Background: Preoperative carcinoembryonic antigen (CEA) has yet to be used as a prognostic or adjuvant chemotherapy factor for colorectal cancer (CRC).
Methods: This retrospective cohort study included all stage I-III CRC patients with different preoperative serum CEA levels (≤ 5, 5-10, and > 10 ng/ml) at a single center between 1995 and 2010. Propensity score matching was performed in a 1:1 ratio between the two elevated CEA groups (5-10 ng/ml and > 10 ng/ml) and in a 1:2 ratio between the elevated and non-elevated groups (≤ 5 ng/ml), with a caliper of 0.05.
Results: After exclusion and matching, 3857 patients had preoperative CEA levels ≤ 5 ng/ml, 1121 patients had CEA levels between 5 and 10 ng/ml, and 1121 patients had CEA levels > 10 ng/ml. Elevated preoperative CEA showed an increased risk of overall survival (5-10 ng/ml: hazard ratio [HR] 1.376; > 10 ng/ml: HR 1.523; both p < 0.001), cancer-specific survival (5-10 ng/ml: HR 1.404; > 10 ng/ml: HR 1.712; both p < 0.001), and recurrence free interval (5-10 ng/ml: HR 1.190; > 10 ng/ml: HR 1.468; both p < 0.05). Patients with negative lymph node staging (LNs) and CEA > 10 ng/ml, as well as those with positive LNs and CEA ≤ 5 ng/ml, showed similar overall survival (5-year survival: 72% vs. 69%; p = 0.542) and recurrence free intervals (19.9 vs. 21.72 months; p = 0.662).
Conclusions: A preoperative CEA level can be an independent prognostic factor for stage I-III CRC after curative resection. Patients with negative LNs and preoperative CEA level > 10 ng/ml should be considered for intensive follow-up or adjuvant chemotherapy.