The correlation between gastrointestinal tumors pathological parameters and the evaluated CEA,CA199,CA125 and CA724 was also assessed.The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic efficacy of the markers alone and in combination and to explore their predictive value in diagnosing gastrointestinal tumors. This evidence concerns the gene CEACAM5 and digestive system neoplasm.