Table 2. The risk of breast cancer with all histologies and invasive ductal carcinoma following the use of HRT.
| Use of HRT | No of HRT users | No of cases | Breast cancer all types | No of cases | Breast cancer invasive ductal carcinoma |
|---|---|---|---|---|---|
| N=10 874 | N (%) | N=244 | RR (95% CI)a | N=172 | RR (95% CI)a |
| Never | 6566 (60.4) | 110 | 1.00 | 78 | 1.00 |
| Past | 1582 (14.5) | 31 | 1.16 (0.76–1.77) | 16 | 0.85 (0.49–1.50) |
| Current | 2726 (25.1) | 103 | 2.42 (1.81–3.26) | 78 | 2.49 (1.76–3.51) |
| Never HRT | 6566 (60.4) | 110 | 1.00 | 78 | 1.00 |
| Past HRT | 1582 (14.5) | 31 | 1.16 (0.76–1.77) | 16 | 0.85 (0.49–1.50) |
| Oestrogen | 543 (5.0) | 16 | 1.95 (1.15–3.32) | 12 | 2.03 (1.10–3.75) |
| E+ prog-P cyclical | 433 (4.0) | 20 | 3.02 (1.80–5.05) | 15 | 3.10 (1.69–5.67) |
| E+ test-P cyclical | 1054 (9.7) | 32 | 1.94 (1.26–3.00) | 26 | 2.15 (1.31–3.54) |
| E+ test-P continuous | 431 (3.1) | 23 | 4.16 (2.56–6.75) | 17 | 4.10 (2.29–7.30) |
| Current Tibolone | 79 (0.7) | 5 | 4.27 (1.74–10.51) | 4 | 4.89 (1.78–13.42) |
| Current other HRT | 276 (2.5) | 7 | 1.53 (0.67–3.50) | 4 | 1.10 (0.34–3.45) |
E=oestrogen, P=progestin, prog-P=progesterone-like progestin, test-P=testosterone-like progestin.
a
Adjusted for benign breast disease (0, yes; 1, no) and menopausal age (0<55 years; 1.55+ years).