Table 1.

Selected characteristics of controls, invasive ductal carcinoma cases, and invasive lobular carcinoma cases

Controls (n = 1,474)
Ductal carcinoma (n = 1,199)
Lobular carcinoma (n = 739)
n (%)n (%)n (%)
Reference age (y)
    55-59137 (9.3)140 (11.7)162 (21.9)
    60-64121 (8.2)125 (10.4)139 (18.8)
    65-69442 (30.0)341 (28.4)189 (25.5)
    70-74478 (32.4)380 (31.7)195 (26.4)
    75-79296 (20.1)213 (17.7)54 (7.3)
Race
    White (non-Hispanic)1,346 (91.3)1,116 (93.1)688 (93.1)
    Black45 (3.1)22 (1.8)16 (2.2)
    Asian/Pacific Islander38 (2.6)35 (2.9)11 (1.5)
    Other/unknown45 (3.0)26 (2.2)24 (3.2)
Education
    Less than high school177 (12.0)127 (10.6)53 (7.2)
    High school520 (35.3)403 (33.6)221 (29.9)
    Some college467 (31.7)407 (33.9)238 (32.2)
    College/college graduate309 (21.0)262 (21.9)227 (30.7)
    Missing100
Parity
    Nulliparous130 (8.8)126 (10.5)99 (13.4)
    Parous1,344 (91.2)1,073 (89.5)640 (86.6)
Age at first birth (y)
    14-19273 (20.4)201 (18.8)124 (19.5)
    20-24650 (48.5)519 (48.6)306 (48.0)
    25-29305 (22.7)244 (22.8)136 (21.4)
    30-42113 (8.4)105 (9.8)71 (11.1)
    Missing133130102
Use of oral contraceptives (mo)
    0907 (63.4)721 (63.0)339 (49.2)
    6-59297 (20.8)219 (19.1)193 (28.0)
    60-409227 (15.9)204 (17.8)157 (22.8)
    Missing435550
Recency of menopausal hormone therapy use
    Never user433 (32.4)323 (29.9)134 (19.3)
    Former user of hormone therapy246 (18.4)185 (17.1)96 (13.9)
    Current EHT user450 (33.6)297 (27.5)195 (28.1)
    Current CHT user209 (15.6)276 (25.5)268 (38.7)
    Missing13611846
First-degree family history of breast cancer
    No1,153 (83.4)878 (77.3)556 (77.3)
    Yes229 (16.6)258 (22.7)163 (22.7)
    Missing926320
Body mass index, quartiles (kg/m2)
    ≤23.16363 (25.4)265 (22.6)210 (29.0)
    23.17-26.44372 (26.1)309 (26.4)154 (21.3)
    26.45-30.82343 (24.0)283 (24.1)200 (27.6)
    ≥30.83350 (24.5)315 (26.9)160 (22.1)
    Missing462715
  • Abbreviations: EHT, estrogen hormone therapy; CHT, combined hormone therapy.