Table 1. Characteristics of eligible case–control studies included in this meta-analysis.

First author	Year	Country	Ethnicity	Cancer Type	Source of controls	Genotyping method	Number (case/control)	HWE	NOS score
Gao et al. [21]	2011	China	Asian	EC	HB	PCR	132/254	Yes	6
Xu et al. [35]	2017	China	Asian	NSCLC	PB	PCR	113/150	Yes	8
Zidi et al. [36]	2016	Tunisia	African	Breast cancer	PB	PCR	104/83	Yes	8
Zambra et al. [37]	2016	Brazil	Mixed	Prostate cancer	HB	PCR	187/129	Yes	7
Yang et al. [22]	2014	Taiwan	Asian	Cervical cancer	HB	PCR	315/400	Yes	7
Silva et al. [38]	2013	Brazil	Mixed	Cervical cancer	HB	PCR	55/50	Yes	7
Agnihotri et al. [39]	2017	India	Asian	HNSCC	PB	DNA-PAGE	383/383	Yes	8
Wisniewski et al. [40]	2015	Poland	Caucasian	NSCLC	PB	PCR	319/465	Yes	8
Teixeira et al. [41]	2013	Brazil	Mixed	HCC	PB	PCR	109/202	Yes	7
Haghi et al. [42]	2015	Iran	Asian	Breast cancer	PB	PCR	227/255	No	7
Garziera et al. [43]	2016	Italy	Caucasian	CRC	PB	PCR	308/294	Yes	8
Chen et al. [44]	2012	China	Asian	EC	HB	PCR	239/467	Yes	7
Tawfeek et al. [45]	2018	Egypt	African	NHL	PB	PCR	150/100	Yes	8
Dardano et al. [23]	2012	Italy	Caucasian	Thyroid cancer	HB	PCR	183/245	Yes	7
Ramos et al. [11]	2014	Brazil	Mixed	Breast cancer	HB	PCR	80/191	Yes	7
Eskandari-Nasab et al. [46]	2013	Iran	Asian	Breast cancer	PB	PCR	236/203	Yes	8
Lau et al. [24]	2011	Australia	Caucasian	Neuroblastoma	PB	PCR	153/404	Yes	8
Kim et al. [47]	2013	Korea	Asian	HCC	HB	PCR	270/91	Yes	7
Jiang et al. [13]	2011	China	Asian	HCC	PB	PCR	318/599	Yes	8
Jeong et al. [48]	2014	Korea	Asian	Breast cancer	HB	PCR	80/80	Yes	7
Ferguson et al. [49]	2012	Canada	Caucasian	Cervical cancer	HB	PCR	539/833	Yes	7
Bortolotti et al. [50]	2014	Italy	Caucasian	Cervical cancer	HB	PCR	100/100	Yes	7
Castelli et al. [20]	2008	Brazil	Mixed	Bladder cancer	PB	PCR	80/107	Yes	8
Bielska et al. [51]	2015	Poland	Caucasian	NHL	HB	PCR	207/150	Yes	7
de Figueiredo-Feitosa et al. [52]	2017	Brazil	Mixed	Thyroid cancer	PB	PCR	94/156	Yes	8

Abbreviation: HB, hospital-based.