Table 1.

Main characteristics of the studies included in the meta-analysis

Author	Year	circRNAs profiles	Cancer type	Specimen	Test method	Sample size (case/control)	Sensitivity	Specificity
Li et al.8	2017	hsa_circ_0000096	GC	Tissues	qRT–PCR	101/101	0.880	0.560
Zhu et al.9	2017	hsa_circ_0013958	LAC	Tissues	qRT–PCR	49/49	0.755	0.796
		hsa_circ_0013958	LAC	Plasma	qRT–PCR	30/30	0.667	0.933
Yin et al.10	2017	hsa_circ_0001785	BC	Plasma	qRT–PCR	20/20	0.786	0.756
		hsa_circ_0108942	BC	Plasma	qRT–PCR	20/20	0.815	0.504
		hsa_circ_0068033	BC	Plasma	qRT–PCR	20/20	0.732	0.578
Zhao et al.11	2017	hsa_circ_0000181	GC	Tissues	qRT–PCR	115/115	0.539	0.852
		hsa_circ_0000181	GC	Plasma	qRT–PCR	102/105	0.990	0.206
Fu et al.12	2017	hsa_circ_0003570	HCC	Tissues	qRT–PCR	107/107	0.449	0.868
Li et al.13	2017	hsa circ 0001649	GC	Tissues	qRT–PCR	76/76	0.711	0.816
Qin et al.14	2015	hsa_circ_0001649	HCC	Tissues	qRT–PCR	89/89	0.810	0.690
Wang et al.15	2015	hsa_circ_001988	CRC	Tissues	qRT–PCR	31/31	0.680	0.730
Yao et al.16	2017	circZKSCAN1	HCC	Tissues	qRT–PCR	102/102	0.822	0.724
Zhuo et al.17	2017	circRNA0003906	CRC	Tissues	qRT–PCR	122/40	0.725	0.803
Li et al.18	2017	hsa_circ_0001017	GC	Plasma	qRT–PCR	121/121	0.974	0.811
		hsa_circ_0061276	GC	Plasma	qRT–PCR	121/121	0.903	0.517
Shang et al.19	2016	hsa_circ_0005075	HCC	Tissues	qRT–PCR	30/30	0.833	0.900
Li et al.20	2015	hsa_circ_002059	GC	Tissues	qRT–PCR	101/101	0.810	0.620
Chen et al.21	2017	hsa_circ_0000190	GC	Tissues	qRT–PCR	104/104	0.721	0.683
		hsa_circ_0000190	GC	Plasma	qRT–PCR	104/104	0.414	0.875
Huang et al.22	2017	hsa_circ_0000745	GC	Plasma	qRT–PCR	60/60	0.855	0.450
Lu et al.23	2017	hsa_circ_0006633	GC	Tissues	qRT–PCR	96/96	0.600	0.810
Sun et al.24	2017	hsa_circ_0000520	GC	Tissues	qRT–PCR	56/56	0.536	0.857
		hsa_circ_0000521	GC	Plasma	qRT–PCR	45/17	0.824	0.844
Tian et al.25	2017	hsa_circ_0003159	GC	Tissues	qRT–PCR	108/108	0.852	0.565
Lu et al.26	2018	hsa_circ_0000467	GC	Plasma	qRT–PCR	20/20	0.705	0.648
Zhang et al.27	2018	hsa_circ_0091579	HCC	Tissues	qRT–PCR	30/30	0.970	0.400
		hsa_circ_16245-1	HCC	Tissues	qRT–PCR	30/30	0.830	0.630
Shao et al.28	2017	hsa_circ_0001895	GC	Tissues	qRT–PCR	96/96	0.678	0.857
Wang et al.29	2017	hsa_circ_0000567	CRC	Tissues	qRT–PCR	102/102	0.833	0.765
Zhao et al.30	2018	hsa_circ_0081001	OSCC	Salivary	qRT–PCR	90/82	0.744	0.902
Fu,et al.31	2017	hsa_circ_0004018	HCC	Tissues	qRT–PCR	102/102	0.716	0.815

Abbreviations: GC, gastric cancer; BC, breast cancer; HCC, hepatocellular carcinoma; CRC, colorectal cancer; LAC, lung adenocarcinoma; OSCC, oral squamous cell carcinoma; qRT-PCR, quantitative reverse transcription PCR.