Table 2 Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for breast cancer risk associated with body size at age 7Â years
| Â | KARMA | LIBRO1 | Combined | ||||||
|---|---|---|---|---|---|---|---|---|---|
Body size | Number | Age-adjusted OR (95% CI) | Multivariable OR (95% CI)a | Number | Age-adjusted OR (95% CI) | Multivariable OR (95% CI)a | Number | Age-adjusted OR (95% CI) | Multivariable OR (95% CI)b |
Breast cancer overall | |||||||||
 Small | 1327 | 1.00 (Reference) | 1.00 (Reference) | 2727 | 1.00 (Reference) | 1.00 (Reference) | 4054 | 1.00 (Reference) | 1.00 (Reference) |
 Medium | 773 | 0.89 (0.80–0.98) | 0.88 (0.80–0.98) | 1358 | 0.77 (0.71–0.82) | 0.76 (0.71–0.82) | 2131 | 0.81 (0.76–0.86) | 0.80 (0.76–0.85) |
 Large | 172 | 0.75 (0.63–0.90) | 0.73 (0.61–0.87) | 374 | 0.81 (0.72–0.92) | 0.80 (0.71–0.91) | 546 | 0.79 (0.72–0.87) | 0.78 (0.70–0.86) |
  P trend |  | <0.001 | <0.001 |  | <0.001 | <0.001 |  | <0.001 | <0.001 |
Premenopausal breast cancer | |||||||||
 Small | 422 | 1.00 (Reference) | 1.00 (Reference) | 534 | 1.00 (Reference) | 1.00 (Reference) | 956 | 1.00 (Reference) | 1.00 (Reference) |
 Medium | 259 | 0.94 (0.77–1.14) | 0.90 (0.74–1.09) | 294 | 0.81 (0.69–0.95) | 0.79 (0.67–0.92) | 553 | 0.86 (0.76–0.97) | 0.83 (0.73–0.94) |
 Large | 51 | 0.63 (0.44–0.90) | 0.59 (0.41–0.85) | 85 | 0.86 (0.69–1.11) | 0.80 (0.62–1.04) | 136 | 0.77 (0.63–0.95) | 0.72 (0.58–0.89) |
  P trend |  | 0.015 | 0.004 |  | 0.039 | 0.020 |  | 0.003 | <0.001 |
Postmenopausal breast cancer | |||||||||
 Small | 905 | 1.00 (Reference) | 1.00 (Reference) | 2193 | 1.00 (Reference) | 1.00 (Reference) | 3098 | 1.00 (Reference) | 1.00 (Reference) |
 Medium | 514 | 0.89 (0.79–1.01) | 0.89 (0.78–1.00) | 1064 | 0.76 (0.70–0.83) | 0.76 (0.70–0.83) | 1578 | 0.80 (0.75–0.86) | 0.80 (0.75–0.86) |
 Large | 121 | 0.80 (0.65–0.99) | 0.79 (0.64–0.98) | 289 | 0.80 (0.69–0.92) | 0.80 (0.70–0.93) | 410 | 0.80 (0.71–0.90) | 0.80 (0.71–0.90) |
  P trend |  | 0.018 | 0.014 |  | <0.001 | <0.001 |  | <0.001 | <0.001 |