Table 1.

Main characteristics of studies included in the meta-analysis

First author	Publication year	Case nationality	Dominant geography	Sample size	Mean age	Malignant disease	Survival analysis	Source of HR	Follow-up months	NOS score
Higashi1	2015	Japan	Asian	114	67.4	Pancreatic cancer	OS	Reported	40	7
Majhi	2013	USA	Western	29	NA	NSCLC	OS	SC	144	5
Khanh	2013	Japan	Asian	206	NA	Colorectal cancer	OS/RFS	Reported	144	8
Lee	2012	Korea	Asian	63	66.9	Gallbladder cancer	OS	Reported	122	7
Higashi2	2012	Japan	Asian	63	67.4	Cholangio cancer	OS	Reported	NA	8
Hamada	2012	Japan	Asian	150	64.5	OSCC	OS/DFS	Reported/SC	206	8
Yi Zhu	2011	China	Asian	57	61.7	Pancreatic cancer	OS	Reported	40	7
Shanmugam	2010	England	Western	132	65	Colorectal cancer	OS	Reported	300	8
Aloysius	2010	England	Western	104	NA	Periampullary cancer	OS	Reported	36	6
Yeh CN	2009	China	Asian	51	60	Cholangio cancer	OS	Reported	70.1	8
Westgaard	2009	Norway	Western	65	68	Pancreatic cancer	OS	SC	60	7
Tsutsumida	2007	Japan	Asian	185	67	Lung cancer	OS/RFS	SC	100	7
Morrison	2007	USA	Western	295	NA	Endometrial cancer	OS/PFS	Reported	NA	6
Tamada	2006	Japan	Asian	70	69.2	Cholangio cancer	OS	Reported	100	8
Chauhan	2006	USA	Western	38	NA	Ovarian cancer	OS	SC	108	7
Saitou	2005	Japan	Asian	135	65.8	Pancreatic cancer	OS	Reported	155	7
Weed	2004	USA	Western	149	NA	Upper Aerodigestive Tract cancer	OS/RFS	Reported	108	6
Shibahara	2004	Japan	Asian	27	65.3	Cholangio cancer	OS	Reported	60	7

OS, overall survival; DFS, disease-free survival; RFS, recurrence-free survival; PFS,progression-free survival; NSCLC, non-small cell lung cancer; OSCC, oral squamous cell carcinoma; NA, not available; SC, survival curve.