Prognostic significance of CEA levels and detection of CEA mRNA in draining venous blood in patients with colorectal cancer

Abstract

The aims of this study were to determine carcinoembryonic antigen (CEA) levels and incidence of tumor cells using the RT-PCR technique in draining venous blood of patients with colorectal cancer, correlate the results with various histopathologic factors and determine their significance as prognostic factors. From 1995 to 2000, 108 patients with adenocarcinoma of the colon or rectum, underwent curative surgery and enrolled in this prospective study. The 5-year survival group had significantly lower portal CEA levels compared to the hepatic metastasis outcome group. CEA mRNA was positive in the draining venous blood from 12 (11.1%) out of 108 patients included in the study. The rate of positive tumor cell detection in portal blood was significantly higher in the hepatic metastasis outcome group than in the 5-year survival and recurrence group. The proportion of patients with portal CEA > or =5 ng/ml was greater in patients with higher stage than in patients with lower stage. Positive CEA mRNA in draining venous blood predicted hepatic metastases and local recurrence with accuracy over 80% but with low sensitivity of 30% and 9%, respectively. Moreover, CEA level was a sensitive indicator in hepatic metastases as sensitivity was 95% and a specific indicator in predicting 5-year survival with specificity 84%.