Table 3.

Association between urinary level of PGE-M and risk of breast cancer, stratified by menopausal status and BMI

OverallBMI < 25BMI ≥ 25
PGE-M, ng/mg CrCases/controlsOR (95% CI)aCases/controlsOR (95% CI)aCases/controlsOR (95% CI)aPinteractionb
All women
 Q1 (<1.99)145/2701.00 (ref.)98/1791.00 (ref.)47/911.00 (ref.)
 Q2 (1.99–2.28)118/2710.88 (0.65–1.19)82/1900.85 (0.59–1.23)36/811.01 (0.58–1.76)
 Q3 (2.29–2.63)123/2710.97 (0.71–1.33)70/1650.89 (0.60–1.34)53/1061.10 (0.66–1.84)0.943
 Q4 (>2.63)118/2701.07 (0.77–1.48)59/1381.13 (0.72–1.76)59/1320.99 (0.60–1.64)
Plinear trend0.6090.6910.977
Postmenopausal women
 Q1 (<2.13)60/1501.00 (ref.)26/881.00 (ref.)34/621.00 (ref.)
 Q2 (2.13–2.42)60/1491.02 (0.66–1.58)30/871.06 (0.56–1.99)30/620.98 (0.52–1.85)
 Q3 (2.43–2.72)53/1531.03 (0.66–1.16)31/851.50 (0.79–2.83)22/680.72 (0.37–1.40)0.012
 Q4 (>2.72)72/1511.39 (0.90–2.15)38/732.32 (1.24–4.41)34/780.88 (0.47–1.63)
Plinear trend0.1470.0050.516
Premenopausal women
 Q1 (<1.85)71/1191.00 (ref.)58/851.00 (ref.)21/341.00 (ref.)
 Q2 (1.85–2.11)76/1211.11 (0.73–1.69)56/940.87 (0.54–1.41)20/272.38 (0.94–6.01)
 Q3 (2.12–2.42)48/1180.73 (0.46–1.16)37/920.61 (0.36–1.02)11/261.70 (0.60–4.87)0.266
 Q4 (>2.42)64/1211.00 (0.65–1.55)33/680.82 (0.47–1.42)31/531.63 (0.70–3.69)
Plinear trend0.5890.1980.622
Pinteractionc = 0.021
  • aDerived from unconditional logistic regression and adjusted for age (continuous variable), education (<high school or ≥high school), cigarette smoking status (nonsmokers or ever-smokers), number of live births (0, 1, or ≥2), and months of breastfeeding (four levels: <6.0, 6.0–11.9, 12.0–24.0, and >24.0).

  • bPinteraction between urinary PGE-M (continuous variable) and BMI (<25 kg/m2 or ≥25 kg/m2).

  • cPinteraction between urinary PGE-M (continuous variable) and menopausal status (premenopausal or postmenopausal).