The real world based multi-cohorts study aims to evaluate the safety and effectiveness of function preserving gastrectomy including pylorus-preserving distal gastrectomy, proximal gastrectomy and wedge gastrectomy for T1 and T2 gastric cancer patients.

Gastric cancer patients with clinical stage T1/2 will be screened for the study. For the patients enrolled, a multidisciplinary discussion will be performed to evaluate the proper gastrectomy for the patients and functional preserving gastrectomy will be considered for the indicated patients. For patients not proper for functional preserving gastrectomy, standard gastrectomies will be suggested. After surgery, a close follow up will be performed. During the study, a thorough data collection will be performed to evaluate the safety and effectiveness of functional preserving gastrectomy and recovery and postoperative function of remnant stomach.

Inclusion Criteria:

• Karnofsky performance over 70%
• Histologically proven gastric or gastroesophageal joint adenocarcinoma with clinical stage T1-2N0-3M0
• No severe comorbidity with estimated survival less than 5 years

Exclusion Criteria:

• pregnancy
• Signs of distant metastases
• received chemotherapy, radiotherapy, immune therapy
• received gastrectomy
• other malignant tumors within 5 years except for cured skin cancer and cervical caner in situ.
• uncontrolled epilepsy, central nervus system disease or mental disease that affect the compliance of treatment and follow-up
• severe heart disease
• organ transplantation that needs immunosuppressor
• emergency surgery due to hemorrhage, perforation and ileus of gastric cancer

Non-advanced gastric cancer patients with the clinical stage cT1-2 that are indicated for gastrectomy