Table 1.

Study characteristics, n (%)

Ref.	Type of study	Country	Centre	Sample (patients)	Analysis sample	Specimens	Age	Gender (male/female)	Follow-up
Chen et al[22], 2005	Retrospective	Taiwan	Single centre	62	59 (3 cases lost to follow-up)	62	24 (38.7) ≤ 61 yr; 38 (61.3) > 61 yr	34 (54.8)/28 (45.2)	50.5 (31) mo for 59 cases
Imamura et al[8], 2007	Retrospective	Japan	Single centre	95	95 (80 from the K-M curves)	95	64 (11.667) yr	48 (50.5)/47 (49.5)	48.4 (26.1833) mo for 80 cases
Takahashi et al[23], 2003	Retrospective	Japan	Single centre	53	53	53	59.5 (13.3) yr	32 (60.3)/21 (39.6)	81.7 (63.2) mo
Waengertner et al[24], 2011	Retrospective	Brazil	Single centre	79	79	79	58.9 (13) yr	42 (53.2)/37 (46.8)	2.5 (2.8) yr
Wang et al[9], 2009	Retrospective	China	Multicentre	68	68	68	56.8 (14.75) yr	38 (55.9)/30 (44.1)	42.9 (14) mo for 64 patients
Zhao et al[25], 2012	Retrospective	China	Single centre	124	124	124	54.6 (11.667) yr	64 (51.6)/60 (48.4)	52 (32.333) mo