For patients with HER2+ breast cancer with a resectable HER2+ local relapse within 12 months of completion of standard adjuvant therapy including 1 year of trastuzumab, what adjuvant therapy would you recommend?

This is an interesting question as it implies likely primary resistance to trastuzumab. First, it depends upon the type of recurrence the patient experienced (ipsilateral, contralateral, chest wall recurrence post-mastectomy or axillary recurrence). Second it depends on the hormone receptor status of the primary and recurrent disease, and third it depends on adequacy of the local therapy for the primary. Finally, whenever this happens a restaging evaluation should occur.

Assuming there is no evidence of distant disease, a non-metastatic recurrence (i.e. chest wall recurrence, or a nodal recurrence) I would opt for either trastuzumab/pertuzumab x 1 year, or weekly paclitaxel x 12 weekly cycles and trastuzumab for x 1 year. Neratinib is also a...

I think an early local recurrence indicates persistent disease and per the results of the Katherine trial, patients with persistent disease after trastuzumab based chemotherapy have a much improved prognosis with TDM-1. I would offer at least 14 doses of this as in the Katherine trial, along with the appropriate hormonal therapy and radiation if needed