Real-world time trends in overall survival, treatments and patient characteristics in HR+/HER2- metastatic breast cancer: an observational study of the SONABRE Registry

Background This study aims to evaluate whether changes in therapeutic strategies have improved survival of patients diagnosed with hormone receptor positive (HR+), HER2 negative (HER2-) advanced breast cancer (ABC) in real-world. Methods All 1950 patients systemically treated for HR+/HER2- ABC and diagnosed between 2008 and 2019 in eight hospitals were retrieved from the SONABRE Registry (NCT-03577197). Patients were categorized per three-year cohorts based on year of ABC diagnosis. Tests for trend were used to examine differences in baseline characteristics, Kaplan-Meier methods and Cox proportional hazards for survival analyses, and competing-risk methods for 3-year use of systemic therapy. Findings Over time, patients were older (>= 70 years, 37%, n =169/456 in 2008-2010, 47%, n = 233/493 in 2017-2019, p = 0.004) and more often had multiple metastatic sites at ABC diagnosis (48%, n = 220/456 in 2008-2010, 56%, n = 275/493 in 2017-2019, p = 0.002). Among patients with metachronous metastases the prior exposure to (neo-) adjuvant therapies increased over time (chemotherapy, 38%, n = 138/362 in 2008-2010, 48%, n = 181/376 in 2017-2019, p = <0.001; endocrine therapy, 64%, n = 231/362 in 2008-2010, 72%, n = 271/376 in 2017-2019, p = <0.001). Overall survival significantly improved from median 31.1 months (95% CI:28.2-34.3) for patients diagnosed in 2008-2010 to 38.4 months (95% CI:34.0-41.1) in 2017-2019 (adjusted hazard ratio = 0.76, 95% CI:0.64-0.90; p = 0.001). Three-year use of CDK4/6 inhibitors increased from 0% for patients diagnosed in 2008-2010 to 54% for diagnosis in 2017-2019. Conversely, three-year use of chemotherapy was 50% versus 36%, respectively. Interpretation Over time, patients diagnosed with HR+/HER2- ABC presented with less favourable patient charac-teristics. Nevertheless, we observed that overall survival of ABC increased between 2008 and 2019, with increased use of endocrine/targeted therapies. Health -2023;26: Published 2023 https://doi.org/10. 1016/j.lanepe.2022. 100573