Table 1 Characteristics of the women
Characteristic | All (N = 906) | Controls (N = 453) | Cases (N = 453) |
|---|---|---|---|
Reference age (years)* | 61 (59 to 66) | 61 (59 to 66) | 61 (59 to 66) |
Age at mammogram (years)* | 61 (58 to 65) | 61 (58 to 65) | 60 (58 to 65) |
MHT at mammogram, N (%) | |||
Never | 189 (20.9) | 110 (24.3) | 79 (17.4) |
Current | 432 (47.7) | 217 (47.9) | 215 (47.5) |
Past, 0–2 years since last use | 154 (17.0) | 50 (11.0) | 104 (23.0) |
Past, > 2 years since last use | 131 (14.5) | 76 (16.8) | 55 (12.1) |
Type of MHT at mammogram, N (%) | |||
None | 189 (20.9) | 110 (24.3) | 79 (17.4) |
Oestrogen | 30 (3.3) | 15 (3.3) | 15 (3.3) |
Oestrogens plus progestogens | 490 (54.1) | 233 (51.4) | 257 (56.7) |
Oestrogen plus progesterone or dydrogesterone | 138 (15.2) | 79 (17.4) | 59 (13.0) |
Oestrogen plus progestins | 239 (26.4) | 99 (21.9) | 140 (30.9) |
Both | 113 (12.5) | 55 (12.1) | 58 (12.8) |
Others | 197 (21.7) | 95 (21.0) | 102 (22.5) |
BMI at mammogram (kg/m2)* | 22.9 (21.1 to 25.1) | 22.8 (21.0 to 24.8) | 23.1 (21.3 to 25.4) |
PMD* | 32 (20 to 45) | 31 (17 to 43) | 35 (23 to 49) |
DA (cm2)* | 33 (20 to 47) | 29 (17 to 42) | 35 (23 to 52) |
NDA (cm2)* | 70 (47 to 97) | 72 (49 to 97) | 68 (46 to 96) |
ER and PR status, N (%)** | |||
ER+ and PR+ | 224 (60.6) | ||
ER+ and PR− | 77 (20.8) | ||
ER− and PR+ | 13 (3.5) | ||
ER− and PR− | 56 (15.1) | ||
Family history of breast cancer in first-degree relatives, N (%) | |||
No | 771 (85.1) | 394 (87.0) | 377 (83.2) |
Yes | 135 (14.9) | 59 (13.0) | 76 (16.8) |
Age of menarche (years), N (%) | |||
< 12 | 162 (17.9) | 69 (15.2) | 93 (20.5) |
12 | 244 (26.9) | 125 (27.6) | 119 (26.3) |
> 12 | 500 (55.2) | 259 (57.2) | 241 (53.2) |
Past use of oral contraceptives, N (%) | |||
No | 452 (49.9) | 232 (51.2) | 220 (48.6) |
Yes | 454 (50.1) | 221 (48.8) | 233 (51.4) |
Parity and lactation, N (%)** | |||
Nulliparous | 116 (13.6) | 59 (14.0) | 57 (13.3) |
Parous without lactation | 205 (24.1) | 94 (22.3) | 111 (25.8) |
Parous with lactation for less than 4 months | 246 (28.9) | 123 (29.2) | 123 (28.6) |
Parous with lactation for 4 months or more | 284 (33.4) | 145 (34.4) | 139 (32.3) |