Polymorphisms of ER-α PvuII and XbaI and breast cancer risk by selected estrogen exposure-related factors and lifestyle factors, Shanghai Breast Cancer Study, 1996–1998
| PvuII polymorphism | XbaI polymorphism | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PP | Pp or pp | XX | Xx or xx | |||||||||||||
| Case/control | ORa (95% CI) | Case/control | ORa (95% CI) | Case/control | ORa (95% CI) | Case/control | ORa (95% CI) | |||||||||
| Age at menarche (yr) | ||||||||||||||||
| ≤13 | 98/140 | 1.0 (ref) | 619/707 | 1.3 (1.0–1.7) | 29/37 | 1.0 (ref)b | 698/813 | 1.1 (0.6–1.8) | ||||||||
| >13 | 38/47 | 1.0 (ref) | 298/250 | 1.5 (1.0–2.4) | 7/11 | 1.0 (ref) | 327/289 | 1.5 (0.6–4.1) | ||||||||
| Age at menopause (yr)c | ||||||||||||||||
| <50 | 26/45 | 1.0 (ref) | 176/209 | 1.4 (0.8–2.4) | 7/13 | 1.0 (ref) | 196/246 | 1.5 (0.6–3.9) | ||||||||
| ≥50 | 18/24 | 1.0 (ref) | 122/128 | 1.3 (0.7–2.4) | 3/4 | 1.0 (ref) | 139/148 | 1.3 (0.3–5.7) | ||||||||
| Years of menstruationd | ||||||||||||||||
| <Median (30 yr) | 54/85 | 1.0 (ref) | 396/470 | 1.4 (0.9–2.0) | 19/26 | 1.0 (ref) | 431/538 | 1.0 (0.6–1.9) | ||||||||
| ≥Median (30 yr) | 82/102 | 1.0 (ref) | 523/489 | 1.3 (1.0–1.8) | 17/22 | 1.0 (ref) | 596/566 | 1.4 (0.7–2.6) | ||||||||
| Ever diagnosed with breast fibroadenoma | ||||||||||||||||
| No | 119/179 | 1.0 (ref) | 830/906 | 1.4 (1.1–1.8) | 32/46 | 1.0 (ref) | 924/1046 | 1.2 (0.8–2.0) | ||||||||
| Yes | 16/8 | 1.0 (ref) | 89/53 | 0.9 (0.4–2.2) | 4/2 | 1.0 (ref) | 102/58 | 0.9 (0.2–5.0) | ||||||||
| BMI | ||||||||||||||||
| <25 | 93/136 | 1.0 (ref) | 635/706 | 1.4 (1.0–1.8) | 29/34 | 1.0 (ref) | 704/807 | 1.0 (0.6–1.6) | ||||||||
| ≥25 | 43/51 | 1.0 (ref) | 284/253 | 1.3 (0.9–2.1) | 7/14 | 1.0 (ref) | 323/297 | 2.1 (0.9–5.4) | ||||||||
| BMIc | ||||||||||||||||
| <25 | 22/43 | 1.0 (ref) | 168/211 | 1.6 (0.9–2.7) | 6/10 | 1.0 (ref) | 185/245 | 1.4 (0.5–3.8) | ||||||||
| ≥25 | 22/26 | 1.0 (ref) | 130/126 | 1.3 (0.7–2.4) | 4/7 | 1.0 (ref) | 150/149 | 1.8 (0.5–6.4) | ||||||||
| WHR | ||||||||||||||||
| ≤0.84 | 102/154 | 1.0 (ref) | 674/757 | 1.4 (1.0–1.8) | 27/38 | 1.0 (ref) | 756/878 | 1.2 (0.7–2.0) | ||||||||
| >0.84 | 34/33 | 1.0 (ref) | 245/202 | 1.2 (0.7–2.0) | 9/10 | 1.0 (ref) | 271/226 | 1.3 (0.5–3.2) | ||||||||
| Regular exercise during past 10 years | ||||||||||||||||
| Yes | 26/56 | 1.0 (ref) | 176/240 | 1.5 (0.9–2.6) | 4/8 | 1.0 (ref) | 199/286 | 1.3 (0.4–4.3) | ||||||||
| No | 110/131 | 1.0 (ref) | 742/719 | 1.3 (1.0–1.7) | 32/40 | 1.0 (ref) | 827/818 | 1.2 (0.8–2.0) | ||||||||
| Caloric intake | ||||||||||||||||
| <Medium | 64/94 | 1.0 (ref) | 452/484 | 1.4 (1.0–1.9) | 17/24 | 1.0 (ref) | 505/556 | 1.3 (0.7–2.5) | ||||||||
| ≥Medium | 72/93 | 1.0 (ref) | 467/475 | 1.3 (1.0–1.9) | 19/24 | 1.0 (ref) | 522/548 | 1.1 (0.6–2.0) | ||||||||
| Fat intake | ||||||||||||||||
| <Medium | 62/83 | 1.0 (ref) | 436/490 | 1.2 (0.8–1.7) | 16/26 | 1.0 (ref) | 489/550 | 1.5 (0.8–2.8) | ||||||||
| ≥Medium | 74/104 | 1.0 (ref) | 483/469 | 1.5 (1.1–2.1) | 20/22 | 1.0 (ref) | 538/554 | 1.0 (0.6–1.9) | ||||||||
| Protein intake | ||||||||||||||||
| <Medium | 60/95 | 1.0 (ref) | 440/482 | 1.4 (1.0–2.0) | 17/26 | 1.0 (ref) | 489/553 | 1.4 (0.7–2.5) | ||||||||
| ≥Medium | 76/92 | 1.0 (ref) | 479/477 | 1.3 (0.9–1.8) | 19/22 | 1.0 (ref) | 538/551 | 1.1 (0.6–2.0) | ||||||||
| Carbohydrate intake | ||||||||||||||||
| <Medium | 62/98 | 1.0 (ref) | 458/480 | 1.5 (1.0–2.1) | 20/19 | 1.0 (ref) | 505/556 | 0.9 (0.5–1.6) | ||||||||
| ≥Medium | 74/89 | 1.0 (ref) | 461/479 | 1.2 (0.9–1.7) | 16/29 | 1.0 (ref) | 522/548 | 1.6 (0.9–3.0) | ||||||||
a Adjusted for age.
b ref, reference.
c Among postmenopausal women only.
d Years of menstruation = menopausal age or age at interview for premenopausal women − menarche age.