Background: To assess patient reported breast cancer (BC) specific quality of life (QOL) in HR+/HER2- advanced or metastatic BC (ABC/MBC). Methods: Patients (N=2,352) were recruited into a cross-sectional survey from centers in 5 major EU countries and the US. BC specific QOL was reported by a subset of patients (n=739) using the Functional Assessment of Cancer Therapy Breast (FACT-B) tool, which includes the FACT General (FACT-G) (4 subscales assessing physical [PWB], social [SWB], emotional [EWB], and functional [FWB] wellbeing) and the BC specific subscale (BCS). Results are reported for the overall cohort, by therapy and sites of metastases. Significance was assessed using Mann-Whitney U and Kruskal-Wallis tests. Results: Patients’ mean (SD) age was 65.2 (10.6). Most patients (82.7%, n=611) had MBC, of which 31.9% had bone only metastases, 39.6% visceral only, 18.0% had bone + visceral, and 10.5% had other metastasis sites. Most patients received either endocrine or chemotherapy (46.3% and 48.6%), while 3% were on both and 2.2% on neither therapy. Mean (SD) scores for FACT-G and FACT-B were 61.8 (15.8) and 85.9 (19.7) respectively. FACT scores stratified by current therapy and sites of metastases are in the table below. Significantly (p<0.05) better scores were reported in endocrine therapy patients compared to chemotherapy for all subscales. Significantly worse scores were reported in the bone + visceral group for all subscales except for SWB and FWB. Conclusions: Type of therapy and sites of metastases have a significant impact on patient reported BC QOL in HR+/HER2- ABC/MBC.

* P<0.05. Visceral = brain, liver, lung, pancreas.