Table 2. Summary of study and patient characteristics including prognostic factors.

TSS, total sample size; HR, hazard ratio; OR, odds ratio; LN, lymph node; NA, not available; PD-L1(+): PD-L1 presence/expression/positivity.

*OS is described as five-year survival and TNM stage (III-IV vs I-II) as TNM stage (low vs high).

Note: The study population includes those diagnosed with GC (Stage I-IV).

Table credit: Gashaw Hassen, Nidhi Jain, and Amita Kasar. 

Study and patient characteristics of the three meta-analyses included in the umbrella review					Outcomes/effect measures in PD-L1(+)
					OS	Clinicopathological characteristics
						LN metastasis	TNM stage (III-IV vs I-II)
					HR (95% CI)	OR (95% CI)	OR (95% CI)
Study author & publication year	Study period (14 years)	TSS (8419)	Male (%)	PD-L1(+) (%)
Zhang et al., 2016 [18]	2006-2016	1901	38.9	39.5	1.64 (1.11-2.43)	2.17 (1.04-4.52)	2.36 (0.83-6.69)
Gu et al., 2017 [19]	2006-2017	3291	32.9	38.2	1.46 (1.08-1.98)	0.54 (0.31-0.95)	0.72 (0.40-1.28)
Qiu and Du, 2021 [20]*	2014-2019	3227	NA	39.9	1.39 (1.14-1.69)	1.73 (1.18-2.54)	1.28 (0.81-2.02)