Patients and Scan Characteristics (n = 100 18F-FES PET Scans in 83 Patients)
| Characteristic | Data |
|---|---|
| Mean age ± SD (y) | 59 ± 11 |
| Female (n) | 99 (99%) |
| BC stage at time of 18F-FES PET | |
| Metastatic disease* | 51 (51%) |
| Suspected metastatic disease | 49 (49%) |
| Time from primary tumor diagnosis to 18F-FES PET (y)† | |
| Median | 6 |
| Range | 0–34 |
| BC primary tumor ER expression (n = 94‡) | |
| Positive | 92 (98%) |
| Negative§ | 2 (2%) |
| Histology of primary tumor‖ (n = 87) | |
| Ductal | 64 (74%) |
| Lobular | 21 (24%) |
| Ductolobular | 1 (1%) |
| Micropapillary | 1 (1%) |
| ER expression in BC metastases¶ (n = 31)║ | |
| Positive | 28 (90%) |
| Negative# | 3 (10%) |
| Standard workup before 18F-FES PET | |
| At least 1 conventional technique** | 90 (90%) |
| CT scan | 59 (59%) |
| Bone scintigraphy | 36 (36%) |
| MRI | 23 (23%) |
| 18F-FDG PET | 21 (21%) |
| Biopsy | 29 (29%) |
| Breast lesion†† (n = 29) | 12 (41%) |
| Nonbreast lesion (n = 29) | 17 (59%) |
↵* Ultimately diagnosed with metastatic gastric carcinoma with breast metastases, instead of newly diagnosed metastatic BC (n = 1).
↵† If >1 primary BC, first diagnosis and histologic type of BC was included.
↵‡ In 5/6 unknown cases, metastatic lesion or secondary primary BC ER-positive.
↵§ One patient with ER-negative primary tumor presented with new palpable breast mass with metastases; it was unclear whether this new mass was secondary primary BC or recurrence, and biopsy was not possible. Another patient had mixed ER-negative and ER-positive primary tumor, which was treated as triple-negative BC.
↵‖ If >1 primary BC, first diagnosis and histologic type of BC was included.
↵¶ Metastasis biopsy was not always possible, was not performed, or was not representative; only cytology was available; or data were not available from medical records.
↵# Secondary (primary BC ER-positive).
↵** In 10 cases, standard workup could not or was not performed, for the following reasons: priority was to determine whole-body ER status for subsequent endocrine treatment (n = 4); previous tumor progression was detected only by 18F-FES PET, not by conventional imaging, so conventional imaging was deemed noninformative in present setting (n = 3); there was clinical and biochemical suspicion of tumor progression and presence of 2 different tumor types (n = 1); biopsy was not possible to determine ER status (n = 1); and after completion of chemotherapy, further diagnostic workup was required to clarify origin of cancer metastases (n = 1).
↵†† With or without axillary dissection.