Clinicopathologic Features of Acute Kidney Injury Associated With CDK4/6 Inhibitors

Selective estrogen receptor inhibitors and aromatase inhibitors are the mainstay of therapy for HR+ breast cancer; however, most metastatic hormonal receptor-positive, HER2− breast cancers progress and acquire resistance to endocrine therapies.1 CDK4/6 inhibitors comprise a new class of drugs that overcome this resistance by blocking the transition from the G1 to the S phase of the cell cycle, thereby preventing cell-cycle progression and cancer growth.2 There were 3 CDK4/6 inhibitors—palbociclib, ribociclib, and abemaciclib—that have been approved for HER2− metastatic breast cancers, usually in combination with hormone therapy.