Using univariate analysis, we found that older age (P = 0.004), tumor location at rectum (P = 0.048), larger tumor size (P < 0.001), lower BMI (P = 0.001), lower pre-operative serum albumin level (P < 0.001), poorly differentiated histology (P < 0.001), advanced AJCC/UICC stage (P < 0.001), higher pre-operative and post-operative serum CEA levels (both P < 0.001), presence of vascular invasion (P < 0.001) and perineural invasion (P < 0.001) were statistically significant poor prognostic factors of OS. The gene discussed is CEACAM5; the disease is neoplasm.