Table 2.
Phase III clinical trials targeting ER for breast cancer prevention.
| Trial | Interventions | Patient Characteristics | Results |
|---|---|---|---|
| Selective estrogen receptor modulators (SERMs) | |||
| Tamoxifen * | |||
| Royal Marsden trial (49, 52) | Tamoxifen 20 mg vs. Placebo | 2,471 High-risk women | Reduced ER-positive BC by 39% |
| NSABP, P-1 trial (44, 53) | Tamoxifen 20 mg vs. Placebo | 13,388 High-risk women | Reduced ER-positive BC by 62% |
| Italian trial (50, 54) | Tamoxifen 20 mg vs. Placebo | 5,408 Normal-risk women with hysterectomy | Reduced ER-positive BC by 69% |
| IBIS-I trial (51, 55) | Tamoxifen 20 mg vs. Placebo | 7,154 High-risk women | Reduced ER-positive BC by 34% |
| HOT study trial (59) | Tamoxifen 5 mg vs. Placebo | 1884 Postmenopausal women on hormone replacement therapy | Reduced ER-positive BC by 68% |
| Raloxifene * | |||
| MORE trial (58, 60) | Raloxifene (60 or 120 mg) vs. Placebo | 7,705 Postmenopausal normal-risk women with osteoporosis | Reduced ER-positive BC by 84% |
| CORE trial (61) | Raloxifene 60 mg vs. Placebo | 5,213 Women from MORE trial | Reduced ER-positive BC by 76% |
| RUTH trial (62) | Raloxifene 60 mg vs. Placebo | 10,101 Postmenopausal women with coronary heart disease | Reduced ER-positive BC by 55% |
| STAR, P-2 trial (63, 64) | Raloxifene 60 mg vs. Tamoxifen 20 mg | 19,747 Postmenopausal High-risk women | No statistical differences in BC incidence between treatments (but fewer non-invasive BC with tamoxifen) |
| Lasofoxifene | |||
| PEARL trial (65) | Lasofoxifene (0.25 or 0.5 mg) vs. Placebo | 8,556 Postmenopausal women with osteoporosis | Reduced ER-positive BC by 83% with 0.5 mg dose |
| Arzoxifene | |||
| Generations trial (66) | Arzoxifene 20 mg vs. placebo | 9,354 Postmenopausal women with osteoporosis | Reduced ER-positive BC by 70% |
| Aromatase Inhibitors (AIs) | |||
| Exemestane | |||
| MAP.3 trial (67) | Exemestane 25 mg vs. Placebo | 4,560 Postmenopausal high-risk women | Reduced ER-positive BC by 74% |
| Anastrozole | |||
| IBIS-II trial (68) | Anastrozole 1 mg vs. Placebo | 3,864 Postmenopausal high-risk women | Reduced ER-positive BC by 54% |
| Letrozole | |||
| LIBER trial (NCT00673335) | Letrozole 2.5 mg vs. Placebo | 170 Postmenopausal BRCA1/2 carriers with or without previous BC diagnosis | Results expected 2023 |
*
FDA approved for breast cancer prevention.