Lumpectomy, radiation therapy (RT), and tamoxifen v lumpectomy, RT, and placebo to prevent first breast cancer events at 5 years‡
| Cumulative incidence of events | ||||
|---|---|---|---|---|
| Events | Tamoxifen | Placebo | Relative event reduction (95% CI) | |
| ‡Not significant. | ||||
| All breast cancer | 8.2% | 13.4% | 37% (17 to 53) | |
| Ipsilateral breast cancer | ||||
| Invasive | 2.1% | 4.2% | 44% (5 to 68) | |
| Non-invasive | 3.9% | 5.1% | 18% (−28 to 47)‡ | |
| Contralateral breast cancer | ||||
| Invasive | 1.8% | 2.3% | 37% (−26 to 69)‡ | |
| Non-invasive | 0.2% | 1.1% | 78% (19 to 96) | |