| Study (n) |
Agent, Dose |
Median Followup (mo.) |
Breast Cancer Types |
Cases of Breast Cancer (n) |
Breast Cancer Rate/1,000 woman-years |
Relative Risk (95% CI) |
|||
|---|---|---|---|---|---|---|---|---|---|
| Placebo | Treatment | Placebo | Treatment | P value | |||||
| Royal Marsden (19) (n=2,471,ages 30-70) | Tamoxifen, 20 mg/d | 70 | All types | 36 | 34 | 5.02 | 4.72 | 0.8 | 0.94 (0.59-1.43) |
| Italian Study (21,23) (n=5,408,ages 35-70) | Tamoxifen, 20 mg/d | 46 | All types | 22 | 19 | 2.32 | 2.12 | 0.64 | 0.873 (0.62-2.14) |
| ER+ | 10 | 8 | NA | NA | NA | NA | |||
| 81.2 | All types | 45 | 34 | NA | NA | 0.215 | HR4 0.75 (0.48-1.18) |
||
| Breast Cancer Prevention Trial (20) (n=13,388,ages 35+) | Tamoxifen, 20 mg/d | 54.6 | Invasive | 175 | 89 | 6.82 | 3.42 | <0.00001 | 0.51 (0.39-0.66) |
| ER+ | 130 | 41 | NA | NA | NA | 0.31 (0.22-0.45) |
|||
| Noninvasive | 69 | 35 | 2.72 | 1.42 | <0.002 | 0.50 (0.33-0.77) |
|||
| Multiple Outcomes of Raloxifene Evaluation (22,25) (n=7,705, median age 66.5) | Raloxifene, 60 or 120 mg/d | 40 | All types | 32 | 22 | 4.3 | 1.5 | <0.001 | 0.35 (0.21-0.58) |
| Invasive | 27 | 13 | 3.6 | 0.9 | <0.001 | 0.24 (0.13-0.44) |
|||
| ER+ | 20 | 4 | NA | NA | NA | 0.10 (0.04-0.24) |
|||
| 48 | All types | 44 | 33 | NA | NA | NA | 0.38 (0.24-0.58) |
||
| Invasive | 39 | 22 | NA | NA | NA | 0.28 (0.17-0.46) |
|||
| ER+ | 31 | 10 | NA | NA | NA | 0.16 (0.09-0.30) |
|||
1ER+, estrogen-receptor positive; CI, Confidence Interval; NA, Data not available.
2Data from reference (23).
3Calculated by authors.
4HR, hazard ratio, the estimate of relative risk at a given time.