Table 5.
Stratified odds ratios and 95% confidence intervals for breast cancer risk according to quintiles of season-adjusted residual values of circulating 25(OH)D concentration at enrollment
| Quintiles | ||||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | P trend | P het a | ||
| Caucasiansb | ||||||||
| Cases/controls | 209/399 | 298/449 | 270/469 | 282/473 | 244/471 | 0.46 | 0.31 | |
| OR (95% CI) | 1.00 | 1.28 (1.01, 1.62) | 1.10 (0.87, 1.38) | 1.17 (0.92, 1.48) | 0.97 (0.76, 1.24) | |||
| Age at enrollment, yearsb | ||||||||
| ≤ 45 | Cases/controls | 72/101 | 54/103 | 62/103 | 61/110 | 52/136 | ||
| OR (95% CI) | 1.00 | 0.67 (0.42, 1.07) | 0.78 (0.49, 1.25) | 0.73 (0.46, 1.14) | 0.48 (0.30, 0.79) | 0.01 | 0.08 | |
| 45-54 | Cases/controls | 118/220 | 116/220 | 97/201 | 117/209 | 109/186 | ||
| OR (95% CI) | 1.00 | 0.92 (0.65, 1.29) | 0.82 (0.58, 1.17) | 0.99 (0.70, 1.40) | 1.04 (0.73, 1.48) | 0.73 | ||
| ≥ 55 | Cases/controls | 121/268 | 192/265 | 150/284 | 137/269 | 127/265 | ||
| OR (95% CI) | 1.00 | 1.76 (1.30, 2.38) | 1.28 (0.94, 1.73) | 1.28 (0.94, 1.75) | 1.20 (0.87, 1.66) | 0.96 | ||
| Lag-time to diagnosisb | ||||||||
| ≤ 8 years | Cases/controls | 123/261 | 174/240 | 144/258 | 140/253 | 141/252 | ||
| OR (95% CI) | 1.00 | 1.62 (1.19, 2.22) | 1.23 (0.90, 1.69) | 1.26 (0.92, 1.73) | 1.18 (0.85, 1.63) | 0.99 | 0.30 | |
| > 8 years | Cases/controls | 188/328 | 188/348 | 165/330 | 175/335 | 157/335 | ||
| OR (95% CI) | 1.00 | 0.92 (0.71, 1.20) | 0.86 (0.66, 1.13) | 0.91 (0.70, 1.19) | 0.82 (0.62, 1.08) | 0.20 | ||
| ER statusb | ||||||||
| ER+ | Cases/controls | 173/355 | 219/347 | 178/358 | 200/355 | 78/352 | ||
| OR (95% CI) | 1.00 | 1.31 (1.00, 1.70) | 1.04 (0.80, 1.35) | 1.22 (0.93, 1.58) | 1.10 (0.83, 1.44) | 0.79 | 0.79 | |
| ER- | Cases/controls | 53/99 | 60/99 | 56/111 | 49/93 | 54/95 | ||
| OR (95% CI) | 1.00 | 1.03 (0.63, 1.70) | 0.99 (0.60, 1.64) | 1.00 (0.61, 1.66) | 1.08 (0.64, 1.85) | 0.85 | ||
| Menopausal statusc | ||||||||
| Pre-menopausal | Cases/controls | 150/229 | 128/228 | 122/218 | 123/221 | 114/238 | ||
| OR (95% CI) | 1.00 | 0.80 (0.59, 1.09) | 0.79 (0.58, 1.08) | 0.80 (0.58, 1.09) | 0.67 (0.48, 0.92) | 0.03 | 0.05 | |
| Post-menopausal | Cases/controls | 161/360 | 234/360 | 187/370 | 192/367 | 174/349 | ||
| OR (95% CI) | 1.00 | 1.48 (1.15, 1.90) | 1.16 (0.89, 1.50) | 1.22 (0.94, 1.58) | 1.21 (0.92, 1.58) | 0.67 | ||
| BMIc, kg/m2 | ||||||||
| < 25 | Cases/controls | 115/245 | 153/312 | 164/323 | 195/361 | 192/403 | ||
| OR (95% CI) | 1.00 | 1.01 (0.75, 1.36) | 1.05 (0.78, 1.40) | 1.10 (0.83, 1.47) | 0.97 (0.73, 1.29) | 0.99 | 0.56 | |
| 25+ | Cases/controls | 187/331 | 201/267 | 142/260 | 115/215 | 90/171 | ||
| OR (95% CI) | 1.00 | 1.31 (1.01, 1.70) | 0.93 (0.70, 1.22) | 0.91 (0.68, 1.22) | 0.93 (0.68, 1.27) | 0.16 | ||
| Estrone, pg/mLc, d | ||||||||
| < 23.25 | Cases/controls | 32/90 | 42/85 | 40/94 | 44/97 | 33/102 | ||
| OR (95% CI) | 1.00 | 1.38 (0.79, 2.41) | 1.19 (0.68, 2.09) | 1.36 (0.78, 2.36) | 0.95 (0.53, 1.70) | 0.83 | 0.41 | |
| 23.25-32.45 | Cases/controls | 43/83 | 59/82 | 48/91 | 53/81 | 47/74 | ||
| OR (95% CI) | 1.00 | 1.40 (0.84, 2.33) | 1.03 (0.61, 1.73) | 1.33 (0.78, 2.25) | 1.29 (0.75, 2.22) | 0.49 | ||
| > 32.45 | Cases/controls | 48/83 | 80/94 | 56/80 | 37/82 | 41/52 | ||
| OR (95% CI) | 1.00 | 1.70 (1.05, 2.76) | 1.36 (0.81, 2.27) | 0.87 (0.50, 1.50) | 1.66 (0.94, 2.95) | 0.82 | ||
aCochran's Q statistic was used to test for heterogeneity according to lag-time and estrogen receptor (ER) status. bAdjusted for age at menarche (continuous), family history of breast cancer (yes or no), age at first birth/parity (≤ 20, 21-25, 26-30, > 30 years, nulliparous), body mass index (BMI) (continuous), hormone replacement therapy use (ever or never), and alcohol consumption (continuous). cUnconditional logistic regression analyses adjusted for cohort and age at sampling in addition to all factors in footnote b. dMeasured in post-menopausal women only. 25(OH)D, 25-hydroxyvitamin D; CI, confidence interval; OR, odds ratio.