Table 2.
Treatment summary.
| Prior treatment | |
| None | 12 |
| Chemotherapy alone | 1 |
| ET alone | 4 |
| ET and chemotherapy | 11 |
| ET, chemotherapy, and CDK 4/6 inhibitor | 3 |
| ET and CDK 4/6 inhibitor | 4 |
| ET, chemotherapy, and mTOR inhibitor | 3 |
| ET, CDK 4/6 inhibitor, and mTOR inhibitor | 1 |
| ET, chemotherapy, CDK 4/6 inhibitor, and AKT inhibitor | 2 |
| ET, mTOR inhibitor, and chemotherapy | 1 |
| ET, chemotherapy, mTOR inhibitor, and trastuzumab* | 1 |
| ET during study and response within 6 months | |
| Aromatase inhibitor (2 PD, 1 SD, 6 PR) | 9 |
| Tamoxifen and AKT inhibitor (1 SD) | 1 |
| Aromatase inhibitor and CDK 4/6 inhibitor (5 PD, 8 SD, 7 PR) | 20 |
| Fulvestrant and CDK 4/6 inhibitor (5 PD, 1 SD) | 6 |
| Aromatase inhibitor and mTOR inhibitor (3 PD) | 3 |
| Aromatase inhibitor, gonadotropin-releasing hormone agonist, and mTOR inhibitor (1 SD) | 1 |
| Aromatase inhibitor, CDK 4/6 inhibitor, and mTOR inhibitor (1 PR) | 1 |
| Aromatase inhibitor, gonadotropin-releasing hormone agonist (1 PR) | 1 |
| Aromatase inhibitor, CDK 4/6 inhibitor, and gonadotropin-releasing hormone agonist (1 PR) | 1 |
ET endocrine therapy, PD progressive disease, SD stable disease, PR partial response, AKT protein kinase B.
*Patient had ER+/PR–/HER2+ primary breast cancer and developed ER+/PR+/HER2–metastatic disease several years later.