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... | A 1/A 1 | A 1/A 2 and A 2/A 2 | A 1/A 1 | A 1/A 2 and A 2/A 2 | A 1/A 1 | A 1/A 2 and A 2/A 2 |
Age at menarche | Â | Â | Â | Â | Â | Â |
   <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 | Â | Â | Â | Â | Â | Â |
   <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 | Â | Â | Â | Â | Â | Â |
   No | 12 (6) | 20 (6) |  |  |  |  |
   Yes | 189 (94) | 308 (94) |  |  |  |  |
Family history of breast cancer | Â | Â | Â | Â | Â | Â |
   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 | Â | Â | Â | Â | Â | Â |
   <48 years |  |  | 40 (61) | 45 (54) |  |  |
   ≥48 years |  |  | 26 (39) | 39 (46) |  |  |
Ever use HRT | Â | Â | Â | Â | Â | Â |
   No |  |  | 28 (42) | 33 (48) |  |  |
   Yes |  |  | 38 (58) | 51 (61) |  |  |