Objectives: Carcinoembryonic antigen (CEA) is a reliable tumor marker for the management and surveillance of colon cancer. However, limitations in previous studies have made it difficult to elucidate whether CEA should be established as a prognostic indicator. This study examines the association between elevated preoperative CEA levels and overall survival in colon cancer patients using a national population-based registry.
Methods: Stage I-III colon cancer patients were identified from the 2004-2006 National Cancer Database. A multivariable Cox proportional hazards model was used to estimate the association between elevated CEA levels and overall survival after controlling for important patient, hospital, and tumor characteristics. A Monte Carlo Markov Chain was used to impute the large degree of missing CEA data. All models controlled for the propensity score in order to account for selection bias.
Results: A total of 137,381 patients met the inclusion criteria. Overall, 34 % of patients had an elevated CEA level and 66 % had a normal CEA level, with a median survival of 70 and 100 months, respectively. Patients with an elevated CEA level had a 62 % increase in the hazard of death (HR 1.62, 95 % CI 1.53-1.74) compared with patients with a normal CEA level.
Conclusions: Preoperative CEA was an independent predictor of overall survival across all stages. The results support recommendations to include CEA levels as another high-risk feature that clinicians can use to counsel patients on adjuvant chemotherapy, especially for stage II patients.