Billar, Julie A.

e12749 Background: Breast cancer (BC) survivors are at higher risk for recurrence or new primary disease and often require complex surveillance imaging. Use of contrast enhanced surveillance imaging modalities with contrast-enhanced digital mammography (CEM) and magnetic resonance imaging (MRI) has increased in recent years. This study evaluates characteristics of those BC survivors who receive contrast enhanced imaging and whether the addition of contrast enhanced imaging affects biopsy outcomes in BC survivors. Methods: An IRB-approved retrospective chart review identified female BC survivors who underwent breast surgery and subsequent surveillance imaging at a single academic center between 2016 and 2025. Surveillance episodes were categorized as mammography alone versus mammography with addition of CEM and/or MRI. Multivariable generalized estimating equations were used to compare patient and tumor characteristics associated with enhanced imaging modality use. Similarly rates of biopsy and cancer were evaluated with enhanced imaging use. Results: A total of 4,050 surveillance imaging episodes in 861 patients were identified and 54 resulted in biopsy-proven malignancy. Mammography alone was performed in 3,459 episodes, while enhanced imaging with CEM or MRI was used in 591 (14.6%) episodes. Use of CEM or MRI for surveillance imaging increased over time. In 2016, surveillance imaging consisted predominantly of mammography alone (93.3%) with 6.6% incorporating MRI or CEM. By 2025, mammography only surveillance decreased to 78.4% while use of MRI or CEM increased to 21.6%. Use of contrast enhanced imaging was associated with higher incidence rate ratios (IRR) for dense breast tissue [IRR 2.33; 95% CI 1.92, 2.82), p < 0.001] and less frequently used among patients aged 65–79 years [IRR 0.60, 95% CI 0.49, 0.74; p < 0.0001] and > = 80 years of age [IRR 0.40; 95% CI 0.24, 0.66; p < 0.001]. Ductal carcinoma in situ (DCIS) (IRR 3.09, p = 0.0061), and immunotherapy use (IRR 2.56, p = 0.0006) also were associated with increased use of CEM/MRI enhanced imaging. Biopsies were performed in 146 (4.2%) mammography alone episodes and 55 (9.3%) enhanced imaging episodes [IRR 2.20; 95% CI 1.63, 2.96; p < 0.001]. Surveillance with mammography yielded malignant biopsy results in 39 (1.1%) episodes, compared with 15 (2.5%) episodes using enhanced imaging [IRR 2.25; 95% CI 1.25, 4.06; p = 0.007). Conclusions: In breast cancer surveillance at our institution, the addition of contrast enhanced imaging modalities were utilized in a minority of surveillance episodes but did increase over time and were higher in patients with dense breasts. CEM or MRI usage demonstrated higher biopsy rates and increased malignancy detection compared with mammography alone, but the incidence of a positive biopsy was low. These findings suggest and are in keeping with 2023 ACR guidelines that enhanced imaging may improve cancer detection in select breast cancer survivors.

639 Background: Large cohort studies have shown a survival benefit with the use of GLP1 receptor agonists (GLP1 RA) in cancer patients. The impact of GLP1 RA usage in breast cancer (BC) and the different subtypes is unknown. To investigate the potential influence of GLP1 RA usage on BC survival, a study was conducted on a large institutional database. Methods: A de-identified institutional database identified newly diagnosed Stage I, II, and III BC patients from 2005 to present and use of GLP1 RA. The study compared survival rates for BC patients with and without GLP1 RA and further stratified by BC subtype [ER+HER2-, HER2+, ER-PR-HER2-(triple negative BC (TNBC))], BMI, and age. Kaplan-Meier survival curves were used to estimate overall survival. This study analyzed de-identified data accessed through Mayo Clinic Platform Discover. Per 45 CFR 46.102, this activity did not require IRB review. Data was extracted using an established privacy-preserving protocol and de-identified via expert determination under the HIPAA Privacy Rule. Raw EHR data and other unreported data cannot be shared due to de-identification parameters. Results: 88015 BC patients were identified, of which 3919 (4.5%) received GLP1 RA. The 5-year survival rate was 98.5% with vs 85.5% without GLP1 RA (p-value <0.0001). The survival benefit persisted for different BMI’s and ages: BMI >30 (98.4% vs 85.1%), >25 (98.4% vs 85.4%), and age <50 (99.5% vs 89.3%) and >50 (98.1% vs 84.8%) [all p<0.0001]. 21770 patients with ER+ disease were identified, of which 1412 (6.5%) received GLP1 RA. The 5-year survival rate was 99.0% vs 87.7% (p-value <0.0001). The survival benefit persisted by BMI and age: BMI >30 (99.0% vs 86.2%), >25 (98.9% vs 87.1%) and age <50 (99.6% vs 90.5%) and >50 (98.7% vs 87.2%) [all p<0.0001]. 3599 patients with HER2+ disease were identified, of which 202 (5.6%) received GLP1 RA. The 5-year survival rate was 99.3% vs 80.1% (p-value <0.0001). The survival benefit persisted by stratification: BMI >30 (100.0% vs 80.0%, p-value <0.0004), and <25 (97.7% vs 76.2%, p-value <0.019), and age <50 (100% vs 87.0%, p-value <0.043) and > 50 (99.0% vs 77.2%, p-value <0.0002). 8389 patients with TNBC disease were identified, of which 360 (4.3%) received GLP1 RA. The 5-year survival rate was 91.0% vs 71.9% (p-value <0.0001). The survival benefit persisted by stratification: BMI >30 (96.4% vs 72.9%, p-value <0.0001), >25 (93.2% vs 71.8%, p-value <0.0001), and age <50 (96.0% vs 73.0%, p-value <0.0028) and >50 (88.9% vs 71.8%, p-value <0.0001). For those TNBC patients who received GLP1 RA, having a BMI >30 conferred a protective effect with a 5-year survival rate was 97.9 vs 89.8% (p-value <0.0014). Conclusions: The study suggests that GLP1-RA improves 5-year survival rates of patients with BC and this applies to all subtypes of BC. These results suggest that further study of the impact of GLP1-RA on BC patients is warranted.