. 2020 Mar 24;63(3):346–356. doi: 10.5468/ogs.2020.63.3.346

Table 1. Clinical characteristics of cohorts in the studies included in our meta-analysis.

Study	Country	Dates of diagnosed	Median age	Study type	Sample	Histology	PD-L1 cut-point	Grade	Stage	No. of patients	PD-L1 positive	PD-L1 negative	Follow-up duration	Overall survival rate				Progression-free survival rate
Study	Country	Dates of diagnosed	Median age	Study type	Sample	Histology	PD-L1 cut-point	Grade	Stage	No. of patients	PD-L1 positive	PD-L1 negative	Follow-up duration	HR	95% CI	P-value	Standard error	HR	95% CI	P-value	Standard error
Hamanishi et al., 2007 [5]	Japan	1993–2001	55 (26–78)	Retrospective study	Tissue	Serous, clear cell, endometrioid, mucinous, and other types	IHC score's median level		I–IV	70	48	22	5.19 yr	4.26	1.39–12.94	0.011	0.248	2.57	1.11–5.93	0.027	0.186
Darb-Esfahani et al., 2016 [14]	Germany			Retrospective study	Tissue	HGSOC	Any expression		I–IV	202	153	49						0.41	0.23–0.71	0.002	0.128
Chatterjee et al., 2017 [16]	Malaysia	2007–2012		Retrospective study	Blood, Ascites Tissue	EOC	IHC score's median level		I	71	28	43	20 mon	1.28	1.09–1.51	0.003	0.0355	1.25	1.09–1.43	0.001	0.0306
Chatterjee et al., 2017 [16]	Malaysia	2007–2012		Retrospective study	Blood, Ascites Tissue	Borderline	IHC score's median level		I	71	28	43	20 mon	1.28	1.09–1.51	0.003	0.0355	1.25	1.09–1.43	0.001	0.0306
Webb et al., 2016 [10]	Canada	1984–2000		Retrospective study	Tissue	HGSOC	>1 positive cells	2,3	I–III	195	112	83	16 yr	0.4864	0.3206–0.7378	0.0007	0.0924
Webb et al., 2016 [10]	Canada	1984–2000		Retrospective study	Tissue	Endometrioid, clear cell, mucinous	>1 positive cells	2,3	I–III	195	112	83	16 yr	0.4864	0.3206–0.7378	0.0007	0.0924
Wang et al., 2017 [11]	China	2007–2012	57 (29–87)	Retrospective study	Tissue	HGSOC	>5% of positive cells		I–IV	107	26	81	49.5 mon	1.299	0.764–2.211	<0.001	0.1178
Zhu et al., 2017 [9]	China	1999–2014		Retrospective study	Tissue	OCCC	10% threshold of cell surface expression		I–IV	122	54	68	33.1 mon	3.032	1.285–7.153	0.011	0.1903	1.970	1.039–3.737	0.038	0.1413
Li et al.,^a 2017 [8]	China	2008–2015	57	Retrospective study	Tissue	HGSOC	>10% of tumor cells		I–IV	113	99	13	5 yr	0.520	0.182–1.487	0.222	0.2327
Li et al.,^b 2017 [8]	China	2008–2015	57	Retrospective study	Tissue	OCCC	>10% of tumor cells		I–IV	95	75	20	5 yr	1.157	0.387–3.456	0.794	0.2424
Mesnage et al., 2017 [15]	France		60 (17–82)	Retrospective study	Immune cell	EOC	Stain >5% cells		II–IV	50	35	15	52 mon					0.78	0.34–1.82	0.560	0.1842
Kim et al., 2018 [13]	Korea	2006–2017		Retrospective study	Tissue	HGSOC	>25% of positive cells		IIIB–IVB	113	101	12	30 mon	1.19	0.50–2.83	0.482	0.1924	1.38	0.70–2.69	0.906	0.1504
Mills et al., 2018 [6]	USA	2010–2015	59.7	Retrospective study	Tissue	HGSOC	>10% of positive cells		I–IV	93	27	66	2.9±1.5 yr	0.61	0.26–1.41	0.001	0.1888
Tai et al.,^a 2018 [17]	China	2000–2015	41 (22–62)	Retrospective study	Tissue	Krukenburg (metastasize from gastric cancer)	presence of staining		NA	35	9	26	17 mon	3.201	1.273–8.050	0.013	0.2041
Tai et al.,^b 2018 [17]	China	2000–2015	41 (22–62)	Retrospective study	Tissue	Krukenburg (metastasize from colorectal cancer)	presence of staining		NA	30	20	10	17 mon	5.129	1.567–16.791	0.007	0.2628

Li et al.^a provided data regarding PD-L1 expression on HGSOC; Li et al.^b provided data regarding PD-L1 expression on OCCC. Tai et al.^a provided data regarding PD-L1 expression and krukenburg metastasized from gastric cancer. Tai et al.^b provided data regarding PD-L1 expression and krukenburg metastasized from colorectal cancer.

PD-L1, programmed cell death ligand-1; HR, hazard ratio; 95% CI, 95% confidence interval; IHC, immunohistochemistry; HGSOC, high-grade serous ovarian cancer; EOC, epithelial ovarian cancer; OCCC, ovarian clear cell carcinoma; NA, not applicable.