How do you select systemic therapy for recurrent HR+ HER2 negative breast cancer in the bones in a premenopausal woman within a year of starting adjuvant AI with OFS plus abemaciclib and zoledronic acid?

This is, unfortunately, a case of primary endocrine resistance, and recurrence on adjuvant Abemaciclib makes the case more challenging for this pre-menopausal patient.

It would be reasonable to repeat tissue biopsy to rule out a change in hormone receptor status and consider blood based ctDNA analysi...