This study is for people with advanced gastric cancer (a type of cancer in the stomach). It looks at how a combination of two treatments, immunotherapy (using medicines to help your immune system fight cancer) and chemotherapy (using medicine to kill cancer cells), affects the tumor microenvironment (TME). The TME is the area around a tumor, which can influence how the cancer grows and responds to treatment. The study will compare the TME before and after treatment to understand why these treatments work for some patients but not others.
- Study includes visits before and after treatment to compare results.
- Participants will receive specific chemotherapy (S-1 plus oxaliplatin) and either nivolumab or sintilimab.
- Participants should be aged 18-70 and in good physical condition (ECOG score 0-1).
Key Points:
- Participants must not have other cancers in the last 5 years.
- No prior cancer treatments allowed.
- Participants will receive a combination of two specific treatments.