Table 1 Baseline characteristics of eligible studies.

From: A systematic review and meta-analysis: Association between MGMT hypermethylation and the clinicopathological characteristics of non-small-cell lung carcinoma

Study

Year

Country

Ethnicity

Type

Cases Number

Detection Method

Methylation site

Methylation site N(%)

Control style

NOS score

Zöchbauer13

2001

USA

Caucasian

NSCLC

107

MSP

Promoter, CpG islands

22(22.56)

A

8

Zhang3

2011

China

Asian

NSCLC

78

MSP

Promoter, CpG islands

4(5.13)

A

7

Guo15

2015

China

Asian

NSCLC

271

MSP

Promoter, CpG islands

81(29.89)

A

7

Feng18

2008

USA

Caucasian

NSCLC

49

MSP

Promoter, CpG islands

6(12.24)

A

7

Guo11

2004

USA

Caucasian

NSCLC

20

MSP

Promoter, CpG islands

14(70.00)

A

8

Esteller (1)19

1999

USA

Caucasian

NSCLC

22

MSP

Promoter, CpG islands

6(27.27)

A

8

Esteller (2)20

1999

USA

Caucasian

NSCLC

34

MSP

Promoter, CpG islands

10(29.41)

A

8

Ekim21

2011

Turkey

Caucasian

NSCLC

80

MSP

Promoter, CpG islands

51(63.75)

A

7

Brabender22

2003

Germany

Caucasian

NSCLC

90

RT-MSP

Promoter, CpG islands

34(37.78)

A

8

Lin23

2009

China

Caucasian

NSCLC

67

MSP

Promoter, CpG islands

1(1.49)

H

7

Yanagawa24

2007

Japan

Asian

NSCLC

101

MSP

Promoter, CpG islands

14(13.86)

A

8

Kontic25

2012

Serbia

Caucasian

NSCLC

65

MSP

Promoter, CpG islands

8(12.31)

A

7

Kim (1)26

2005

Korea

Asian

AC

72

MSP

Promoter, CpG islands

12(16.67)

A

7

Kim (2)27

2005

Korea

Asian

NSCLC

61

MSP

Promoter, CpG islands

38(62.30)

A

8

Ishiguro28

2013

USA

Caucasian

NSCLC

6

MSP

Promoter, CpG islands

2(33.33)

A

8

Vallböhmer29

2006

Germany

Caucasian

NSCLC

91

RT-MSP

Promoter, CpG islands

38(41.76)

A

8

Safar30

2005

USA

Caucasian

NSCLC

105

MSP

Promoter, CpG islands

11(10.48)

A

7

Drilon31

2014

USA

Caucasian

NSCLC

107

MSP

Promoter, CpG islands

9(8.41)

A

7

Pulling32

2003

USA

Caucasian

AC

237

MSP

Promoter, CpG islands

121(51.05)

A

7

Hayashi33

2002

Japan

Asian

AC

87

MSP

Promoter, CpG islands

31(35.63)

A

8

Liu34

2006

USA

Caucasian

NSCLC

121

MSP

Promoter, CpG islands

37(30.33)

A

7

Chan35

2002

Hong Kong

Asian

NSCLC

75

MSP

Promoter, CpG islands

11(14.67)

A

6

Furonaka36

2005

Japan

Asian

NSCLC

123

MSP

Promoter, CpG islands

47(38.21)

A

7

Wu37

2008

Taiwan

Asian

NSCLC

123

MSP

Promoter, CpG islands

111(50.45)

A

7

Harden38

2003

USA

Caucasian

NSCLC

90

RT-MSP

Promoter, CpG islands

14(15.56)

A

8

Buckingham39

2010

USA

Caucasian

NSCLC

132

Pyrosequencing

Promoter, CpG islands

14(10.61)

A

7

Topaloglu40

2004

USA

Caucasian

NSCLC

31

RT-MSP

Promoter, CpG islands

12(38.71)

A

7

Liu41

2010

China

Asian

NSCLC

98

MSP

Promoter, CpG islands

31(31.63)

H

6

Jin42

2010

China

Asian

NSCLC

94

MSP

Promoter, CpG islands

16(17.02)

A

6

Kang43

2011

China

Asian

NSCLC

77

MSP

Promoter, CpG islands

26(33.77)

H

6

  1. AC: adenocarcinoma; MSP: methylation-specific polymerase chain reaction; RT-MSP: Real-Time MSP; N: number of total; A: autologous control (the control sample from NSCLC themselves); H: heterogeneous control (the control sample from other individuals).