This is a single-center, retrospective, observational, real-world study. We collected general and clinical data of patients with advanced gastric cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2018 to July 2024.

All patients received combination therapy with ICIs inhibitors for at least 2 cycles in the first-line and at least 2 cycles of ICI inhibitor-based therapy in the second-line after first-line progression. The efficacy and safety of treatment were evaluated, including overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), Pattern of immune progression after cross-line therapy, grade 3-5 treatment-related adverse events (TRAEs), and immune-related adverse events (irAEs). Cox regression model was used to investigate the influence of multiple factors on survival.

Inclusion Criteria:

• Histologically confirmed metastatic or advanced GC/GEJC;
• Received at least 2 cycles of anti-PD-1 or PD-L1 based therapy in the first-line setting;
• Receiving at least 2 cycles of ICI-based second-line therapy;
• ECOG PS 0 or 1;
• Radiographic response was also assessed during treatment and survival.

Exclusion Criteria:

• patients had other malignancies within the past 5 years;
• lack of survival and clinical efficacy data;
• combined radiotherapy regimens in the second-line treatment.

All patients received combination therapy with ICIs inhibitors for at least 2 cycles in the first-line and at least 2 cycles of ICI inhibitor-based therapy in the second-line after first-line progression.