Covariate | Invasive breast cancer | Breast DCIS | Controls | P valuea |
---|---|---|---|---|
Sample size | 482 | 119 | 667 | - |
Ethnicity (%) | 0.19b | |||
Hawaiian | 14.3 | 8.4 | 24.3 | |
Japanese | 46.5 | 55.5 | 43.8 | |
Caucasian | 32.6 | 28.6 | 28.0 | |
Other | 6.6 | 7.6 | 3.9 | |
Age at diagnosis (years) | 63.5 | 62.9 | N/A | 0.50b |
Age at recruitment (years) | 60.0 | 59.6 | 56.7 | 0.58b |
Mean age at all mammograms (years) | 59.8 | 59.1 | 59.7 | 0.70 |
Body mass index (kg/m2) | 25.2 | 24.5 | 25.7 | 0.07 |
Time from first mammogram to diagnosis (years) | 6.2 | 6.7 | N/A | 0.17b |
Family history of breast cancer (%) | 16.8 | 16.8 | 12.0 | 0.05 |
Age at first birth (years) | 25.0 | 25.1 | 24.7 | 0.65 |
Age at menarche (years) | 13.1 | 12.9 | 13.1 | 0.47 |
Parous (%) | 84.5 | 83.9 | 88.5 | 0.10 |
Number of children | 2.4 | 2.2 | 2.6 | 0.02 |
Postmenopausal (%) | 86.3 | 89.9 | 77.7 | <0.0001 |
Ever HRT use (%) | 67.2 | 73.9 | 69.3 | 0.01 |
Number of mammograms | 3.2c | 3.4c | 2.4c | <0.0001 |
Breast percent densityd | 36.5 | 38.2 | 29.4 | <0.0001 |
Breast dense aread (cm2) | 36.7 | 34.9 | 28.7 | <0.0001 |
Total breast aread (cm2) | 114.5 | 106.9 | 118.9 | 0.08 |