From Research to Policy Implementation: Trastuzumab in Early-Stage Breast Cancer Treatment in Thailand.

•A number of patients with early-stage breast cancer have overexpression of human epidermal growth factor receptor 2, which has been correlated with metastatic breast cancer and death.•Trastuzumab is a monoclonal antibody, which specifically targets tumor cells that overexpress human epidermal growth factor receptor 2 proteins and can prolong patient survival time.•Economic evaluation of adjuvant therapy with trastuzumab and paclitaxel for the treatment of early-stage breast cancer was conducted in Thailand.•The results revealed that adjuvant trastuzumab was cost-effective with an incremental cost-effectiveness ratio of THB 118 572 (THB = Thai baht) per quality-adjusted life-year gained.•In 2014, trastuzumab was approved to be included in the National List of Essential Medicines.