Table 1.

Prognostic significance of PD-L1 expression in gastric and esophageal cancer.

Author	Number of Patients	Type of Cancer	Histology	Disease Stage	Percentage of PD-L1+	Prognosis (PD-L1+)	Prognostic Value	Reference
Böger C et al.	465	gastric cancer	adenocarcinoma	all stages	tumor cells: 30.1% (primary cancer), 60% (liver metastases) immune cells: 88.4% (primary cancer), 73.3% (liver metastases)	better	improved OS and tumor specific survival	[12]
Pereira MA et al.	287	gastric cancer	adenocarcinoma	all stages	8.8%	no impact	no impact	[13]
Tamura T et al.	431	gastric cancer	adenocarcinoma	all stages	29.6%	worse	worse OS for stage II/III	[14]
Zhang L et al.	132	gastric cancer	adenocarcinoma	II/III	50.8%	worse	worse OS	[15]
Eto S et al.	105	gastric cancer	adenocarcinoma	II/III	24.7%	worse	worse OS (statistically non-significant)	[16]
Tsutsumi et al.	90	esophageal cancer	SCC	localized	36.6%	worse	worse OS and relapse free survival	[17]
Kim R et al.	200	esophageal cancer	SCC	localized	33.5%	worse	worse locoregional relapse rate and distant metastasis rate, no change in OS	[18]
Zhang W et al.	344	esophageal cancer	SCC	II/III	tumor cells 14.5%, immune cells 24.7%	better	better OS and DFS only in immune cells PD-L1+	[19]
Zhu Y et al.	133	esophageal cancer	SCC	pT3pN0M0	42.1%	worse	worse DFS and OS	[20]
Jiang Y et al.	428	esophageal cancer	SCC	localized and metastatic	79.7%	worse	worse DFS and OS in radically treated patients	[21]
Jesinghaus M et al.	125	esophageal cancer	SCC	all stages	71% tumor cells, immune cells 87%	better	better OS, DSS and DFS (PD-L1+ tumor cells)	[22]
Chen MF et al.	162	esophageal cancer	SCC	not specified	45.7%	worse	worse treatment response and OS	[23]
Kawazoe A et al.	487	gastric cancer	adenocarcinoma	localized	tumor cells 22.8%, immune cells 61.4	no impact	no impact	[24]
Thompson ED et al.	34	gastric cancer	adenocarcinoma	localized	tumor cells 12%, immune cells 44%	worse	worse PFS and OS	[25]
Yang JH et al.	72	gastric cancer	adenocarcinoma	IV	58.3%	better	better PFS	[26]
Seo AN et al.	116	gastric cancer	adenocarcinoma	localized	tumor cells 49.1%, stromal cells 56.9%	worse	worse DFS, not OS	[27]
Ito S et al.	90	esophageal cancer	SCC	localized	19%	worse	worse OS	[28]
Hsieh CC et al.	150	esophageal cancer	SCC	localized	64%	worse	worse DFS	[29]
Kollmann D et al.	168	esophageal cancer	adenocarcinoma	localized	tumor cells 43.5%, immune cells 69%	better	tumor cells expression - better DFS	[30]
Tanaka K et al.	180	esophageal cancer	SCC	localized	29.4%	worse	worse OS for patients after neoadjuvant chemotherapy	[31]
Li Z et al.	137	gastric cancer	adenocarcinoma	all stages	40.9%	worse	worse OS	[32]
Wang L et al.	550	gastric cancer	adenocarcinoma	all stages	37.3%	no impact	not associated	[33]
Saito R et al.	96	gastric cancer	adenocarcinoma	not specified	tumor cells 34%, stromal cells 45%	worse	worse OS and DSS	[34]
Cho J et al.	78	gastric cancer	adenocarcinoma	all stages	9% tumor cells, 60.3% immune cells	better	better OS (immune cells PD-L1+)	[35]
Ma C et al.	44	gastric cancer	adenocarcinoma	all stages	72%	no impact	not associated	[36]
Koh J et al.	392	gastric cancer	adenocarcinoma	II/III	25%	no impact	not associated	[37]

SCC: squamous cell cancer, OS: overall survival, DFS: disease free survival, PFS: progression free survival, DSS: disease-specific survival.