RecruitingPhase 2Drug trialPost-op T-DM1 in HER-2+ Salivary Gland CarcinomasThis research is being done to see how safe and effective the use of the study drug Ado-trastuzumab (T) emtansine (DM1), T-DM1, and standard of care chemoradiation are when used together in treating HER2-positive salivary gland cancer. It will also examine the effectiveness of study drug Ado-trastuzumab (T) emtansine (DM1) on cancer recurrence.