TABLE 1

Patient Characteristics

CharacteristicAll patients, n = 91
Median age (y)61 (range, 33–83)
Sex (n)
 Female90 (99%)
 Male1 (1%)
Median time from primary tumor to metastasis (y)5 (range, 0–22)
Primary tumor immunohistochemistry receptor status
 ER (n)
  Positive85 (97%)
  Negative*3 (3%)
  Unknown*3
 PR (n)
  Positive64 (83%)
  Negative13 (17%)
  Unknown14
 Human epidermal growth factor receptor 2 (n)
  Positive11 (18%)
  Negative50 (82%)
  Unknown30
Second primary breast malignancy17 (19%)
 ER antagonist use before 18F-FES PET (n)
  Median stop duration (wk)5.2 (range, 3–11)
Receptor discordance primary tumor and metastasis
 ER (n)/total patient with known receptor status
  Concordant29/35 (83%)
  Positive to negative5/35 (14%)
  Negative to positive1/35 (3%)
 PR (n)
  Concordant23/29 (79%)
  Positive to negative5/29 (17%)
  Negative to positive1/29 (3%)
 Human epidermal growth factor receptor 2
  Concordant17/18 (94%)
  Positive to negative1/18 (6%)
  Negative to positive0/18 (0%)

  • ↵* Metastatic lesion or secondary primary breast cancer ER-positive on immunohistochemistry.