Survival, treatment patterns, and costs of HER2+ metastatic breast cancer patients in Ontario between 2005 to 2020.

The baseline characteristics and treatment patterns for patients who received HER2-TT in our study align with previously reported results. However, the mOS observed for 2L T-DM1 was shorter than that found in pivotal, clinical trial literature. As expected, anti-cancer systemic therapy costs were the main contributor to the over quarter-million dollar mean cost per patient on pert_tras in 1L.