The role of tissue and serum carcinoembryonic antigen in stages I to III of colorectal cancer—A retrospective cohort study

PURPOSE: Tissue carcinoembryonic antigen (t‐CEA) and serum carcinoembryonic antigen (s‐CEA) expression profiles are the most useful tumor markers for the diagnosis and evaluation of colorectal cancer (CRC) worldwide; however, their roles in CRC progression remain controversial. This study aimed to compare the prognostic values of both s‐CEA and t‐CEA in CRC. METHODS: A total of 517 patients from January 2006 to December 2010 with stages I‐III CRC were retrospectively examined, with 5‐year postoperative follow‐up and death as end‐points. T‐CEA expression, s‐CEA expression, and clinical pathological parameters were inputted into the SPSS 21.0 software. The Kaplan‐Meier method was used to analyze the 5‐year disease‐free survival (DFS) rate of patients in different tumor node metastasis (TNM) stages based on t‐CEA and s‐CEA expression. RESULTS: Tumor differentiation and the number of positive lymph node harvests were significantly different among the t‐CEA groups (P < 0.001, P = 0.002); however, clinicopathological features showed no significant difference. The groups with high s‐CEA and t‐CEA expression had a significantly poorer prognosis than those with low s‐CEA (P = 0.021) and t‐CEA (P < 0.01) expression, respectively. The multivariate analysis demonstrated that t‐CEA was an independent prognostic factor in CRC (P < 0.001), but s‐CEA was not (P = 0.339). The 5‐year disease‐free survival rates among the t‐CEA groups were significantly different in stages I, II, and III of CRC (P = 0.001, P < 0.001, P < 0.001), whereas in the s‐CEA groups, this difference was observed only in stage III (P = 0.014). CONCLUSION: This study shows that postoperative t‐CEA expression is an independent factor associated with poorer CRC prognosis and has a higher prognostic value than that of preoperative s‐CEA expression.