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Table 2 Individual associations between body size and estrogen-receptor-positive breast cancer risk, by menopausal status and HT use

From: Lifetime body size and estrogen-receptor-positive breast cancer risk in the California Teachers Study cohort

  Premenopausal Postmenopausal, current HT use Postmenopausal, not using HT
Cases Person-years HRa 95% CI Cases Person-years HRb 95% CI Cases Person-years HRc 95% CI
Height (in)
 <65 104 96,093 1.0   887 217,680 1.0   484 170,727 1.0  
 65–66 144 124,035 1.10 0.86–1.42 570 178,120 1.20 1.06–1.35
 ≥67 328 68,919 1.19 1.05–1.36
 missing 0 289    4 561    2 1037   
BMI at age 18 (kg/m2)
 <20 99 70,997 1.0   1081 251,998 1.0   883 299,216 1.0  
 20–24 127 119,627 0.77 0.59 – 1.00
 ≥25 17 24,989 0.51 0.31 – 0.86 88 25,018 0.87 0.70–1.08 114 35,847 1.10 0.90–1.34
 missing 5 4805    50 10,144    59 14,821   
BMI at baseline (kg/m2)
 <25 168 150,402 1.0   707 170,986 1.0   523 194,969 1.0  
 ≥25 75 66,602 0.94 0.71–1.24 469 107,832 1.07 0.95–1.21 488 142,483 1.21 1.07–1.37
 missing 5 3414    43 8342    45 12,432   
Weight change (lbs) (age 18 to baseline)
 loss ≥10 163 152,687 1.0   129 29,027 1.16 0.94–1.44 108 36,401 1.35 1.05–1.73
 stable 224 56,783 1.0   148 67,402 1.0  
 gain 10–24 811 191,026 1.11 0.95–1.28 744 231,034 1.42 1.19–1.70
 gain ≥25 79 63,066 1.04 0.79–1.37
 missing 6 4664    55 10,325    56 15,048   
Waist-to-height ratio
 <0.50 127 108,707 1.0   769 180,564 1.0   379 143,507 1.0  
 0.50–0.55 52 44,642 0.92 0.67–1.28 465 135,183 1.15 1.00–1.33
 ≥0.56 229 48,056 1.09 0.94–1.27
 missing 69 67,068    221 58,541    212 71,195   
BMI at 10-year follow up
 <25      140 114,879 1.0   251 145,546 1.0  
 ≥25      113 99,976 1.04 0.81–1.34 344 146,054 1.38 1.17–1.63
 missing      2 51,375    4 42,689   
Weight change (lbs) (baseline to 10-year follow up)
 <10      167 138,882 1.0   345 183,392 1.0  
 ≥10 gain      78 70,971 0.94 0.71-1.23 233 100,302 1.36 1.14-1.61
 missing      10 56,377    21 50,594   
  1. aAdjusted for history of benign breast disease and family history of breast cancer in a first-degree relative; age was the time metric and the model was stratified by age at baseline. bAdjusted for nulliparity and age at first full-term pregnancy, history of benign breast disease, family history of breast cancer in a first-degree relative, average alcohol consumption in the year prior to baseline, and neighborhood socioeconomic status; age was the time metric and the model was stratified by age at baseline. cAdjusted for age at menarche, nulliparity and age at first full-term pregnancy, history of benign breast disease, family history of breast cancer in a first-degree relative, and consumption of a plant-based diet; age was the time metric and the model was stratified by age at baseline. HT hormone therapy, BMI body mass index