Prognostic value of the postoperative carcinoembryonic antigen level in colorectal cancer: A meta-analysis.

Background: Carcinoembryonic antigen (CEA) is one of the commonly used preoperative biomarkers for colorectal cancer (CRC), but no meta-analysis has evaluated the findings of all recently published studies to determine whether its postoperative level can serve as a prognostic indicator.

Methods: We conducted a systematic search for eligible literature from the PubMed, EMBASE, and Web of Science databases in October 2023. Studies that investigated the relationship between postoperative serum CEA levels and prognosis in CRC patients were included. Outcome indicators, including overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS)/recurrence-free survival (RFS), were analyzed using a fixed-effects or random-effects model. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used as effective values.

Results: This meta-analysis included 20 eligible studies involving 10,114 CRC patients from the East Asian and Western countries. A comprehensive analysis revealed that elevated postoperative CEA levels were associated with low OS (HR: 2.92, 95% CI: 2.36-3.62, and p < 0.000), DFS (HR: 2.81, 95% CI: 2.01-3.94, and p < 0.000), and RFS/PFS (HR: 2.52, 95% CI: 1.75-3.62, p < 0.000). A subgroup analysis by region, analysis type, distant metastasis, HR obtain method, sample size, postoperative measurement date, and study design demonstrated that the negative correlation observed between high serum CEA levels after surgery and poor prognosis was not significantly different between the subgroups.

Conclusion: When CEA levels are found to be elevated during postoperative follow-up, more active intervention measures should be implemented to further improve the patient's survival outcomes.