Posterior Reversible Encephalopathy Occurring During Treatment With Palbociclib

Area of Science:

• Neuro-oncology
• Pharmacology
• Radiology

Background:

• Palbociclib (Ibrance™) is a targeted therapy approved for metastatic hormone-receptor-positive breast cancer.
• Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors represent a significant advancement in breast cancer treatment.

Observation:

• A 67-year-old woman on palbociclib presented with headaches and seizures.
• Brain MRI revealed bilateral, symmetrical subcortical white matter abnormalities consistent with PRES.
• Neurological symptoms resolved after palbociclib discontinuation.

Findings:

• The patient's presentation and MRI findings were consistent with posterior reversible encephalopathy syndrome (PRES).
• Discontinuation of palbociclib led to complete neurological recovery.
• Follow-up MRI showed a decrease in white matter signal abnormalities.

Implications:

• Physicians should consider PRES in patients treated with CDK4/6 inhibitors, especially those with risk factors like hypertension or autoimmune disease.
• Early recognition and discontinuation of palbociclib may prevent severe neurological sequelae.
• This case underscores the importance of vigilant monitoring for PRES during CDK4/6 inhibitor therapy.