Background: The aim of the study was to assess whether preoperative carcinoembryonic antigen (CEA) level is an independent predictor of overall- and cancer-specific survival in stage I rectal cancer.
Methods: Stage I rectal cancer patients were identified in the Surveillance, Epidemiology, and End Results database between 2004 and 2011. The impact of an elevated preoperative CEA level (C1-stage) compared with a normal CEA level (C0-stage) on overall and cancer-specific survival was assessed using risk-adjusted Cox proportional hazard regression models and propensity score methods.
Results: Overall, 1932 stage I rectal cancer patients were included, of which 328 (17 %) patients had C1-stage. The 5-year overall and cancer-specific survival for patients with C0-stage were 85.7 % (95 % CI 83.2-88.2 %) and 94.7 % (95 % CI 93.1-96.3 %), versus 76.8 % (95 % CI 70.9-83.1 %) and 88.1 % (95 % CI 83.3-93.2 %) for patients with C1-stage (P < 0.001 and P = 0.001). The negative impact of C1-stage on overall and cancer-specific survival was confirmed by risk-adjusted Cox proportional hazard regression analysis (hazard ratio [HR] = 1.57, 95 % CI = 1.15-2.16, P = 0.007 and 2.04, 95 % CI = 1.25-3.33, P = 0.006), and after propensity score matching (overall survival [OS]: HR = 1.46, 95 % CI = 1.02-2.08, P = 0.044 and cancer-specific survival [CSS]: HR = 3.28, 95 % CI = 1.78-6.03, P < 0.001).
Conclusion: This is the first population-based investigation of a large cohort of exclusively stage I rectal cancer patients providing compelling evidence that elevated preoperative CEA level is a strong predictor of worse overall and cancer-specific survival.
Keywords: CEA; Carcinoembryonic antigen; Rectal cancer.