Table 1

Distribution of demographic and known risk factors for breast cancer among 1007 controls, 975 breast cancer cases, 656 ductal cases, 196 lobular cases, 796 ER+ cases, and 107 ER− cases

CharacteristicControls (n = 1007)All cases (n = 975)Ductal (n = 656)Lobular (n = 196)ER+ (n = 796)ER− (n = 107)
N%N%N%N%N%N%
Reference age
 65–6933032.830030.820431.15829.624030.24138.3
 70–7438137.838139.125238.48543.431940.13330.8
 75–7929629.429430.220030.55327.023729.83330.8
Race
 White92591.992995.36239518895.975995.410497.2
 Black373.7161.6111.731.5131.621.9
 Asian/Pacific Islander292.9191.9182.710.5172.100.0
 Other/unknown161.6111.140.642.070.910.9
Income
 <$15,00019121.717721.312422.13017.914521.32224.4
 $15–25,00021424.319823.913924.83923.216624.42022.2
 $25–50,00029633.629635.720436.46035.723935.13640.0
 >$50,00018020.415919.29416.83923.213119.21213.3
 Missing126145952811517
Parity
 Nulliparous949.3889.0578.72010.2718.91110.3
 Parous91390.788791.059991.317689.872591.19689.7
Type of menopause
 Natural60761.658361.440062.811359.848362.65855.2
 Induced14815.012913.67812.22915.39612.41817.1
 Simple hysterectomy23121.623725.015925.04724.919325.02927.6
 Missing2126197242
First-degree family history of breast cancer
 No77182.970377.246977.114678.556476.08382.2
 Yes15917.120822.813922.94021.517824.01817.8
 Missing77644810546
BMI, quartiles
 ≤23.3226127.120922.313922.05127.116621.62524.3
 23.33–26.2024125.024025.616425.94322.919625.52827.2
 26.21–30.1123023.924526.116225.65227.720026.02625.2
 ≥30.1223124.024526.116826.54222.320626.82423.3
 Missing4436238284
Smoking status
 Never52351.945046.230145.98945.437346.94844.9
 Former36936.639640.626941.07940.332140.34643.0
 Current11511.412913.28613.12814.310212.81312.1
Smoking duration, pack years
 052352.045046.330146.18945.437347.04845.3
 <1010710.6899.2568.62110.7708.8109.4
 10–2914314.216617.111918.23015.313617.11817.0
 ≥3023323.226727.517727.15628.621527.13029.3
 Missing133021
Ever-use of HRT
 Never/<6 months41341.135236.324337.35930.128535.94038.1
 6 months-5 years15615.511912.38713.42211.29712.21615.2
 ≥5 years43543.349951.432149.311558.741151.84946.7
 Missing355032