Objective      To explore the diagnostic value of serum apurinic/apyrimidinic endonuclease 1 autoantibodies (APE1-AAbs) in screening colorectal cancer.       Methods      Serum APE1-AAbs of 150 patients with colorectal cancer and 170 healthy controls were detected by ELISA. Carcinoembryonic antigen (CEA)

carbohydrate antigen 19-9 (CA199) and carbohydrate antigen 242 (CA242) were detected by protein chip technology. Logistic regression and receiver operative characteristic (ROC) curve were employed for combined analysis of APE1-AAbs with CEA

CA199 or CA242.       Results      The median level of serum APE1-AAbs in the patients with colorectal cancer was 2.697

which was higher than that of the healthy controls (P0.001). With the ROC curve

area under curve (AUC) was 0.797

and the sensitivity and specificity were 62.67% and 85.29%

respectively. The AUC

diagnosis sensitivity and accuracy of colorectal cancer were increased when combining serum APE1-AAbs with CEA

CA199 or CA242.       Conclusion      Serum APE1-AAbs can help to diagnose colorectal cancer

and its combination with CEA

CA199 or CA242 can improve the early diagnosis accuracy of colorectal cancer.