Table 6

ORsa and 95% CIs for incidence of breast cancer associated with third-trimester steroid hormone levels (ng/ml) by age at diagnosis and time since index pregnancy

Three cases excluded because of missing date of diagnosis.

OR (95% CI)
Age at Dxb (yrs)Time to Dx (yrs)
≤50 (90 cases; 374 controls)>50 (101 cases; 374 controls)<15 (40 cases; 374 controls)≥15 (151 cases; 374 controls)
Progesterone
 <124.251.01.01.01.0
 124.25 to <197.110.54 (0.27–1.1)0.86 (0.40–1.9)1.0 (0.34–3.2)0.58 (0.32–1.1)
 197.11 to <269.970.41 (0.18–0.92)0.79 (0.34–1.8)0.72 (0.20–2.6)0.52 (0.26–1.0)
 ≥269.970.30 (0.10–0.90)0.87 (0.31–2.5)0.21 (0.02–2.1)0.55 (0.24–1.3)
  P for trend0.040.860.130.33
Estrone
 <3.361.01.01.01.0
 3.36 to <11.030.85 (0.33–2.2)3.5 (1.2–11)5.3 (0.68–42)1.5 (0.67–3.2)
 11.03 to <18.701.0 (0.37–2.9)3.8 (1.2–12)6.1 (0.72–51)1.6 (0.69–3.8)
 ≥18.701.5 (0.52–4.6)2.6 (0.67–10)2.6 (0.21–31)2.2 (0.87–5.6)
  P for trend0.080.520.980.07
Estradiol
 <13.391.01.01.01.0
 13.39 to <26.660.49 (0.20–1.2)1.9 (0.83–4.4)0.68 (0.25–1.8)1.3 (0.61–2.7)
 26.66 to <39.920.63 (0.25–1.6)1.8 (0.73–4.6)0.78 (0.26–2.4)1.4 (0.61–3.1)
 ≥39.920.42 (0.14–1.3)0.82 (0.24–2.8)0.16 (0.02–1.4)0.94 (0.36–2.5)
  P for trend0.690.660.220.95
Estriol
 <7.391.01.01.01.0
 7.39 to <13.521.3 (0.52–3.2)2.7 (0.87–8.1)2.2 (0.48–10)1.7 (0.78–3.8)
 13.52 to <19.651.3 (0.54–3.4)2.5 (0.81–7.8)1.9 (0.41–9.1)1.8 (0.79–4.0)
 ≥19.650.81 (0.24–2.8)1.9 (0.51–7.2)1.5 (0.23–9.5)1.2 (0.43–3.3)
  P for trend0.600.900.820.94
  • a Controlling for age at index pregnancy, number of previous full-term pregnancies, and age at first full-term pregnancy.

  • b Dx, diagnosis.