Table 4 Case-only odds ratios for estrogen receptor-negative breast cancer in relation to participant’s exposures
From: Perinatal and postnatal exposures and risk of young-onset breast cancer
Characteristics | ER+ (n = 1356) | ER− (n = 338) | OR (95% CI)¥ | OR (95% CI) |
|---|---|---|---|---|
Preeclampsia/eclampsia/toxemia | n (%) | n (%) | ||
No | 1078 (98.2) | 237 (95.9) | 1.00 | 1.00 |
Yes | 20 (1.8) | 10 (4.1) | 2.27 (1.05–4.92) | 2.23 (0.94–5.30)* |
Gestational hypertension§ | ||||
No | 1031 (97.7) | 222 (97.4) | 1.00 | 1.00 |
Yes | 24 (2.3) | 6 (2.6) | 1.16 (0.47–2.87) | 1.08 (0.40–2.88)* |
Any hypertensive disorder | ||||
No | 1084 (96.1) | 237 (93.7) | 1.00 | 1.00 |
Yes | 44 (3.9) | 16 (6.3) | 1.66 (0.92–3.00) | 1.56 (0.82–2.98)* |
Maternal smoking | ||||
No | 812 (69.6) | 175 (67.8) | 1.00 | |
Yes | 355 (30.4) | 83 (32.2) | 1.08 (0.81–1.45) | |
Low birth weight | ||||
Birth weight > 5.5 pounds | 1075 (91.6) | 247 (92.2) | 1.00 | 1.00 |
Birth weight ≤ 5.5 pounds | 98 (8.4) | 21 (7.8) | 0.93 (0.57–1.52) | 0.86 (0.49–1.49)# |
High birth weight | ||||
Birth weight < 8.8 pounds | 873 (90.3) | 205 (92.8) | 1.00 | 1.00 |
Birth weight ≥ 8.8 pounds | 94 (9.7) | 16 (7.2) | 0.72 (0.42–1.26) | 0.64 (0.35–1.17)# |
Breastfed | ||||
No | 737 (63.2) | 172 (67.2) | 1.00 | |
Yes | 428 (36.8) | 84 (32.8) | 0.84 (0.63–1.12) | |
Soy-fed (formula made from soy) | ||||
No | 958 (95.3) | 218 (96.0) | 1.00 | |
Yes | 47 (4.7) | 9 (4.0) | 0.84 (0.41–1.74) | |
DES exposure during pregnancy | ||||
No | 994 (97.0) | 211 (97.2) | 1.00 | |
Yes | 31 (3.0) | 6 (2.8) | 0.91 (0.38–2.21) | |
Short gestational length at birth | ||||
Born ≥ 38 weeks | 617 (85.3) | 131 (84.0) | 1.00 | 1.00 |
Born < 38 weeks | 106 (14.6) | 25 (16.0) | 1.11 (0.69–1.79) | 0.94 (0.56–1.57)# |