Efficacy and safety of Trastuzumab added to standard treatments for HER2-positive metastatic breast cancer patients.

Trastuzumab, an HER2-targeting agents, has shown efficacy in metastatic HER2-positive breast cancer patients. Single-agent clinical trials have evaluated therapeutic regimens using trastuzumab for metastatic breast cancer patients. The aim of our study is to evaluate the efficacy and safety of trastuzumab in combination with chemotherapy or hormone therapy in HER2-positive metastatic breast cancer patients.