Table 1. Detailed information of the eligible studies included in the meta-analysis.

Reference	Population	Ethnicity	No of cases	case/GSTM1			control/GSTM1
				null	present	No of controls	null	present
Cong 201433	Chinese men	Asian	264	142	122	317	135	182
Vogtmann 201434	Chinese men	Asian	335	201	134	638	379	259
Hamachi 201335	Japan men	Asian	455	255	200	1052	546	506
Huang X 201236	Chinese	Asian	100	42	58	130	59	71
Koh 201137	Chinese	Asian	480	234	246	1167	526	641
Wang 201138	India	Asian	302	100	202	291	76	215
Nisa 201039	Japan	Asian	685	357	328	778	422	356
Yang 201040	Chinese	Asian	322	189	133	1247	729	518
Yeh 201041	Taiwan	Asian	722	401	321	733	410	323
Piao 200942	Korean	Asian	1829	1004	825	1699	923	776
Lin LM 200843	Chinese	Asian	120	69	51	204	90	114
Huang LR 200744	Chinese	Asian	57	40	17	68	35	33
Xia XP 200745	Chinese	Asian	112	67	45	140	63	77
Yoshida 200746	Japan	Asian	66	36	30	121	62	59
Fan CH 200647	Chinese	Asian	138	80	58	339	188	151
Fu QH 200648	Chinese	Asian	315	229	86	438	321	117
Luo JG 200649	Chinese	Asian	56	20	36	143	48	95
Probst-Hensch 200650	Chinese	Asian	300	132	168	1168	525	643
Chen K 200451	Chinese	Asian	126	69	56	343	188	151
Huang P 200352	Chinese	Asian	82	46	36	82	28	54
Yang J 200353	Chinese	Asian	58	40	18	65	29	35
Seow 200254	Chinese	Asian	213	108	105	1190	537	653
Wu 200255	Taiwan	Asian	356	173	183	278	136	142
Zhu YQ 200256	Chinese	Asian	104	59	45	101	47	54
Saadat 200157	Iran	Asian	46	25	21	131	53	78
Zhang YC 200158	Chinese	Asian	52	22	30	52	25	27
Inoue 200059	Japan	Asian	205	108	97	220	123	97
Zhou JN 200060	Chinese	Asian	55	34	21	62	33	29
Yoshioka 199961	Japan	Asian	106	56	50	100	42	58
Gao JR 199862	Chinese	Asian	19	7	12	70	25	45
Lee 199863	Singapore	Asian	300	128	172	183	89	94
Guo 199664	Chinese	Asian	19	7	12	23	6	17
Katoh 199665	Japan	Asian	103	56	47	126	55	71