Table 1 Association between average methylation and breast cancer risk in EPIC and NOWAC

 By quartile

Q1 [0.529–0.546]

75

41

1.00

Q2 [0.546–0.549]

31

40

0.46

(0.25–0.84)

0.01

Q3 [0.549–0.551]

30

40

0.40

(0.21–0.76)

0.005

Q4 [0.551–0.560]

26

41

0.34

(0.18–0.66)

0.001

Per 1 SD

162

162

0.61

(0.46–0.80)

0.0003

 Time to diagnosis

<3.8

81

81

0.66

(0.46–0.94)

0.02

 (years)

>3.8

81

81

0.54

(0.35–0.83)

0.005

p het = 0.483

 ER status

Negative

18

18

0.49

(0.20–1.24)

0.13

Positive

56

56

0.59

(0.36–0.96)

0.03

p het = 0.725

 By quartile

Q1 [0.527–0.538]

45

42

1.00

Q2 [0.538–0.540]

32

42

0.74

(0.41–1.34)

0.32

Q3 [0.540–0.543]

46

42

1.04

(0.59–1.85)

0.88

Q4 [0.543–0.551]

45

42

0.99

(0.56–1.76)

0.98

Per 1 SD

168

168

1.03

(0.82–1.30)

0.81

 Time to diagnosis

<2.1

84

84

0.92

(0.66–1.29)

0.62

 (years)

>2.1

84

84

1.15

(0.83–1.60)

0.41

p het = 0.351

 ER status

Negative

28

28

0.80

(0.48–1.32)

0.38

Positive

130

130

1.10

(0.84–1.44)

0.50

p het = 0.276