Comparison of expert treatment recommendations versus community healthcare providers: Analysis from an online decision support tool for metastatic breast cancer.

1053 Background: Management of metastatic breast cancer (MBC) is quickly evolving. Beyond hormone receptor (HR) status, a growing list of molecular markers are used to refine individualized systemic treatment (Tx). However, the number of options increases the complexity of Tx decision-making for healthcare professionals (HCPs). Here, we report an analysis of discordance between expert Tx recommendations vs HCPs from an online Interactive Decision Support Tool (IDST). Methods: Five breast cancer experts provided Tx recommendations for 59 unique MBC case scenarios where systemic therapy was indicated. Case scenarios were defined by key characteristics, including HR status, previous Tx, prior duration of response, and actionable biomarkers. After HCPs (n = 91) selected specific patient (pt) criteria and their intended Tx, the IDST showed the breast cancer experts’ recommendations, and HCPs were then asked whether seeing the recommendations changed their intended Tx plan. Experts’ recommendations were compared with that of HCPs to assess for concordance or discordance. Results: For first-line (1L) HR+/HER2- MBC, all experts (100%) recommended endocrine therapy with CDK4/6 inhibitor vs 38% of HCPs. For 1L HER2+ MBC, 62.5% concordance was observed with HCPs selecting expert recommended docetaxel, trastuzumab, and pertuzumab (THP). For 1L therapy for triple negative breast cancer (TNBC) based on BRCA1/2mutation and/or PD-L1 status, 44% of HCPs indicated they were uncertain of optimal Tx. Discordant findings were also observed for pretreated pts. For pretreated HR+/HER2- MBC, <50% of HCPs selected expert-recommended elacestrant for ESR1 mutant disease and chemotherapy (CT) if <12 months of prior response to 1L Tx vs 100% of experts. Moreover, 2 out of 5 HCPs agreed with experts in recommending T-DXd in pretreated HER2-low MBC. In pretreated HER2+ MBC, 100% of experts chose T-DXd vs 60% of HCPs if previous THP and no brain metastases, and 60% of experts vs 40% of HCPs chose T-DXd if brain metastases. In recurrent TNBC with no actionable biomarkers and ≥2 previous systemic CT, 7% of HCPs selected sacituzumab govitecan vs all experts selecting this Tx or CT not previously received. Overall, 50% and 29% of HCPs indicated expert recommendations changed or confirmed their practice, respectively. Conclusions: Data from an online IDST demonstrate discordance of expert recommendations and community HCPs Tx selection in MBC, which is made challenging by a number of variables that that must be assessed during the care continuum. Expert recommendations in the IDST often reinforced or changed HCP’s Tx plan, highlighting the need for ongoing education and the potential of an online tool to improve optimal Tx decisions for MBC, particularly when HCPs must consider current guidelines and tumor-specific biomarkers across multiple tumor types they may see.