Role of CYP2E1 polymorphisms in breast cancer: a systematic review and meta-analysis

Table 1 Basic characteristics of all eligible studies in the meta-analysis

Author, year	Region	Ethnicity	Case/control	BC confirmation	Genotyping method	Source of control	PI	HWE (yes/no)	QS
Khedhaier, 2008	Tunisia	African	304/244	HC	PCR–RFLP	H-B	rs2031920 C>T	Yes	13
Sangrajrang, 2010	Thailand	Asian	570/479	PC	PCR	H-B	rs2031920 C>T	No	9
McCarty, 2012	Thailand	Mix	1041/1070	PC	TaqMan™	P-B	rs2031920 C>T	No	9
Choi, 2003	Korea	Asian	346/377	HC	PCR	H-B	CYP2E1*5 Rsa I/Rst I	Yes	11
Wu, 2006	Taiwan	Asian	262/225	PC	PCR–RFLP	H-B	CYP2E1*5 Rsa I/Rst I	Yes	11
Zgheib, 2013	Lebanese	Arab	227/99	PC	PCR–RFLP	H-B	CYP2E1*5 Rsa I/Rst I	Yes	10
Chong, 2016	Malaysian	Asian	71/260	PC	PCR–RFLP	H-B	CYP2E1*5 Rsa I/Rst I	Yes	11
Shields, 1996	New York, Niagara and Erie	Caucasian	272/334	PC	PCR–RFLP	P-B	CYP2E1*6 Dra I	Yes	14
Anderson, 2012	Canada	Caucasian	920/960	NM	PCR	P-B	CYP2E1*6 Dra I	Yes	12
Zgheib, 2013	Lebanese	Arab	227/99	PC	PCR–RFLP	H-B	CYP2E1*6 Dra I	Yes	10
Chong, 2016	Malaysian	Asian	71/260	PC	PCR–RFLP	H-B	CYP2E1*6 Dra I	Yes	11

BC breast cancer, HC histologically confirmed, PC pathologically confirmed, NM not mentioned, PCR polymerase chain reaction, PCR–RFLP polymerase chain reaction–restriction fragment length polymorphism, HB hospital-based, PB population-based, PI polymorphism(s) investigated, HWE Hardy–Weinberg equilibrium, QS quality score