Survival outcomes for Australian women receiving trastuzumab for HER2-positive metastatic breast cancer following (neo)adjuvant trastuzumab: a national population-based observational study (2006–2014).

Patients treated with (neo)adjuvant trastuzumab who relapse and receive trastuzumab for metastatic breast cancer (MBC) are a growing population with little outcome data given their exclusion from most clinical trials. We aim to estimate survival outcomes for this trastuzumab ‘pre-treated’ population. Population-based study of Australian women receiving trastuzumab for HER2-positive MBC between 2006 and 2014, who also received (neo)adjuvant trastuzumab. We used Kaplan–Meier methods to estimate the following: overall survival (OS) from initiation of trastuzumab for MBC; duration of trastuzumab for MBC; and time from last (neo)adjuvant trastuzumab to first trastuzumab for MBC