Table 5 Case-only odds ratios for estrogen receptor-negative breast cancer (excluding in situ) in relation to participant’s exposures
From: Perinatal and postnatal exposures and risk of young-onset breast cancer
Characteristics | ER+ (n = 1124) | ER− (n = 307) | OR (95% CI)¥ | OR (95% CI) |
|---|---|---|---|---|
Preeclampsia/eclampsia/toxemia | n (%) | n (%) | ||
No | 890 (98.0) | 213 (95.9) | 1.00 | 1.00 |
Yes | 18 (2.0) | 9 (4.1) | 2.09 (0.93–4.72) | 2.04 (0.81–5.13)* |
Gestational hypertension§ | ||||
No | 853 (97.9) | 198 (97.1) | 1.00 | 1.00 |
Yes | 18 (2.1) | 6 (2.9) | 1.44 (0.56–3.66) | 1.29 (0.47–3.53)* |
Any hypertensive disorder | ||||
No | 895 (96.1) | 213 (93.4) | 1.00 | 1.00 |
Yes | 36 (3.9) | 15 (6.6) | 1.75 (0.94–3.26) | 1.62 (0.81–3.20)* |
Maternal smoking | ||||
No | 677 (70.2) | 156 (67.2) | 1.00 | |
Yes | 287 (29.8) | 76 (32.8) | 1.15 (0.85–1.56) | |
Low birth weight | ||||
Birth weight > 5.5 pounds | 885 (91.3) | 225 (92.2) | 1.00 | 1.00 |
Birth weight ≤ 5.5 pounds | 84 (8.7) | 19 (7.8) | 0.89 (0.53–1.49) | 0.80 (0.44–1.44)# |
High birth weight | ||||
Birth weight < 8.8 pounds | 715 (89.4) | 185 (92.0) | 1.00 | 1.00 |
Birth weight ≥ 8.8 pounds | 85 (10.6) | 16 (8.0) | 0.73 (0.42–1.27) | 0.66 (0.36–1.22)# |
Breastfed | ||||
No | 606 (62.9) | 151 (65.4) | 1.00 | |
Yes | 358 (37.1) | 80 (34.6) | 0.90 (0.66–1.21) | |
Soy-fed (formula made from soy) | ||||
No | 787 (95.5) | 197 (96.1) | 1.00 | |
Yes | 37 (4.5) | 8 (3.9) | 0.86 (0.40–1.88) | |
DES exposure during pregnancy | ||||
No | 818 (96.7) | 189 (97.4) | 1.00 | |
Yes | 28 (3.3) | 5 (2.6) | 0.77 (0.29–2.03) | |
Short gestational length at birth | ||||
Born ≥ 38 weeks | 517 (85.6) | 118 (84.3) | 1.00 | 1.00 |
Born < 38 weeks | 87 (14.4) | 22 (15.7) | 1.11 (0.67–1.84) | 0.91 (0.52–1.60)# |