Table 4.

Association of urinary PGE-M levels and risk of breast cancer stratified by median time interval between urine collection and cancer diagnosis among postmenopausal women with a BMI < 25

Cancer diagnosed ≤ 4 years after sample collectionCancer diagnosed > 4 years after sample collection
PGE-M, ng/mg CrCases/controlsOR (95% CI)aCases/controlsOR (95% CI)a
 Q1 (<2.10)10/881.00 (ref.)16/881.00 (ref.)
 Q2 (2.11–2.40)15/871.30 (0.53–3.20)15/870.79 (0.35–1.82)
 Q3 (2.41–2.68)21/852.55 (1.06–6.14)10/851.02 (0.44–2.40)
 Q4 (>2.68)22/733.57 (1.51–8.43)16/731.30 (0.58–2.91)
Plinear trend<0.0010.435
  • 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).