Patterns and outcomes in HR+/HER2- advanced/metastatic breast cancer patients in Brazil receiving palbociclib

<b>Aim:</b> To outline the demographic and clinical features, treatment approaches and clinical outcomes of patients treated with palbociclib as the initial therapy for HR+/HER2- advanced or metastatic breast cancer (aBC/mBC) in private healthcare facilities in Brazil.<b>Materials & methods:</b> This study involved a retrospective review conducted from June 2022 to May 2023.<b>Results:</b> The study included 121 patients, with an average age of 54.4 years, and 82 (67.7%) were menopausal at the time of diagnosis. Of these, 51 patients (42.1%) were treated with palbociclib and fulvestrant, while 67 patients (55.8%) received palbociclib and aromatase inhibitors. Most patients (65.3%) did not need to adjust their doses. The progression-free survival rates were 78% at 6 months and 60% at 12 months. Overall survival rates were 86% at 6 months and 70% at 12 months.<b>Conclusion:</b> Palbociclib combinations show promising effectiveness in managing HR+/HER2- advanced or metastatic breast cancer.