CEACAM5 and gastric tubular adenocarcinoma: PET-CT: Positron Emission Tomography-Computed Tomography, BMI: body mass index, ASA-PS: American Society of Anesthesiologists physical status, CEA: carcinoembryonic antigen, CA19-9: carbohydrate antigen 19-9, PNI: prognostic nutritional index, CAR: C-reactive protein-to-albumin ratio, SUVmax: Standardized Uptake Value Max, CD: Clavien-Dindo, tub: tubular adenocarcinoma, por: poorly differentiated adenocarcinoma, muc: mucinous adenocarcinoma