the presence of lymph node metasta sis. Conclusions: The molecular detection of micrometastasis in the blood b y means of CEA mRNA identification is feasible for colorectal, but not for gastric or pancreatic cancer staging. Further studies are needed in order t o define the clinical utility of th is marker a Iso in follow-up protocols. Copyright (C) 2000 S. Karger AG, Basel.