Table 1.
Distribution of selected characteristics among controls and cases
| Characteristics | Controls (n=449) | Ductal (n=494) | Lobular (n=307) | Ductal-lobular (n=187) |
|---|---|---|---|---|
| n (%) | n (%) | n (%) | n (%) | |
| Age (years) | ||||
| 55–59 | 130 (28.9) | 137 (27.7) | 90 (29.3) | 64 (34.2) |
| 60–64 | 117 (26.1) | 126 (25.5) | 78 (25.4) | 49 (26.2) |
| 65–69 | 109 (24.3) | 123 (24.9) | 77 (25.1) | 41 (21.9) |
| 70–74 | 93 (20.7) | 108 (21.9) | 62 (20.2) | 33 (17.7) |
| Race/ethnicity | ||||
| Non-Hispanic White | 404 (90.0) | 447 (90.5) | 287 (93.5) | 169 (90.4) |
| African American | 8 (1.8) | 10 (2.0) | 8 (2.6) | 4 (2.1) |
| Asian/Pacific Islander | 9 (2.0) | 15 (3.0) | 3 (1.0) | 6 (3.2) |
| Native American | 10 (2.2) | 12 (2.5) | 3 (1.0) | 1 (0.5) |
| Hispanic White | 18 (4.0) | 10 (2.0) | 6 (1.9) | 7 (3.8) |
| Education | ||||
| Less than high school | 23 (5.1) | 35 (7.1) | 19 (6.2) | 7 (3.7) |
| High school graduate | 120 (26.7) | 135 (27.3) | 79 (25.7) | 43 (23.0) |
| Some college/technical school | 173 (38.6) | 176 (35.6) | 96 (31.3) | 70 (37.5) |
| College graduate | 133 (29.6) | 148 (30.0) | 113 (36.8) | 67 (35.8) |
| First-degree family history of breast cancer | ||||
| No | 365 (84.3) | 368 (78.6) | 229 (76.3) | 138 (75.4) |
| Yes | 68 (15.7) | 100 (21.4) | 71 (23.7) | 45 (24.6) |
| Missing | 16 | 26 | 7 | 4 |
| Number of pregnancies resulting in a live birth | ||||
| None | 35 (7.8) | 65 (13.2) | 44 (14.3) | 29 (15.6) |
| 1 | 41 (9.2) | 58 (11.7) | 34 (11.1) | 20 (10.7) |
| 2 | 156 (34.7) | 137 (27.7) | 97 (31.6) | 60 (32.3) |
| ≥3 | 217 (48.3) | 234 (47.4) | 132 (43.0) | 77 (41.4) |
| Missing | 0 | 0 | 0 | 1 |
| BMI (kg/m2) | ||||
| <23.4 | 112 (25.1) | 123 (25.1) | 90 (29.6) | 59 (31.9) |
| 23.4–26.4 | 115 (25.7) | 120 (24.5) | 61 (20.1) | 45 (24.3) |
| 26.5–31.0 | 111 (24.8) | 118 (24.1) | 93 (30.6) | 48 (26.0) |
| ≥31.1 | 109 (24.4) | 129 (26.3) | 60 (19.7) | 33 (17.8) |
| Missing | 2 | 4 | 3 | 2 |
| Recency of alcohol consumption | ||||
| Never users | 169 (38.0) | 168 (35.1) | 102 (33.6) | 68 (37.2) |
| Former users | 68 (15.3) | 68 (14.2) | 35 (11.5) | 30 (16.4) |
| Current users | 208 (46.7) | 243 (50.7) | 167 (54.9) | 85 (46.4) |
| <1 drinks/day | 43 (20.7) | 54 (22.2) | 30 (18.0) | 17 (20.0) |
| ≥1 drink/day | 165 (79.3) | 189 (77.8) | 137 (82.0) | 68 (80.0) |
| Missing | 4 | 15 | 3 | 4 |
| Type of menopause | ||||
| Natural | 258 (57.5) | 333 (67.4) | 205 (66.8) | 132 (70.6) |
| Induced | 76 (16.9) | 61 (12.4) | 41 (13.3) | 30 (16.0) |
| Simple hysterectomy | 115 (25.6) | 100 (20.2) | 61 (19.9) | 25 (13.4) |
| Age at menopause (years) | ||||
| <45 | 56 (17.7) | 48 (12.7) | 17 (7.6) | 11 (7.5) |
| 45–54 | 202 (63.7) | 242 (64.2) | 154 (68.4) | 101 (68.2) |
| ≥55 | 59 (18.6) | 87 (23.1) | 54 (24.0) | 36 (24.3) |
| Missing | 132 | 117 | 82 | 39 |
| Age at first use of any type of menopausal hormone therapy (years) | ||||
| <45 | 105 (28.8) | 82 (21.4) | 40 (15.5) | 27 (16.6) |
| 45–54 | 202 (55.5) | 239 (62.4) | 169 (65.8) | 108 (66.2) |
| ≥55 | 57 (15.7) | 62 (16.2) | 48 (18.7) | 28 (17.2) |
| Missing | 85 | 111 | 50 | 24 |
| Timing of first use of hormone therapy in relation to age at menopause | ||||
| Before menopause | 78 (31.5) | 96 (34.2) | 67 (35.8) | 43 (33.3) |
| Same year as menopause | 103 (41.7) | 95 (33.8) | 62 (33.2) | 47 (36.4) |
| 1–4 years after menopause | 34 (13.8) | 60 (21.3) | 40 (21.4) | 26 (20.2) |
| ≥5 years after menopause | 32 (13.0) | 30 (10.7) | 18 (9.6) | 13 (10.1) |
| Missing | 202 | 213 | 120 | 58 |
| Recency of menopausal hormone therapy use | ||||
| Never | 87 (19.4) | 117 (23.8) | 51 (16.6) | 25 (13.4) |
| Former | 125 (27.8) | 102 (20.7) | 54 (17.6) | 34 (18.2) |
| Current unopposed estrogen | 142 (31.6) | 121 (24.6) | 80 (26.1) | 42 (22.4) |
| Current estrogen+progestin | 95 (21.2) | 152 (30.9) | 122 (39.7) | 86 (46.0) |
| Missing | 0 | 2 | 0 | 0 |
| Timing of age at reference in relation to age at menopause (years) | ||||
| <8 | 81 (25.6) | 94 (25.0) | 59 (26.2) | 43 (29.1) |
| 8–14 | 82 (25.9) | 126 (33.4) | 81 (36.0) | 53 (35.8) |
| 15–21 | 80 (25.2) | 97 (25.7) | 53 (23.6) | 40 (27.0) |
| 22+ | 74 (23.3) | 60 (15.9) | 32(14.2) | 12 (8.1) |
| Missing | 132 | 117 | 82 | 39 |
| Duration of hormone therapy use (years) | ||||
| Never | 87 (19.4) | 117(23.8) | 51(16.6) | 25(13.4) |
| <1 | 35 (7.8) | 34(6.7) | 19(6.2) | 12(6.4) |
| 1–4 | 75 (16.7) | 68 (13.8) | 44 (14.3) | 32 (17.1) |
| 5–9 | 87 (19.4) | 71 (14.4) | 70 (22.8) | 34 (18.2) |
| 10–14 | 53 (11.8) | 94 (19.0) | 61 (19.9) | 50 (26.7) |
| ≥15 | 112 (24.9) | 110 (22.3) | 62 (20.2) | 34 (18.2) |