Corneal Epithelial Alterations Associated With Cyclin-Dependent Kinase 4/6 Inhibitor Therapy in Hormone...

Area of Science:

• Ophthalmology
• Oncology
• Cell Biology

Background:

• Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are a standard treatment for hormone receptor-positive (HR+), HER2-negative breast cancer.
• These inhibitors target the G1/S cell-cycle transition, potentially affecting rapidly proliferating tissues like the corneal epithelium.
• There is a lack of controlled studies on corneal changes in patients undergoing CDK4/6 inhibitor therapy.

Purpose of the Study:

• To investigate the association between CDK4/6 inhibitor therapy and corneal epithelial alterations.
• To determine if these corneal changes are independent of aromatase inhibitor (AI) use and tear film dysfunction.

Main Methods:

• A retrospective, comparative cross-sectional study involving 132 women.
• Participants were categorized into three groups: CDK4/6 inhibitor plus AI (CDKAI), AI monotherapy (AI), and age-matched controls.
• Corneal changes (punctate epitheliopathy, vortex keratopathy) and tear film parameters (Schirmer I test, TBUT, OSDI) were assessed.

Main Results:

• Punctate epitheliopathy (PE) was significantly more prevalent in the CDKAI group (44.4%) compared to the AI group (4.7%) and controls (2.3%).
• All moderate and severe PE cases, along with vortex keratopathy (13.3%), were observed exclusively in the CDKAI group.
• No significant differences in tear film parameters (Schirmer, TBUT, OSDI) were found among the groups.

Conclusions:

• CDK4/6 inhibitor-based therapy is associated with a higher incidence and severity of punctate epitheliopathy and vortex keratopathy.
• These corneal effects appear independent of AI exposure and dry eye conditions, suggesting a direct impact on the corneal epithelium.
• Routine corneal evaluation using fluorescein staining may be beneficial for patients on CDK4/6 inhibitors.