HR+ Metastatic Breast Cancer Treatment Sea Change

Joyce O’Shaughnessy, MD:The main clinical point for this patient is that historically, pretty much all of us would have recommended chemotherapy at presentation with a rapidly enlarging breast mass, axillary adenopathy, and multiple liver metastasis. I think chemotherapy would have been the go-to therapy. We probably would not have utilized single-agent endocrine therapy because of the tempo of the disease. And I think the sea change in clinical practice is the consideration of CDK4/6 [cyclin-dependent kinases 4 and 6] inhibitors for this patient.

The data suggest that they’re equal to chemotherapy, with CDK4/6 inhibitors plus endocrine therapy, equal to chemotherapy in response rates, clinical benefit rates, tempo of response, but much longer progression-free survival, and of course much less toxicity. So an overall win for the patients. And I think that my practice pattern has slowly evolved over the last couple of years, and I would be comfortable with abemaciclib for this patient because of the subset analysis, specifically in the subsets of patients with her concerning clinical characteristics—progesterone receptor-negative, liver metastasis, grade 3 disease. So that would be my choice for this patient. And hopefully we’ll see some head-to-head comparisons over time specifically for this patient.

Transcript edited for clarity.

Case: A 62-Year-Old Woman WithDe NovoInvasive Ductal Carcinoma

• A 62-year-old woman presented to her gynecologist with a large mass in her right breast
• Breast MRI confirmed the presence of a 6-cm mass and axillary adenopathy
• Labs: ALT 95, AST 70 (elevated)
• Core needle biopsy confirmed ER+ PR (-) HER2(-) carcinoma, grade 3
• CT chest, abdomen, and pelvis showed widely scattered liver metastases