Preoperative serum carcinoembryonic antigen elevation in stage I colon cancer: improved risk of mortality in stage T1 than in stage T2

PurposeThis study aimed to investigate the implications of preoperative serum carcinoembryonic antigen (CEA) elevation in cause-specific survival (CSS) of patients diagnosed with stage I (T1N0M0 and T2N0M0) colon cancer.MethodsEligible patients diagnosed with stage I colon cancer from the Surveillance, Epidemiology, and End Results (SEER) database from January 2004 to December 2010 were included in this respective and propensity score-matched (PSM) study. Some Cox proportional hazards models were constructed to identify prognostic factors associated with oncologic outcomes of colon cancer. Pearson's chi-squared tests and Kaplan-Meier methods were performed.ResultsThe median follow-up time of the whole cohort was 79months. A total of 16,659 patients diagnosed with stage I colon cancer were identified from the SEER database. Multivariate Cox analyses showed that stage T1N0M0 in the context of serum CEA elevation (T1, CEA+) presented up to 158.4% increased risk of colon cancer-specific mortality compared with stage T1N0M0 in the context of normal serum CEA [hazard ratio (HR)=2.584, 95% confidence interval (CI)=2.167-3.082, P<0.001]. After PSM, Kaplan-Meier survival curves of stage T1N0M0 colon cancer showed that 5-year CSS rates of normal and elevated CEA were 94.8% and 96.6% (P<0.001).ConclusionsThis large population-based and propensity score-matched study with long follow-up time provides the first evidence that stage T1N0M0 colon cancer with the elevation of preoperative serum CEA would be a surrogate of aggressive tumor biology and predict poor prognosis. In addition, this subgroup of colon cancer might need to be paid more attention of clinicians.