In a patient with HR+HER2+ early breast cancer who is receiving adjuvant T-DM1 for residual disease, do you overlap endocrine therapy with T-DM1?

Yes, in the KATHERINE trial, endocrine therapy was started concurrent with the T-DM1, same with radiation as indicated. This is included I believe in the published supplement in KATHERINE. So...yes, both endocrine therapy and radiation are fine to start while on T-DM1.

Yes. In the KATHERINE trial, concomitant endocrine therapy was allowed per institutional standard, so I do overlap the ado-trastuzumab with the endocrine therapy chosen for the patient.