This is the prospective, observational cohort study (G-Distress) to explore the associations of psychological stress with treatment and prognosis of gastric cancer. The participants including the patients diagnosed with gastric cancer who received surgery, chemotherapy and immune checkpoint inhibitors.

Cohort 1

Inclusion Criteria:

1. Lower age limit of research subjects 18 years old and upper age limit of 80 years old, ECOG (ECOG score standard) performance status of 0 or 1
2. Be proven to be primary adenocarcinoma of gastric cancer and staged II-III by pathological evidences
3. R0 gastrectomy with D2 lymphadenectomy
4. Receiving adjuvant chemotherapy

Exclusion Criteria:

1. History of chemotherapy, radiotherapy, immunotherapy or target therapy
2. Multiple primary tumors
3. Suffering from other serious diseases, including cardiovascular, respiratory, kidney, or liver disease, complicated by poorly controlled hypertension, diabetes, mental disorders or diseases
4. Unavailable for R0 resection and D2 lymph node dissection.
5. Patients with stage IV gastric cancer

Cohort 2

Inclusion Criteria:

1. Lower age limit of research subjects 18 years old and upper age limit of 80 years old, ECOG (ECOG score standard) performance status of 0 or 1
2. Be proven to be primary adenocarcinoma of gastric cancer and staged III-IV by pathological evidences
3. Receiving gastrectomy
4. Receiving preoperative chemotherapy

Exclusion Criteria:

1. Unavailable for chemotherapy, radiotherapy, immunotherapy or target therapy
2. Multiple primary tumors
3. Suffering from other serious diseases, including cardiovascular, respiratory, kidney, or liver disease, complicated by poorly controlled hypertension, diabetes, mental disorders or diseases
4. Unavailable for gastrectomy

Cohort 2

Inclusion Criteria:

1. Lower age limit of research subjects 18 years old and upper age limit of 80 years old, ECOG (ECOG score standard) performance status of 0 or 1
2. Be proven to be primary adenocarcinoma of gastric cancer and staged IV by pathological evidences
3. Unavailable for gastrectomy
4. Presence of at least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors version 1.1

Exclusion Criteria:

1. Unavailable for chemotherapy, radiotherapy, immunotherapy or target therapy
2. Multiple primary tumors
3. Suffering from other serious diseases, including cardiovascular, respiratory, kidney, or liver disease, complicated by poorly controlled hypertension, diabetes, mental disorders or diseases

gastric cancer patients