How do you approach the treatment of de novo, brain-only metastatic HER2 positive breast cancer?

Patients who present with de novo, brain-only metastases of HER2+ breast cancer are rare, and hence, there is no good clinical experience or clinical trial basis upon which to base clinical practice recommendations. The current ASCO guidelines for the management of HER2+ brain metastases call for ap...

In cases of brain-only recurrence in metastatic HER2+ breast cancer, the treatment approach should focus on achieving CNS control with local therapy and then shifting to a CNS secondary prevention strategy with systemic therapy. After local therapy to the brain, systemic therapy does improve overall...

I think these patients should be evaluated for localized CNS therapy, especially if they are symptomatic. After completion of CNS-directed therapy, I would either proceed with standard-of-care first-line systemic therapy THP or consider the use of T-DXd if able to obtain insurance approval.