Serum CEA and CA 19-9 levels are associated with the presence and severity of colorectal neoplasia

Purpose: Limited data are available regarding the association between circulating serum carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9 (CA 19-9) concentrations and colorectal adenoma. We aimed to investigate whether elevated serum CEA and CA 19-9 levels are correlated with the presence of colorectal neoplasia (CRN) and whether the levels of these antigens vary according to CRN severity. Materials and Methods: A cross-sectional study was performed on asymptomatic subjects who underwent colonoscopy between 2010 and 2014 as part of a comprehensive health screening program in Korea. Results: A total of 124509 participants with measured serum CEA levels and 115833 participants with measured serum CA 19-9 levels were analyzed. Elevated CEA concentrations were associated with a higher rate of any adenoma, advanced adenoma, high-risk adenoma, advanced CRN (ACRN), overall CRN, and colorectal cancer (CRC). Elevated CA 19-9 concentrations were also associated with a higher rate of advanced adenoma, high-risk adenoma, ACRN, and CRC. Both elevated levels of CEA and CA 19-9 were identified as independent predictors of ACRN. Among patients with CRN, the proportions of elevated CEA/CA 19-9 levels were significantly higher in patients with ACRN than in those with non-ACRN, and these levels were correlated with larger lesion size and multiplicity of adenomas. Conclusion: Both elevated serum CEA and CA 19-9 levels were associated with the presence of ACRN, as well as CRC. Elevated CEA levels were also associated with the presence of overall CRN. Moreover, both CEA and CA 19-9 levels were correlated with the severity of CRN.