Table 1.
Patient demographics and disease characteristics at time of FES PET scan
| Characteristics | N = 56 | % |
|---|---|---|
| Age, years | ||
| Median | 55.5 | |
| Range | 23–74 | |
| < 55 years | 25 | 44.6 |
| ≥ 55 years | 31 | 55.4 |
| Menopausal status | ||
| Premenopausal a | 14 | 25.0 |
| Postmenopausal | 42 | 75.0 |
| Disease-free interval b | ||
| > 5 y | 31 | 55.4 |
| ≤ 5 y | 22 | 39.3 |
| Histology of primary breast cancer | ||
| IDC | 49 | 87.5 |
| ILC | 7 | 12.5 |
| Hormone-receptor status | ||
| ER-positive and PR-positive | 46 | 82.1 |
| ER-positive and PR-negative | 10 | 17.9 |
| Metastatic sites | ||
| Nonvisceral | 30 | 53.6 |
| Bone | 37 | 66.1 |
| Bone-only | 12 | 21.4 |
| Visceral disease | 26 | 46.4 |
| Any lung | 13 | 23.2 |
| Pleural | 7 | 12.5 |
| Peritoneum | 1 | 1.8 |
| Ovarian | 2 | 3.6 |
| Liver | 6 | 7.0 |
| No. of disease sites | ||
| 1 | 18 | 32.1 |
| 2 | 20 | 35.8 |
| ≥ 3 | 18 | 32.1 |
| De novo metastatic disease | 3 | 5.4 |
| Lines of therapy prior to palbociclib | ||
| 0 | 38 | 67.9 |
| 1 | 9 | 16.1 |
| 2 | 4 | 7.1 |
| ≥ 3 | 5 | 8.9 |
| Prior ET for metastatic disease | ||
| None | 43 | 76.8 |
| Yes | 13 | 23.2 |
| Prior ET type for metastatic disease | ||
| Antiestrogen ± LH-RH analog | 8 | 14.3 |
| Aromatase inhibitor ± LH-RH analog | 9 | 16.1 |
| Prior chemotherapy for metastatic disease | ||
| None | 43 | 76.8 |
| Yes | 13 | 23.2 |
| Endocrine therapy following FES PET | ||
| palbociclib + Aromatase inhibitor | 19 | 33.9 |
| palbociclib + fulvestrant | 37 | 66.1 |
| Outcome | ||
| CR | 3 | 5.4 |
| PR | 6 | 10.7 |
| SD | 34 | 60.7 |
| PD | 13 | 23.2 |
| Clinical benefit | ||
| None | 13 | 23.2 |
| Yes | 43 | 76.8 |
| PFS | ||
| Events | 34 | 60.7 |
| Censored | 22 | 39.3 |
| With negative 18F-FES lesions | ||
| None | 46 | 82.1 |
| Yes | 10 | 17.9 |
a For premenopausal women, palbociclib combination with endocrine therapy was given upon the administration of gonadotropin-releasing hormone agonist
b Patients with stage IV breast cancer at initial diagnosis were excluded (N = 3)
Abbreviations: IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; ER, estrogen receptor; PR, progesterone receptor; ET, endocrine therapy; CR, complete responses; PR, partial responses; SD, stable disease; PD, progressive disease; PFS, progression-free survival