Clinical validity of tissue carcinoembryonic antigen expression as ancillary to serum carcinoembryonic antigen concentration in patients curatively resected for colorectal cancer

Abstract

Although serum carcinoembryonic antigen (CEA) level is prognostic in colorectal cancer, the prognostic role of tumour CEA expression is unclear. The aim of this study is to identify the prognostic and surveillance roles of tissue CEA expression along with serum CEA concentration in patients curatively resected for colorectal cancer. Between January and December 2003, 294 patients who underwent curative resection for colorectal cancer were included in the study. Correlation of tissue CEA expression with overall survival (OS), disease-free survival (DFS) and elevated serum CEA concentration at tumour recurrence were analysed. Tissue CEA expression was positive in 215 patients (73.1%). CEA expression was an independent prognostic factor for OS [hazard ratio (HR) = 2.537, 95% confidence interval (CI) = 1.065-6.042, P = 0.035] and DFS (HR = 3.090, 95% CI = 1.405-6.795, P = 0.005). Elevation of serum CEA at tumour recurrence was significantly lower in patients without than with tissue CEA expression (14.3 vs 57.6%, P = 0.045). Moreover, when patients were grouped according to a combination of serum CEA elevation and tissue CEA expression, those with tissue CEA expression and elevated serum CEA (group 3) had significantly poorer OS and DFS (P < 0.001 each) than those without CEA expression and elevated serum CEA (group 1) and those with either tissue CEA expression or elevated serum CEA (group 2). OS (P = 0.006) and DFS (P = 0.027) were both significantly greater in group 1 than in group 2. Tissue CEA expression is a prognostic factor in patients with colorectal cancer. Analysis of tissue CEA expression may be helpful in determining the clinical utility of serial measurements of serum CEA as surveillance in patients with curatively resected colorectal cancer.