Article Figures & Data
Tables
- Table 1.
Characteristics of breast cancer cases and their matched controls at blood collection (1989-1990) among women in the Nurses' Health Study
Characteristic Cases (n = 701) Controls (n = 724) Mean (SD) Age (y) 57.2 (7.0) 57.1 (7.0) Age at menarche (y) 12.4 (2.0) 12.5 (1.5) BMI at age 18 (kg/m2) 21.1 (2.7) 21.4 (2.8) BMI at blood collection (kg/m2) 25.5 (4.8) 25.3 (4.6) Parity* (no. pregnancies >6 mo) 3.2 (1.5) 3.3 (1.6) Age at first birth* (y) 24.7 (4.5) 24.2 (4.8) Age at menopause† (y) 48.1 (8.0) 47.8 (8.0) Plasma 25(OH)D (ng/mL) 31.5 (12.1) 33.1 (12.7) Plasma 1,25(OH)2D (ng/mL)‡ 33.5 (6.9) 33.2 (6.1) Percentage (%) Postmenopausal 68.3 67.5 Family history of breast cancer 16.8 10.2 History of benign breast disease 35.4 25.7 Ever smokers 56.6 51.4 ≥7 alcoholic drinks/wk 14.7 13.3 - Table 2.
RRs and 95% CIs of breast cancer by quintile of plasma 25(OH)D and 1,25(OH)2D
Cases/controls All cases and controls Excluding cases diagnosed 1990-1992 Simple RR* (95% CI) Multivariable RR† (95% CI) Multivariable RR‡ (95% CI) 25(OH)D Quintile 1 159/138 1.00 1.00 1.00 2 149/129 1.00 (0.71-1.39) 0.95 (0.66-1.36) 0.87 (0.56-1.36) 3 125/141 0.75 (0.54-1.06) 0.74 (0.51-1.06) 0.66 (0.43-1.03) 4 144/152 0.80 (0.58-1.11) 0.77 (0.54-1.11) 0.75 (0.48-1.16) 5 124/141 0.73 (0.52-1.05) 0.73 (0.49-1.07) 0.65 (0.40-1.06) Ptrend§ 0.04 0.06 0.06 1,25(OH)2D Quintile 1 138/127 1.00 1.00 1.00 2 111/121 0.79 (0.55-1.13) 0.68 (0.46-1.02) 0.65 (0.40-1.07) 3 117/122 0.84 (0.59-1.20) 0.73 (0.50-1.07) 0.64 (0.40-1.03) 4 123/122 0.87 (0.61-1.24) 0.78 (0.53-1.14) 0.70 (0.44-1.11) 5 129/126 0.89 (0.63-1.26) 0.76 (0.52-1.11) 0.76 (0.47-1.21) Ptrend§ 0.91 0.39 0.28 NOTE: For 25(OH)D, quintile cut points for batch 1 were ≤20, 21 to 28, 29 to 33, 34 to 39, and ≥40 ng/mL; for batch 2, ≤28, 29 to 34, 35 to 39, 40 to 47, and ≥48 ng/mL; and for batch 3, ≤18, 19 to 24, 25 to 29, 30 to 36, and ≥37 ng/mL. For 1,25(OH)2D, quintile cut points were ≤28.5, 28.6 to 31.5, 31.6 to 34.3, 34.4 to 38.1, and ≥38.2 ng/mL.
↵* Conditional logistic regression, adjusted for matching factors (age, fasting status at blood draw, month of blood collection, time of day of blood collection, menopausal status, and current use of postmenopausal hormones).
↵† Conditional logistic regression, adjusted for matching factors, BMI at age 18 (<19, 19-20.9, 21-22.9, 23-24.9, ≥25 kg/m2), parity/age at first birth (nulliparous, 1-4 children/age at first birth <25 years, 1-4 children/age at first birth 25-29 years, 1-4 children/age at first birth ≥30 years, ≥5 children/age at first birth <25years, ≥5 children/age at first birth ≥25 years), family history of breast cancer (no family history, history in mother or sister), history of benign breast disease (no, yes), postmenopausal hormone use (continuous, in months), age at menarche (<12, 12, 13 or ≥14 years), age at menopause (<45, 45-49, 50-55, >55 years), alcohol intake (0, 1-2, 3-6, 7-13, ≥14 drinks per week), and plasma α-carotene (batch-specific quintiles).
↵‡ For 25(OH)D, analyses includes 469 cases and their matched controls. For 1,25(OH)2D, analyses includes 443 cases and their matched controls. Adjusted for all factors in multivariable model above.
↵§ Two-sided Ptrend over quintiles, calculated by using the median value of each quintile as a continuous variable in the multivariable model.
- Table 3.
RRs and 95% CIs for breast cancer by quintile of 25(OH)D and 1,25(OH)2D, stratified by participant's age at blood collection
<60 y ≥60 y Case/controls Multivariable RR* (95% CI) Cases/controls Multivariable RR* (95% CI) 25(OH)D Quintile 1 97/94 1.00 62/47 1.00 2 84/86 0.96 (0.62-1.49) 65/49 1.07 (0.60-1.92) 3 77/87 0.80 (0.51-1.26) 48/57 0.64 (0.35-1.16) 4 90/102 0.85 (0.55-1.32) 54/55 0.68 (0.38-1.24) 5 70/76 0.92 (0.57-1.48) 54/71 0.57 (0.31-1.04) Ptrend† 0.88 0.03 Pinteraction 0.20 1,25(OH)2D Quintile 1 87/81 1.00 60/49 1.00 2 58/71 0.76 (0.47-1.25) 55/53 0.76 (0.42-1.38) 3 70/87 0.72 (0.46-1.15) 50/38 1.00 (0.53-1.88) 4 89/78 1.17 (0.75-1.84) 39/47 0.61 (0.32-1.15) 5 79/79 0.88 (0.56-1.40) 53/51 0.72 (0.40-1.32) Ptrend† 0.91 0.23 Pinteraction 0.41 ↵* RR from unconditional logistic regression adjusted for age, fasting status at blood draw, month of blood collection, time of day of blood collection, BMI at age 18, parity/age at first birth, family history of breast cancer, benign breast disease, age at menarche, plasma α-carotene level, and intake of alcohol. See footnotes to Table 2 for variable categories. Results for postmenopausal women also adjusted for quartile of plasma estradiol (in nonusers of postmenopausal hormones), age at menopause, and total duration of postmenopausal hormone use.
↵† Two-sided Ptrend over quintiles, calculated by using the median value of each quintile as a continuous variable in the multivariable model.