Table 2.

Summary of meta-analysis results.

Variables	No. of studies	Pooled HR (95% CI)	P value	Heterogeneity (I2, P)
OS	9	1.70 (1.22–2.37)	.002	99.5%, <.001
Country
Asian	6	1.89 (1.39–2.58)	<.001	36.5%, .163
Non-Asian	2	1.80 (1.75–1.85)	<.001	0.0%, .762
Tumor type
Mixed	3	2.11 (1.51–2.94)	<.001	0.0%, .482
Cutaneous	2	2.41 (1.09–5.30)	.029	68.5%, <.075
Acral	2	1.49 (1.13–1.95)	.004	0.0%, .693
Mucosal	1	3.20 (0.54–18.88)	—	—
Metastatic status
Mixed	2	2.46 (1.66–3.67)	<.001	0.0%, .768
Metastatic	3	1.55 (1.16–2.06)	.003	0.0%, .981
Non-metastatic	3	1.84 (1.28–2.64)	.001	54.7%, .110
Treatment
Mixed	2	2.46 (1.66–3.67)	<.001	0.0%, .768
Immunotherapy	3	1.55 (1.16–2.06)	.003	0.0%, .981
Surgical resection	3	1.84 (1.28–2.64)	.001	54.7%, .110
Cutoff value of PLR
Cutoff <120	4	1.85 (1.36–2.53)	<.001	37.7%, .186
Cutoff >120	4	1.80 (1.41–2.30)	<.001	5.0%, .368
PFS	6	1.65 (1.10–2.47)	.016	95.8%, <.001
Country
Asian	3	1.62 (1.25–2.09)	<.001	0.0%, .844
Non-Asian	2	1.92 (1.70–2.18)	<.001	0.0%, .384
Tumor type
Mixed	2	2.23 (1.41–3.54)	.001	0.0%, .572
Cutaneous	1	1.90 (1.70–2.20)	—	—
Acral	1	1.56 (1.18–2.07)	—	—
Mucosal	1	1.95 (0.48–8.02)	—	—
Metastatic status
Mixed	1	1.95 (0.48–8.02)	—	—
Metastatic	3	1.72 (1.35–2.20)	<.001	0.4%, .366
Non-metastatic	1	1.90 (1.70–2.20)	—	—
Treatment
Mixed	1	1.95 (0.48–8.02)	—	—
Immunotherapy	2	1.83 (1.18–2.82)	.007	47.8%, .166
Chemotherapy	1	1.91 (0.94–3.90)	—	—
Surgical resection	1	1.90 (1.70–2.20)	—	—
Cutoff value of PLR
Cutoff <120	2	1.90 (1.67–2.16)	<.001	0.0%, .970
Cutoff >120	3	1.72 (1.35–2.20)	<.001	0.4%, .366

CI = confidence interval, HR = hazard ratio, OS = overall survival, PFS = progression-free survival, PLR = platelet lymphocyte ratio.