Highlights:
- 1. GEA tumors with mutations in KRAS, TP53 and RAS-MAPK pathway are associated with high PD-L1 CPS in the pMMR&MSS subgroup.
- 2. RAS-MAPK pathway alteration may be a positive predictor and TP53 mutation a negative predictor for ICI efficacy in GEA.
- 3. RAS-MAPK pathway alteration and TP53 mutation are positively and negatively, respectively, associated with tumor immunity.