Serum carcinoembryonic antigen to predict recurrence in the follow-up of patients with colorectal cancer

Abstract

Introduction: Serum carcinoembryonic (CEA) antigen is used as a diagnostic screening tool during follow-up in colorectal cancer patients. However, it remains unclear whether preoperative serum CEA is a reliable marker in the follow-up to predict recurrence. The aim of the study is to determine the value of elevated pre-and postoperative serum carcinoembryonic antigen levels (CEA > 5 µg/L) as an independent prognostic factor for locoregional and distant recurrence in patients who underwent curative surgery for colorectal cancer. Methods: This single center retrospective observational cohort study includes patients who underwent curative surgery for colorectal cancer between 2005 and 2015 and had pre-and postoperative serum CEA measurements. Five-year disease-free survival and multivariate Cox regression analyses were performed to adjust for confounding factors. Results: Preoperative serum CEA level was measured in 2093 patients with colorectal cancer. No significant association was found between an elevated preoperative serum CEA and locoregional recurrence (adjusted hazard ratio (HR) 1.29 (95% confidence interval (CI) 0.91, 1.84; P=0.26)). However, a significant association was found between an elevated preoperative serum CEA and systemic recurrence (adjusted HR 1.58 (95% CI 1.25, 2.00; P<0.01)]. The five-year disease-free survival was lower in patients with elevated preoperative serum CEA levels (P<0.01). Postoperative serum CEA level was the most sensitive for hepatic metastases during follow-up (73.3%). Conclusions: The preoperative serum CEA level is an independent prognostic factor for systemic metastasis after curative surgery for colorectal cancer in patients with stage I–III disease. The level is the most sensitive for hepatic metastasis compared to metastasis to other anatomic sites.