High PD-L1 expression as a negative prognostic factor in stage III but not in stage II gastric cancer

Figure 1 Study flow diagram. A total of 1057 patients with gastric or gastroesophageal junction cancer (G/GEJC) were recorded in our database. Of these, 669 patients were excluded owing to the absence of a programmed death ligand-1 (PD-L1) combined positive score (CPS) assessment (n = 132), receipt of preoperative neoadjuvant therapy (n = 129), stage I or IV disease (n = 386), multiple primary malignancies (n = 1), or incomplete medical records (n = 21). The remaining 388 consecutive patients did not receive neoadjuvant therapy and were histologically confirmed as pathological stage II (pII) or pathological stage III (pIII) after gastrectomy. Among them, 159 patients were pII and 229 were pIII G/GEJC. In pII G/GEJC, 107 (67.3%) patients were PD-L1-positive (CPS ≥ 1) and 85 (53.5%) had high PD-L1 expression (CPS ≥ 5). In pIII G/GEJC, 155 (67.7%) patients were PD-L1-positive and 116 (50.7%) had high PD-L1 expression. G/GEJC: Gastric or gastroesophageal junction cancer; AJCC: American Joint Committee on Cancer; PD-L1: Programmed death ligand-1; CPS: Combined positive score; pII: Pathological stage II; pIII: Pathological stage III.

Figure 2 Survival outcomes according to programmed death ligand-1 expression status in the overall cohort of patients with locally advanced gastric or gastroesophageal junction cancer. A and B: Kaplan-Meier curves showing disease-free survival (DFS) and overall survival (OS) between programmed death ligand-1 (PD-L1)-positive and PD-L1-negative groups; C and D: Kaplan-Meier curves showing DFS and OS between high and low PD-L1 expression groups. PD-L1: Programmed death ligand-1.

Figure 3 Survival outcomes according to programmed death ligand-1 expression in patients with pathological stage II gastric or gastroesophageal junction cancer. A and B: Kaplan-Meier curves showing disease-free survival (DFS) and overall survival (OS) between programmed death ligand-1 (PD-L1)-positive and PD-L1-negative groups; C and D: Kaplan-Meier curves showing DFS and OS between high and low PD-L1 expression groups. No significant differences in DFS or OS were observed between the groups. PD-L1: Programmed death ligand-1.

Figure 4 Survival outcomes according to programmed death ligand-1 expression in patients with pathological stage III gastric or gastroesophageal junction cancer. A and B: Kaplan-Meier curves showing disease-free survival (DFS) and overall survival (OS) between programmed death ligand-1 (PD-L1)-positive and PD-L1-negative groups; C and D: Kaplan-Meier curves showing DFS and OS between high and low PD-L1 expression groups. Patients with PD-L1-positive status or high expression had significantly shorter DFS and OS than those with PD-L1-negative or low expression. PD-L1: Programmed death ligand-1.