Clinical Report: Inhibitors of Cyclin-Dependent Kinase 4/6 in Granulosa Cell Tumors
Overview
This scoping review evaluates the potential of CDK4/6 inhibitors in treating adult granulosa cell tumors (aGCT) alongside hormonal therapies. Clinical data remain limited.
Background
Adult granulosa cell tumors (aGCT) are rare ovarian malignancies characterized by late recurrences and limited treatment options. The dysregulation of the cyclin D–CDK4/6–Rb axis has been implicated in aGCT biology, indicating a potential therapeutic target. The expression of hormone receptors in these tumors further supports the exploration of endocrine therapy in conjunction with CDK4/6 inhibitors.
Data Highlights
No numerical or trial data presented in the source material.
Key Findings
Twenty-three reports were included in the review, highlighting the dysregulation of cell-cycle regulation in aGCT.
Preclinical studies indicated that CDK4/6 inhibition, particularly with abemaciclib, reduced cell viability and tumor growth in GCT models.
Clinical evidence is limited to small retrospective case series suggesting disease control in some patients with recurrent aGCT.
Ongoing phase II trials aim to systematically evaluate the efficacy of CDK4/6 inhibitors in aGCT.
Combination strategies of CDK4/6 inhibitors with endocrine therapy appear promising based on preliminary findings.
Clinical Implications
Further prospective studies are needed to validate the strategies involving CDK4/6 inhibitors and hormonal treatments.
Conclusion
Further investigation is warranted due to the current limitations in clinical data.
Harold Burstein, MD, PhD, and Erica Mayer, MD, MPH discuss results from the TRAK-ER trial, which were presented at the 2026 ESMO Breast Cancer Congress.
