Table 1.

Distribution of selected characteristics among controls and cases

CharacteristicsControls (n = 449)Ductal (n = 494)Lobular (n = 307)Ductal-lobular (n = 187)
n (%)n (%)n (%)n (%)
Age, y
 55–59130 (28.9)137 (27.7)90 (29.3)64 (34.2)
 60–64117 (26.1)126 (25.5)78 (25.4)49 (26.2)
 65–69109 (24.3)123 (24.9)77 (25.1)41 (21.9)
 70–7493 (20.7)108 (21.9)62 (20.2)33 (17.7)
Race/ethnicity
 Non-Hispanic White404 (90.0)447 (90.5)287 (93.5)169 (90.4)
 African American8 (1.8)10 (2.0)8 (2.6)4 (2.1)
 Asian/Pacific Islander9 (2.0)15 (3.0)3 (1.0)6 (3.2)
 Native American10 (2.2)12 (2.5)3 (1.0)1 (0.5)
 Hispanic White18 (4.0)10 (2.0)6 (1.9)7 (3.8)
Education
 Less than high school23 (5.1)35 (7.1)19 (6.2)7 (3.7)
 High school graduate120 (26.7)135 (27.3)79 (25.7)43 (23.0)
 Some college/technical school173 (38.6)176 (35.6)96 (31.3)70 (37.5)
 College graduate133 (29.6)148 (30.0)113 (36.8)67 (35.8)
First-degree family history of breast cancer
 No365 (84.3)368 (78.6)229 (76.3)138 (75.4)
 Yes68 (15.7)100 (21.4)71 (23.7)45 (24.6)
 Missing162674
Number of pregnancies resulting in a live birth
 None35 (7.8)65 (13.2)44 (14.3)29 (15.6)
 141 (9.2)58 (11.7)34 (11.1)20 (10.7)
 2156 (34.7)137 (27.7)97 (31.6)60 (32.3)
 ≥3217 (48.3)234 (47.4)132 (43.0)77 (41.4)
 Missing0001
BMI, kg/m2
 <23.4112 (25.1)123 (25.1)90 (29.6)59 (31.9)
 23.4–26.4115 (25.7)120 (24.5)61 (20.1)45 (24.3)
 26.5–31.0111 (24.8)118 (24.1)93 (30.6)48 (26.0)
 ≥31.1109 (24.4)129 (26.3)60 (19.7)33 (17.8)
 Missing2432
Recency of alcohol consumption
 Never users169 (38.0)168 (35.1)102 (33.6)68 (37.2)
 Former users68 (15.3)68 (14.2)35 (11.5)30 (16.4)
 Current users208 (46.7)243 (50.7)167 (54.9)85 (46.4)
 <1 drinks/day43 (20.7)54 (22.2)30 (18.0)17 (20.0)
 ≥1 drink/day165 (79.3)189 (77.8)137 (82.0)68 (80.0)
 Missing41534
Type of menopause
 Natural258 (57.5)333 (67.4)205 (66.8)132 (70.6)
 Induced76 (16.9)61 (12.4)41 (13.3)30 (16.0)
 Simple hysterectomy115 (25.6)100 (20.2)61 (19.9)25 (13.4)
Age at menopause, y
 <4556 (17.7)48 (12.7)17 (7.6)11 (7.5)
 45–54202 (63.7)242 (64.2)154 (68.4)101 (68.2)
 ≥5559 (18.6)87 (23.1)54 (24.0)36 (24.3)
 Missing1321178239
n (%)n (%)n (%)n (%)
Years between age at menopause and reference age
 <881 (25.6)94 (25.0)59 (26.2)43 (29.1)
 8–1482 (25.9)126 (33.4)81 (36.0)53 (35.8)
 15–2180 (25.2)97 (25.7)53 (23.6)40 (27.0)
 ≥2274 (23.3)60 (15.9)32(14.2)12 (8.1)
Age at first use of any type of menopausal HT, y
 <45105 (28.8)82 (21.4)40 (15.5)27 (16.6)
 45–54202 (55.5)239 (62.4)169 (65.8)108 (66.2)
 ≥5557 (15.7)62 (16.2)48 (18.7)28 (17.2)
 Missing851115024
Timing of first use of HT in relation to age at menopause
 Before menopause78 (31.5)96 (34.2)67 (35.8)43 (33.3)
 Same year as menopause103 (41.7)95 (33.8)62 (33.2)47 (36.4)
 1–4 y after menopause34 (13.8)60 (21.3)40 (21.4)26 (20.2)
 ≥5 y after menopause32 (13.0)30 (10.7)18 (9.6)13 (10.1)
 Missing20221312058
Recency of menopausal HT use
 Never87 (19.4)117 (23.8)51 (16.6)25 (13.4)
 Former125 (27.8)102 (20.7)54 (17.6)34 (18.2)
 Current unopposed estrogen142 (31.6)121 (24.6)80 (26.1)42 (22.4)
 Current E + P95 (21.2)152 (30.9)122 (39.7)86 (46.0)
 Missing0200
Duration of HT use, y
 Never87 (19.4)117 (23.8)51 (16.6)25 (13.4)
 <135 (7.8)34 (6.7)19 (6.2)12 (6.4)
 1–475 (16.7)68 (13.8)44 (14.3)32 (17.1)
 5–987 (19.4)71 (14.4)70 (22.8)34 (18.2)
 10–1453 (11.8)94 (19.0)61 (19.9)50 (26.7)
 ≥15112 (24.9)110 (22.3)62 (20.2)34 (18.2)