GSTP1 methylation

CDKN2A methylation

RASSF1A methylation

WIF1 methylation

Yes

%

p-value

Yes

%

p-value

Yes

%

p-value

Yes

%

p-value

N

248

19

7.7

55

22.2

82

33.1

135

54.4

Age

Age

0.869

0.120

0.922

0.248

< 60

113

9

8.0

20

17.7

37

32.7

57

50.4

> 60

135

10

7.4

35

25.9

45

33.3

78

57.8

Gender

0.053

0.528

0.200

0.957

Male

140

15

10.7

29

20.7

51

36.4

76

54.3

Female

108

4

3.7

26

24.1

31

28.7

59

54.6

Location

0.725

0.931

0.851

0.787

Colon

134

11

8.2

30

22.4

45

33.6

74

55.2

Rectum

114

8

7.0

25

21.9

37

32.5

61

53.5

Histological subtypes

Adenocarcinoma

187

17

9.1

0.173

52

27.8

<0.001

52

27.8

0.002

107

57.2

0.123

Mucinous adenocarcinoma

54

2

3.7

0.383

3

5.6

<0.001

28

51.9

0.001

21

38.9

0.009

Signet-ring cell adenocarcinoma

7

0

0.0

1.000

0

0.0

0.354

2

28.6

1.000

7

100.0

0.017

Differentiation

Well

12

3

25.0

0.082

2

16.7

0.515

2

16.7

0.515

6

50.0

0.601

Moderate

160

14

8.8

0.717

47

29.4

0.244

49

30.6

0.038

95

59.4

0.147

Poor

15

0

0.0

0.368

3

20.0

0.565

1

6.7

0.072

6

40.0

0.160

Unknown

61

Stages

I

4

0

0.0

1.000

1

25.0

1.000

2

50.0

0.601

2

50.0

1.000

II

112

10

8.9

0.465

33

29.5

0.012

43

38.4

0.106

71

63.4

0.010

III

112

8

7.1

0.736

17

15.2

0.016

30

26.8

0.056

51

45.5

0.011

IV

20

1

5.0

1.000

4

20.0

1.000

7

35.0

0.848

11

55.0

0.958

Lymph node metastasis

0.594

0.011

0.072

0.012

Yes

132

9

6.8

21

15.9

37

28.0

62

47.0

No

116

10

8.6

34

29.3

45

38.8

73

62.9

Distant metastasis

1.000

1.000

0.848

0.958

Yes

20

1

5.0

4

20.0

7

35.0

11

55.0

No

228

18

7.9

51

22.4

75

32.9

124

54.4

Tumor size

0.884

0.491

0.234

0.943

< 5 cm

118

9

7.6

30

25.4

44

37.3

68

57.6

>= 5 cm

98

8

8.2

21

21.4

29

29.6

56

57.1

Unknown

32