While the majority of patients in this patient collective with CRC in UICC stage I and II had both preoperative tumor markers below the cut-off value (UICC stage I + II: 72%), patients diagnosed with higher tumor stages had either only the tumor marker CEA (UICC stage IV: 32%) or both tumor markers (UICC stage IV: 42%) increased. Here, CEACAM5 is linked to colorectal carcinoma.