Table 2.
Breast cancer risk factors by CYP17 genotype (BRCA1 and BRCA2 mutation carriers excluded)
| Factor | Premenopausal (n = 529) | Postmenopausal (n = 150) | Pooled (pre- and postmenopausal) (n = 679) | |||
| CYP17 genotype... | A1/A1 | A1/A2 and A2/A2 | A1/A1 | A1/A2 and A2/A2 | A1/A1 | A1/A2 and A2/A2 |
| Age at menarche | ||||||
| <13 years | 95 (48) | 112 (34)** | 28 (42) | 35 (42) | 123 (46) | 147 (36)*** |
| ≥13 years | 105 (52) | 216 (66) | 38 (58) | 49 (58) | 143 (54) | 265 (64) |
| Age at first birth | ||||||
| <25 years | 52 (37) | 93 (40) | 37 (61) | 40 (54) | 89 (44) | 133 (43) |
| ≥25 years | 89 (63) | 142 (60) | 24 (39) | 34 (46) | 113 (56) | 176 (57) |
| Ever use oral contraceptives | ||||||
| No | 12 (6) | 20 (6) | ||||
| Yes | 189 (94) | 308 (94) | ||||
| Family history of breast cancer | ||||||
| No | 189 (94) | 309 (94) | 60 (91) | 78 (93) | 249 (93) | 387 (94) |
| Yes | 12 (6) | 19 (6) | 6 (9) | 6 (7) | 18 (7) | 25 (6) |
| Age at menopause | ||||||
| <48 years | 40 (61) | 45 (54) | ||||
| ≥48 years | 26 (39) | 39 (46) | ||||
| Ever use HRT | ||||||
| No | 28 (42) | 33 (48) | ||||
| Yes | 38 (58) | 51 (61) | ||||
Data are presented as n (%). **P = 0.002, ***P = 0.006. Information on difficulty getting pregnant was unavailable. HRT, hormone replacement therapy.