Table 1.

Characteristics of postmenopausal breast cancer cases and matched controls, the NYUWHS and the NSMSC (499 cases, 499 controls)

CharacteristicCasesControlsPc
Age at blood sampling (y), median (10th, 90th percentile)60.0 (54.0, 65.1)60.1 (53.8, 65.3)Matched
Age at diagnosis, median (10th, 90th percentile)68.5 (59.9, 75.9)
Age at menarchea, median (10th, 90th percentile)13.0 (11.0, 15.0)13.0 (11.0, 15.0)0.33
Age at menopauseb, median (10th, 90th percentile)50.0 (43.0, 55.0)50.0 (43.0, 54.0)0.22
Age at first birtha, median (10th, 90th percentile)25.0 (20.0, 31.0)24.0 (20.0, 32.0)0.74
 ≤20 years48 (13%)53 (13%)
 21–25 years183 (48%)185 (47%)0.76
 26–30 years107 (28%)109 (28%)
 >30 years41 (11%)49 (12%)
Nulliparousa, n (%)100 (21)81 (17)0.13
Complete oophorectomy, n (%)48 (10)47 (9)0.91
Ever use of oral contraceptivesb, n (%)116 (26)114 (25)0.70
Ever use of HRTb, n (%)57 (13)59 (13)0.97
Family history of breast cancer, n (%)97 (19)100 (20)0.81
Heighta (cm), median (10th, 90th percentile)163.0 (155.0, 170.0)162.0 (154.0, 168.0)0.007
Weighta (kg), median (10th, 90th percentile)67.0 (54.0, 84.0)64.0 (54.0, 82.0)0.006
BMIa (kg/m2), median (10th, 90th percentile)25.5 (20.8, 31.2)24.8 (20.9, 30.9)0.06
Estrone (pg/mL), median (10th, 90th percentile)28.1 (18.6, 52.4)26.5 (15.7, 41.9)<0.0001
  • a≤3% missing data.

  • b≤10% missing data.

  • cCalculated using unconditional logistic regression with adjustment for age. Weight, BMI, and age at first birth (in parous only) were log-transformed.