How would you manage new symptomatic brain metastases (10-15) in a young woman with HER2+ metastatic breast cancer?

A lot of nuance to answering this on a per-patient basis.

First question, how symptomatic? (As in, are there bulky mets that we should be considering surgical management upfront plus this also guides my discussion about whole brain vs systemic)

If not acutely symptomatic and requiring a crani/resectio...

In a young woman with HER2+ metastatic breast cancer and new symptomatic brain metastases (10-15 lesions not candidate for SRS), with controlled extracranial disease on trastuzumab and pertuzumab, the treatment strategy should prioritize CNS control quickly. If she is truly symptomatic and symptoms ...

I would certainly change systemic therapy to tucatinib or T-Dxd because it’s clear that disease progression is happening, and it is in CNS in this case. It is not yet clear that systemic disease is independent of CNS disease. Depending on symptoms and localization of lesions in the brain, if immedia...