No significant differences were found between the groups regarding baseline characteristics, such as sex, age, American Society of Anaesthesiologists (ASA) score, preoperative carcinoembryonic antigen (CEA) level, preoperative CA19-9 level, distance from the anal verge, interval time between NCRT and surgery, pre-NCRT cT stage, pre-NCRT cN stage, hypoproteinemia, estimated blood loss, operative time, postoperative hospital stay, organ preservation, tumor size, BMI level, and anemia (all P > 0.05, Tables 1, 2). This evidence concerns the gene CEACAM5 and anemia.