Table 4

Polymorphisms of GSTM1, GSTP1, and GSTT1 and breast cancer risk according to potential risk modifiers, Shanghai Breast Cancer Study, 1996–1998

GSTM1aGSTT1aGSTP1a
PresentNullPresentNullAAAG/GG
Menopausal status
 Pre1.0 (ref)0.89 (0.73–1.08)1.0 (ref)1.01 (0.82–1.23)1.0 (ref)1.09 (0.88–1.34)
 Post0.64 (0.48–0.87)0.69 (0.51–0.92)0.66 (0.45–0.98)0.65 (0.43–0.92)0.70 (0.54–0.91)0.84 (0.61–1.15)
P, interaction0.350.720.67
Menstrual cyclesb
 <3701.0 (ref)0.76 (0.60–0.97)1.0 (ref)1.01 (0.79–1.28)1.0 (ref)1.12 (0.87–1.44)
 ≥3701.07 (0.79–1.45)1.26 (0.94–1.68)1.40 (1.05–1.87)1.35 (1.01–1.80)1.36 (1.04–1.77)1.56 (1.16–2.10)
P, interaction0.010.790.89
Body mass index (kg/m2)
 <22.81.0 (ref)0.96 (0.75–1.22)1.0 (ref)1.01 (0.80–1.28)1.0 (ref)1.01 (0.79–1.30)
 ≥22.81.18 (0.91–1.51)1.14 (0.90–1.44)1.21 (0.96–1.54)1.22 (0.91–1.46)1.09 (0.88–1.34)1.37 (1.07–1.76)
P, interaction0.940.690.22
Passive smoke exposurec
 None1.0 (ref)1.04 (0.70–1.54)1.0 (ref)0.90 (0.61–1.32)1.0 (ref)1.27 (0.84–1.92)
 Any1.01 (0.71–1.42)0.94 (0.67–1.32)0.92 (0.67–1.26)0.88 (0.64–1.22)1.06 (0.80–1.41)0.95 (0.70–1.29)
P, interaction0.650.610.15
Deep fried meat
 Never1.0 (ref)1.06 (0.80–1.41)1.0 (ref)1.21 (0.91–1.61)1.0 (ref)1.08 (0.81–1.46)
 Usually-Always1.16 (0.86–1.56)0.96 (0.73–1.26)1.24 (0.94–1.63)0.96 (0.73–1.27)1.07 (0.84–1.36)0.95 (0.71–1.27)
P, interaction0.220.030.35
  • a Odds ratios adjusted for age. Odds ratio (95% confidence interval).

  • b Number of menstrual cycles = [(current age or age at menopause in menopausal women-age at menarche) × 13] − live births × 9; women with unknown menopausal status were excluded.

  • c Exposure in workplace or to husband smoking.