Table 2 |
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|
Relative risks of breast cancer by body fatness at ages 5, 10, and 20 years, and during childhood and adolescence among 109,267 premenopausal Nurses' Health Study II participants (1989–2001) |
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| Casesa (n = 1318) |
Person-years |
Age-adjusted RR (95% CI) |
Multivariate RR (95% CI)b |
|
|
|
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| Figure at age 5 years |
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|
|
||||
| 1 |
350 |
252,779 |
1.00 (ref.) |
1.00 (ref.) |
| 2 |
431 |
335,974 |
0.97 (0.84–1.11) |
0.96 (0.83–1.11) |
| 3 |
304 |
251,625 |
0.89 (0.76–1.04) |
0.88 (0.76–1.03) |
| 4 |
173 |
133,574 |
0.94 (0.78–1.13) |
0.93 (0.77–1.12) |
| ≥ 5 |
60 |
70,740 |
0.59 (0.45–0.78) |
0.57 (0.43–0.75) |
| P for trendc |
0.002 |
0.001 |
||
|
|
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| Figure at age 10 years |
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|
|
||||
| 1 |
277 |
191,720 |
1.00 (ref.) |
1.00 (ref.) |
| 2 |
423 |
323,197 |
0.95 (0.82–1.11) |
0.96 (0.82–1.11) |
| 3 |
307 |
239,185 |
0.92 (0.79–1.09) |
0.93 (0.79–1.10) |
| 4 |
197 |
165,957 |
0.84 (0.70–1.01) |
0.84 (0.70–1.01) |
| ≥ 5 |
114 |
124,633 |
0.62 (0.50–0.77) |
0.61 (0.49–0.76) |
| P for trendc |
<0.0001 |
<0.0001 |
||
|
|
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| Figure at age 20 years |
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|
|
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| 1 |
73 |
44,399 |
1.00 (ref.) |
1.00 (ref.) |
| 2 |
414 |
271,292 |
1.04 (0.81–1.33) |
1.05 (0.82–1.35) |
| 3 |
474 |
397,651 |
0.85 (0.67–1.09) |
0.87 (0.68–1.11) |
| 4 |
247 |
219,136 |
0.81 (0.62–1.05) |
0.81 (0.63–1.06) |
| ≥ 5 |
110 |
112,213 |
0.71 (0.53–0.95) |
0.70 (0.52–0.94) |
| P for trendc |
<0.0001 |
<0.0001 |
||
|
|
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| Average childhood figure (ages 5–10 years) |
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|
|
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| 1 |
262 |
177,512 |
1.00 (ref.) |
1.00 (ref.) |
| 1.5–2 |
416 |
322,714 |
0.92 (0.79–1.08) |
0.93 (0.79–1.08) |
| 2.5–3 |
339 |
265,111 |
0.90 (0.77–1.06) |
0.90 (0.76–1.06) |
| 3.5–4.5 |
253 |
215,175 |
0.82 (0.69–0.97) |
0.81 (0.68–0.96) |
| ≥ 5 |
48 |
64,180 |
0.49 (0.36–0.67) |
0.48 (0.35–0.65) |
| P for trendc |
<0.0001 |
<0.0001 |
||
|
|
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| Average adolescent figure (ages 10–20 years) |
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|
|
||||
| 1 |
56 |
34,780 |
1.00 (ref.) |
1.00 (ref.) |
| 1.5–2 |
398 |
267,086 |
1.07 (0.81–1.41) |
1.08 (0.82–1.43) |
| 2.5–3 |
449 |
366,516 |
0.92 (0.69–1.21) |
0.93 (0.71–1.24) |
| 3.5–4.5 |
363 |
312,070 |
0.85 (0.64–1.13) |
0.86 (0.65–1.14) |
| ≥ 5 |
52 |
64,240 |
0.58 (0.40–0.85) |
0.57 (0.39–0.83) |
| P for trendc |
<0.0001 |
<0.0001 |
||
|
|
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|
aIncluding both invasive and in situ cases. bAdjusted for age (months), time period (6 periods), birthweight (<5.5, 5.5–6.9, 7–8.4, 8.5–9.9, ≥ 10 lb), height (inches), recent alcohol consumption (0, 0.1–1.4, 1.5–4.9, 5.0–9.9, ≥ 10 g/day), parity and age at first birth (nulliparous, 1–2 pregnancies with age at first birth <25 years, 1–2 pregnancies with age at first birth 25–29 years, 1–2 pregnancies with age at first birth ≥ 30 years, ≥ 3 pregnancies with age at first birth <25 years, ≥ 3 pregnancies with age at first birth 25–29 years, ≥ 3 pregnancies with age at first birth ≥ 30 years), oral contraceptive use (never, past use <4 years, past use ≥ 4 years, current use <4 years, current use ≥ 4 years), history of benign breast disease (yes, no), and first-degree family history of breast cancer (yes, no). cWald test of coefficient for body fatness modeled as an ordinal variable. CI, confidence interval; RR, relative risk. |
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|
Baer et al. Breast Cancer Research 2005 7:R314 doi:10.1186/bcr998 |
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