INTRODUCTION
tumor, breast cancer, breast and gastric cancers),In, breast tumor, colorectal, and bladder cancers
TUMOR, BREAST CANCER, DISEASE, SOLID TUMORS, BREAST TUMOR, METASTATIC BREAST CANCER
Gene amplification or overexpression of the protein encoded by the erb‐B2 receptor tyrosine kinase 2 (By IHC, a breast tumor is considered HER2‐positive if scored as IHC 3+ based on circumferential membrane staining that is complete, intense, and in >10% of tumor cells. By ISH, a breast tumor is considered HER2‐positive if the ratio of HER2 testing guidelines exist only for tumor types with approved HER2‐targeted therapies (i.e., breast and gastric cancers),In the United States and the European Union, T‐DM1 is approved for use in patients with previously treated HER2‐positive metastatic breast cancer and in patients with HER2‐positive early breast cancer who have residual invasive disease following neoadjuvant treatment. Previous clinical trials have demonstrated the efficacy of HER2‐targeted therapies in non‐breast solid tumors, including biliary tract, non‐small cell lung, colorectal, and bladder cancers,