Background: Alterations in the human epidermal growth factor receptor-2 (HER2) pathway have been identified in a subset of salivary duct carcinomas. Dual HER2 inhibition with trastuzumab and pertuzumab has superior antitumor efficacy to trastuzumab monotherapy in HER2-positive breast cancer, yet its efficacy in HER2-positive salivary duct carcinoma is unknown.
Methods: We report 2 cases of exceptional responses of HER2-positive salivary duct carcinomas to dual HER2 blockade and docetaxel combination and their molecular characteristics.
Results: A 54-year-old man with recurrent metastatic HER2 expressing salivary duct carcinoma of the parotid gland after definitive concurrent chemoradiation achieved a complete response (CR) after 6 cycles of trastuzumab, pertuzumab, and docetaxel (TPH). A 42-year-old woman with HER2-positive salivary duct carcinoma of the parotid gland with bone and liver metastases had CR with TPH and remains in remission on maintenance trastuzumab and pertuzumab.
Conclusion: Dual HER2 blockage resulted in CR in patients with HER expressing salivary duct carcinoma and warrants further evaluation in this patient population.
Keywords: dual blockade; human epidermal growth factor receptor 2 (HER2); pertuzumab; salivary duct carcinoma; trastuzumab.
© 2018 Wiley Periodicals, Inc.