Objective: Evaluating the prognostic significance of carcinoembryonic antigen (CEA) for colorectal cancer (CRC) patients in new cutoffs.
Patients: Three hundred and seventy cases and 1164 cases of CRC patients receiving tumor resection from hospitals of Sun Yat-sen University were retrospectively investigated as training cohort and validation cohort respectively. CEA was categorized into quintiles for Kaplan-Meier analysis and Cox proportional hazards regression analysis.
Results: CEA was categorized into quintiles with the cutoff points of (0-1.5) ng/ml, (1.5-2.3) ng/ml, (2.3-3.98) ng/ml, (3.98-8.02) ng/ml, (8.02-Maximum) ng/ml. In CRC patients from training cohort, progressively worse outcomes were observed in each increasing quintile of CEA in term of overall survival (Log-rank Test: P< 0.0001, Log-rank Test for Trend: P< 0.0001) and progression free survival (Log-rank Test: P= 0.0002, Log-rank Test for Trend: P< 0.0001). CEA quintile was associated with overall survival (HR: 1.209, 95%CI: 1.033-1.416, P= 0.018) and progression free survival (HR: 1.195, 95%CI: 1.024-1.394, P= 0.024). Validation analysis also showed that patients with increasing CEA quintile suffered unfavorable overall survival (Log-rank Test: P= 0.0001, Log-rank Test for Trend: P= 0.0001) and progression free survival (Log-rank Test: P= 0.0001, Log-rank Test for Trend: P= 0.0001). CEA quintile was associated with overall survival (HR: 1.330, 95%CI: 1.123-1.576, P< 0.001) and progression free survival (HR: 1.218, 95%CI: 1.089-1.362, P= 0.001).
Conclusions: Preoperative CEA quintile was an independent predictor of unfavorable prognosis in CRC patients. Even within normal range, CEA quintile might still impact prognosis outcomes of CRC.
Keywords: Colorectal cancer; carcinoembryonic antigen; prognosis.