CEACAM5 and colorectal cancer: The significance of GPS has been verified by several groups30 and has been reported to be superior to blood-tumor markers like carcino-embryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) in colorectal cancer.31 In concordance to this the herein reported PER score also classified patients into 3 different groups based on preoperative risk assessment.