How would you approach systemic therapy for a postmenopausal female with metastatic ER+/HER2+ breast cancer (liver/bone) who achieved a CR for 5 years on trastuzumab/pertuzumab and exemestane, with continued asymptomatic brain progression?

Switch to tucatanib, capecitabine, and trastuzumab. Consider returning to trastuzumab/pertuzumab based treatment at future systemic progression since currently there's no systemic progression.

Consider continuing exemestane. This could be based on recent NSABP trials showing no detriment to concomit...