Establishment of Serum Proteomics Subtypes of Gastric Cancer and Its Clinical Application

Inclusion criteria

• Male or female, aged 18 and ≤ 75 years old.
• KPS score ≥ 80 points within 7 days prior to enrollment.
• Histologically confirmed gastric adenocarcinoma at initial diagnosis.
• Tumor located in the proximal stomach, including the gastroesophageal junction (defined as within 5cm proximal and distal to the cardia), gastric fundus, and upper body of the stomach.
• Clinical staging based on endoscopic ultrasound or enhanced CT/MRI examination, staged as cT3~4aN+M0 (according to the 8th edition of AJCC TNM).
• Presence of at least one evaluable lesion according to RECIST 1.1 criteria on abdominal CT/MRI examination.
• Surgeon participating in this study determines that curative surgical resection is feasible.
• Major organ function is able to tolerate neoadjuvant therapy.
• No accompanying diseases that significantly reduce survival expectancy to < 5 years.
• Willingness and ability to comply with the study protocol during the study period.
• Provide written informed consent prior to entering the study, and the patient understands that they can withdraw from the study at any time without any loss.

Exclusion criteria

• Patients with signs of distant metastasis or local unresectable factors.
• Patients with imaging or endoscopic ultrasound suggesting T1 or T2 disease.
• Patients who have received cytotoxic chemotherapy, radiotherapy, immunotherapy, or curative surgery for gastric cancer, excluding corticosteroids.
• Patients who have experienced gastrointestinal bleeding within the two weeks prior to enrollment or are judged by the investigator to be at high risk of bleeding.
• Patients with upper gastrointestinal obstruction, physiological dysfunction, or malabsorption syndrome that may affect oral drug absorption.
• Patients who have received live vaccines within 4 weeks prior to enrollment. (Note: Seasonal influenza vaccines, which are usually inactivated vaccines, are allowed. Vaccines administered intranasally are live vaccines and are not allowed.)
• Patients who have received immunotherapy (such as interleukins, interferons, thymosin, etc.) or any investigational treatment within 28 days prior to enrollment or within 5 half-lives (whichever is shorter, but at least 14 days).
• Patients who have undergone major surgery within 28 days prior to enrollment, unless the surgery was minimally invasive (e.g., peripherally inserted central catheter [PICC] via peripheral venous puncture).
• Uncontrolled systemic diseases.