Table 2.
Univariate linear mixed models predicting log(average FES SUV), with random intercept to account for patients with multiple scans. In the sensitivity analysis, patients with concurrent chemotherapy and/or sites of apparent ER loss without FES uptake above background are excluded. Associations with p < 0.05 noted in italic type
| All eligible scans N=312 scans except where noted | Sensitivity analysis N=203 except where noted | |||||
|---|---|---|---|---|---|---|
| Factor | N Scans | Ratio of mean FES SUV versus factor* | p-value for factor effect | N Scans | Ratio of mean FES SUV versus factor* | p-value for factor effect |
| Patient Characteristics | ||||||
| Age | 1.05 (10 years older) | 0.18 | 1.02 | 0.69 | ||
| Male sex | 1.16 | 0.38 | 1.01 | 0.94 | ||
| Pre-menopausal (female only) | 298 | 1.08 | 0.42 | 194 | 1.00 | 0.98 |
| Advanced (vs early) | 1.11 | 0.62 | 1.34 | 0.18 | ||
| HER2-positive tumor | 293 | 0.89 | 0.22 | 194 | 0.86 | 0.13 |
| Any negative sites | 311 | 0.44 | <0.001 | -- | -- | |
| BMI (kg/m2)** | 1.11 (15% higher) | <0.001 | 1.14 | <0.001 | ||
| Prior Therapy | ||||||
| Prior chemotherapy | 298 | 1.14 | 0.16 | 196 | 1.23 | 0.05 |
| Prior radiation | 297 | 0.93 | 0.37 | 195 | 1.07 | 0.52 |
| Prior tamoxifen | 301 | 1.08 | 0.37 | 197 | 1.12 | 0.20 |
| Concurrent chemotherapy | 306 | 0.77 | 0.02 | -- | -- | |
| Blood Assays | ||||||
| Serum estradiol ≥ 30 pg/mL | 309 | 1.04 | 0.58 | 201 | 0.94 | 0.47 |
| Testosterone ≥ 0.5 ng/mL | 296 | 1.17 | 0.05 | 190 | 0.93 | 0.44 |
| Albumin (g/dL) | 280 | 0.95 (0.3 g/dL higher) | 0.17 | 178 | 0.95 | 0.13 |
| Serum SHBG (nM)*** | 284 | 0.91 (~20 nM higher) | <0.001 | 183 | 0.92 | 0.009 |
| FES metabolism (% at 20 min)**** | 278 | 0.96 (10% pts higher) | 0.19 | 177 | 0.97 | 0.39 |
| FES characteristics for Imaging | ||||||
| Dose (mCi) | 0.98 (0.5 mCi higher) | 0.46 | 0.99 | 0.80 | ||
| Specific activity (Ci/mMol)** | 267 | 1.02 (2x higher) | 0.49 | 168 | 1.03 | 0.34 |
| FES injected per patient weight (nmol/kg)** | 267 | 0.97 (2x higher) | 0.20 | 168 | 0.95 | 0.16 |
| SHBG (% binding) | 293 | 0.91 (10% pts higher) | <0.001 | 186 | 0.91 | 0.002 |
*
Mean FES SUV for all patients with factor versus those without. For continuous measures that ratio is listed as a function of the listed change in the factor, given in parentheses.
**
log transformation
***
square root transformation
****
Percent of total blood activity present as FES at 20 minutes after injection determined by HPLC