Comparing the age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA), smoking status, underlying diseases, etc, there were no significant differences in other indicators except for significant differences in age; comparison between preoperative blood routine, blood biochemistry, coagulation, tumor markers, lung function, lower extremity venous ultrasound, preoperative carcinoembryonic antigen (CEA) levels, preoperative D-dimer levels, there were significant differences in lung function and lower extremity intermuscular vein expansion ratio. Here, CEACAM5 is linked to neoplasm.