Top Line:Tucatinib is increasingly used as part of combination systemic therapy for metastatic HER2+ breast cancer with impressive intracranial activity.
The Study: Unsurprisingly, the prospective studies establishing the efficacy of tucatinib provide little detail on how radiation was incorporated and resulting safety. Here is a retrospective look at 22 patients receiving brain radiosurgery for 139 (i.e., a whole lotta) brain mets while on tucatinib. Note some patients had more than one radiosurgery course. First of all, symptomatic radionecrosis occurred at only 6 treated lesions (4%). Local brain met control was excellent at 94% at one year and 81% at two years, but distant brain relapse was the rule with distant brain control rates of 39% at one year—we’re guessing at least in part because these patients had heavy-burden intracranial disease to start. Extracranial disease control was much better at 89% at one year, highlighting the continued importance of radiation in achieving intracranial disease control with tucatinib.
TBL: SRS appears to be relatively safe in the setting of tucatinib for HER2+ breast cancer brain metastases. | Khatri, J Neuro Oncol 2023
The Study: Unsurprisingly, the prospective studies establishing the efficacy of tucatinib provide little detail on how radiation was incorporated and resulting safety. Here is a retrospective look at 22 patients receiving brain radiosurgery for 139 (i.e., a whole lotta) brain mets while on tucatinib. Note some patients had more than one radiosurgery course. First of all, symptomatic radionecrosis occurred at only 6 treated lesions (4%). Local brain met control was excellent at 94% at one year and 81% at two years, but distant brain relapse was the rule with distant brain control rates of 39% at one year—we’re guessing at least in part because these patients had heavy-burden intracranial disease to start. Extracranial disease control was much better at 89% at one year, highlighting the continued importance of radiation in achieving intracranial disease control with tucatinib.
TBL: SRS appears to be relatively safe in the setting of tucatinib for HER2+ breast cancer brain metastases. | Khatri, J Neuro Oncol 2023