CEACAM5 and colorectal carcinoma: For diagnosis with multiple-marker combinations, CEA + CA199 + CA125 had the best diagnostic performance (AUC = 0.776, AUC = 0.650, AUC = 0.896, AUC = 0.840, AUC = 0.793) in the GC, EC, PC, GBC and CRC groups, and the sensitivity of multiple-marker combined detection was better than that of single-marker detection.