Table 1.

Characteristics of the studies included in the meta-analysis

Author	Year	Country	Sample size	Age, years	Specimen	Detection method	Follow-up (months)	End-point	NOS score
Marques et al37	2009	Portugal	321	Median: 51 (22–81)	PB	RT-PCR	median: 43 (3–74)	DFS	7
Li and Zhang34	2016	People’s Republic of China	80	NA	PB	RT-PCR	NA	NA	5
El-Sharkawy et al36	2007	Egypt	48	Range: 25–60	PB	Nested-RT-PCR	NA	NA	5
Lee et al25	2012	South Korea	82	Median: 50 (26–82)	PB	RT-PCR	median: 20.9 (14.5–62.1)	OS/EFS	8
Ntoulia et al17	2006	Greece	101	Median: 53 (26–75)	PB	Nested-RT-PCR	median: 24 (1–80)	OS/DFI	8
Liu et al30	2012	People’s Republic of China	109	Median: 54 (27–76)	PB	RT-PCR	NA	NA	5
Lin et al29	2003	Taiwan	79	Median: 47 (32–85)	PB	RT-PCR	NA	NA	5
Ignatiadis et al15	2008	Greece	175	Median: 54 (28–75)	PB	RT-PCR	NA	OS/DFS	8
Chen et al28	2006	Taiwan	102	NA	PB	membrane array	NA	NA	6
Ceballos et al19	2011	Argentina	65	Range: 29–80	PB	Nested-RT-PCR	NA	NA	6
Zhao et al20	2013	People’s Republic of China	98	Median: 53.2 (33–78)	PB	RT-PCR	NA	OS/PFS	8
Reinholz et al24	2011	America	86	NA	PB	RT-qPCR	NA	OS/PFS	7
Ferrucci et al23	2004	Italy	90	Median: 46 (24–71)	PB	RT-PCR	median: 36	OS/RFS	8
Bolke et al27	2009	Germany	63	NA	PB	RT-PCR	NA	NA	5
Ferro et al18	2010	Italy	190	Median: 63.2 (33–93)	PB	RT-PCR	NA	NA	6
Cerveira et al35	2004	Portugal	54	NA	PB	RT-PCR	NA	NA	5
Grunewald et al31	2000	Austria	133	NA	PB	Nested-RT-PCR	NA	NA	6
Zehentner et al32	2004	USA	84	NA	PB	Real-time-RT-PCR	NA	NA	6
Mikhitarian et al33	2008	USA	215	Median: 56.3 (29–84)	PB	Real-time-RT-PCR	NA	NA	6
Benoy et al26	2006	Belgium	148	Range: 27–88	PB	Real-time-RT-PCR	median: 28.5	OS	7

Note: Data in parenthesis represent ranges.

Abbreviations: NA, not available; PB, peripheral blood; DFS, disease-free survival; OS, overall survival; EFS, event-free survival; DFI, disease-free interval; PFS, progression-free survival; RFS, relapse-free survival; NOS, Newcastle–Ottawa Scale; RT-qPCR, reverse transcription/real-time, quantitative PCR.