Table 1.

Characteristics of the studies included in the meta-analysis (n=8)

Study	Year	Cancer type	Tumor stage	Sample size	Cutoff value	Laboratory method	PT	Follow-up months	Survival analysis	Outcome measures	HR (95% CI)	HR estimation method	NOS
Zhou et al18	2017	GC	I–IV	69	Median	qRT-PCR	No	70	Univariate	OS	0.37 (0.15–0.94)	Indirectly	7
Yu et al21	2017	Pancreatic cancer	I–IV	110	Median	qRT-PCR	NA	48	Univariate, multivariate	OS	0.409 (0.241–0.691)	Directly	8
Xiong et al22	2017	Thyroid carcinoma	I–IV	86	Mean	qRT-PCR	No	32	Univariate, multivariate	OS	0.105 (0.011–1.045)	Directly	8
Wang et al23	2017	Glioma	I–IV	47	Median	qRT-PCR	No	60	Univariate, multivariate	OS	0.316 (0.170–0.536)	Directly	8
Wang et al24	2017	Lung adenocacinoma	I–IV	63	Median	qRT-PCR	No	60	Univariate	OS	0.45 (0.24–0.83)	Indirectly	7
Wang et al25	2017	HCC	I–IV	75	Median	qRT-PCR	No	36	Univariate	OS, DFS	OS: 0.40 (0.21–0.77)	Indirectly	7
Liao et al26	2017	Glioma	I–IV	57	Median	qRT-PCR	NA	36	Univariate, multivariate	OS	0.530 (0.285–0.985)	Directly	8
He et al14	2016	NSCLC	I–IV	76	Median	qRT-PCR	No	60	Univariate, multivariate	OS	0.27 (0.99–0.768)	Directly	8

Abbreviations: GC, gastric cancer; HCC, hepatocellular carcinoma; NSCLC, nonsmall cell–lung cancer; PT, preoperative treatment; NA, not available; OS, overall survival; DFS, disease-free survival; HR, hazard ratio; CI, confidence interval; NOS, Newcastle–Ottawa Scale; qRT-PCR, quantitative real time polymerase chain reaction.