To develop ligands for imaging breast tumors, [18F]fluoro analogue of tamoxifen and [18F]fluoroalanine were radiosynthesized. In vivo biodistribution studies were performed in mammary tumor-bearing rats. In studies on the biodistribution of an [18F]fluoro analogue of tamoxifen, tumor uptake decreased when rats were pretreated with diethylstilbestrol (DES), suggesting that tracer uptake in tumors was receptor-mediated. An estrogen receptor assay indicated that tumors have a receptor density of 7.5 fmol/mg protein. Studies of the distribution of [18F]fluoroalanine in tissue showed that the tumor-to-tissue ratio increases as a function of time. Positron emission tomography (PET) images of tumor-bearing rats demonstrated that tumors can be visualized 1 h after rats are injected with an [18F]fluoro analogue of tamoxifen. PET imaging of pigs after injection of 10 mCi of [18F]fluoro analogue of tamoxifen showed uterine uptake that could be blocked by DES (50 mg). The findings suggest that both radiotracers are useful for imaging breast tumors.

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BackgroundPrevious studies have reported that higher serum uric acid (SUA) levels are associated with higher bone mineral density (BMD) in men and postmenopausal women, and lower risk of fragility fracture in men. However, whether this association is also present in patients with rheumatoid arthritis (RA) has not yet been investigated.ObjectivesTo examine the association of SUA levels with BMD and osteoporosis in postmenopausal women with RA.MethodsWe retrospectively evaluated 447 postmenopausal female RA patients (mean age 61.1 years) who underwent measurement of L1–4, femoral neck, and total hip BMD using dual energy X-ray absorptiometry, in addition to SUA levels at a university rheumatology centre in South Korea between 2004 and 2017. Osteoporosis was defined as a T-score of ≤−2.5 according to the World Health Organisation classification.ResultsThe median (interquartile range) SUV level was 4 (3.3–4.8) mg/dL. The mean (±SD) L1–4, femoral neck, and total hip BMD were 0.93±0.16 g/cm2, 0.75±0.12 g/cm2, and 0.81±0.12 g/cm2, respectively, and the frequencies of osteoporosis in the spine, hip, and either site were 25.6%, 15.9%, and 32.5%, respectively. SUA levels were positively correlated with L1–4 (ρ=0.102, p=0.032), femoral neck (ρ=0.123, p=0.01), and total hip BMD values (ρ=0.146, p=0.002) and body mass index (ρ=0.231, p<0.001), and negatively correlated with glomerular filtration rate (ρ=−0.363, p<0.001) in Spearman correlation analysis. In multivariable linear regression models adjusted for confounding factors, SUA levels showed a significant positive association with femoral neck BMD (β=0.0099, p=0.015) and total hip BMD (β=0.0118, p=0.01) but not with L1–4 BMD (β=0.0086, p=0.159) as shown in table 1. In addition, multivariable logistic analysis revealed that the third (OR=0.44, p=0.038) and fourth SUA quartiles (OR=0.37, p=0.021) were associated with lower risk of hip osteoporosis, as compared with the first SUA quartile. However, this association was not observed in lumbar spine osteoporosis.Abstract AB1000 – Table 1Linear regression models evaluating the association between serum uric acid levels and bone mineral density in postmenopausal women with rheumatoid arthritisIndependent variablesDependent variablesUnivariable modelMultivariable model Unstandardized β (SE)p-value*Unstandardized β (SE)p-value Serum uric acid, mg/dLFemoral neck BMD0.0125 (0.0045)0.0060.0099 (0.004)0.015Serum uric acid, mg/dLTotal hip BMD0.0138 (0.0048)0.0040.0118 (0.0045)0.01Serum uric acid, mg/dLL1–4 BMD0.0127 (0.0063)0.0440.0086 (0.0061)0.159*Estimated using stepwise multivariable linear regression models adjusting for age, BMI, DAS28-ESR, cumulative GCs dose, disease duration and eGFRConclusionsHigher SUA levels were associated with a reduced risk of low BMD and osteoporosis at hip in postmenopausal women with RA, but no significant association between SUA levels and lumbar spine BMD was found. Our data suggests that uric acid may act as a protective factor against hip bone loss in RA patients.Disclosure of InterestNone declared

10626 Background: Approximately 50% of pts with metastatic breast carcinoma develop hepatic involvement during the course of their disease. Their median survival is 1–14 months (mo). Systemic paclitaxel has good anti-tumor activity against breast carcinoma and is safe. We sought to prospectively determine the safety and anti-tumor activity of HIA paclitaxel therapy. Methods: Ten pts with breast carcinoma and dominant liver metastases received monthly inpatient 24 hr-continuous HIA infusions of paclitaxel at 200 mg/m2 through intra-arterial catheters placed via percutaneous transfemoral approach. WHO tumor assessment guidelines were used. Results: Nine pts enrolled in this study had infiltrating ductal carcinoma and their median age at the time of treatment was 51 years. The group had received a mean of 3.8 previous treatment regimens including adjuvant regimens. Therapy was well tolerated. Fifty-six courses were delivered. Mean hospital stay was 3 days. No procedure related complications were observed. Most common treatment related toxicities included leukopenia, fatigue, nausea, and vomiting. Three pts attained partial responses (50% decrease in tumors) lasting 6, 7, and 48 months whereas in 4 others disease stabilization lasted 5 to 9 mo. One pt underwent liver resection and remained NED for 48 mo. Eight pts had received prior systemic taxane therapy alone or in combination with other cytotoxics (3 adjuvant; 5 palliative). However, no association between previous taxane exposure and clinical efficacy of this regimen was not established. Conclusions: Hepatic arterial therapy with paclitaxel at this dose and schedule is safe and well tolerated and has reasonable anti-tumor activity against breast carcinoma involving the liver. Previous taxane exposure does not hamper the potential benefit of this approach. This regimen deserves further investigation alone or in combination with targeted strategies in patients with dominant liver involvement from breast carcinoma. No significant financial relationships to disclose.