Role of ado-trastuzumab emtansine (T-DM1) in HER2 positive salivary gland tumour with brain metastasis

Abstract

Malignant neoplasms of salivary gland neoplasms are rare and often involve the parotid gland. The primary treatment of these malignancies is surgery with or without adjuvant therapy. Chemotherapy or systemic therapy is indicated in recurrent or metastatic disease where surgery or radiotherapy is not possible. Salivary gland carcinomas, which are human epidermal growth factor receptor 2 (HER2) positive, show an aggressive behaviour with a poor prognosis. Targeting the HER2 pathway with drugs designed to block this pathway is an interesting novel therapy to treat salivary gland carcinomas. We report a case of a patient with HER 2-overexpressing parotid gland adenocarcinoma with brain metastasis, who was managed with ado-trastuzumab emtansine (T-DM1): a monoclonal antibody-cytotoxic drug conjugate that combines trastuzumab with the microtubule inhibitor, emtansine. The patient showed excellent response to the therapy. This case highlights the role of systemic chemotherapy with T-DM1 in HER2 positive salivary gland tumours that could be considered a part of the treatment regimen.