The proportion of treatment received during all lines of therapy in the metastatic setting will be described. The 2-year survival rate and median OS with interquartile range (IQR) for third-line therapy will be calculated. HRU data and costs during third-line therapy will be collected.
This retrospective observational study will collect Canadian real-world data (RWD) from HER2+ metastatic breast cancer (mBC) patients to describe treatment sequences of all therapies received in the metastatic setting, to measure overall survival (OS), progression free survival (PFS), time to next active anti-cancer therapy, and to estimate the health resources utilization (HRU) during third-line therapy.