Endocrine Maintenance Therapy in High-Grade Serous Ovarian Cancer: A Retrospective Off-Label Real-World Cohort Study

Area of Science:

• Gynecologic Oncology
• Medical Oncology
• Endocrinology

Background:

• Estrogen receptor (ER)-positive breast cancers and low-grade serous ovarian cancer typically benefit from endocrine therapy.
• The role of endocrine therapy as maintenance treatment in early-stage, ER-positive high-grade serous ovarian cancer (HGSC) is not well-defined.

Purpose of the Study:

• To evaluate the efficacy and safety of letrozole as maintenance therapy in patients with newly diagnosed ER-positive HGSC.
• To determine if letrozole improves progression-free survival (PFS) and overall survival (OS) in this patient population.

Main Methods:

• A retrospective analysis of 102 patients with newly diagnosed ER-positive HGSC was performed.
• Patients received maintenance therapy with or without letrozole post-chemotherapy.
• Outcomes were analyzed, stratifying by residual disease status.

Main Results:

• Maintenance letrozole was well-tolerated with no major adverse effects.
• Overall, letrozole did not significantly improve PFS or OS in the entire cohort.
• However, in patients with no residual disease, letrozole significantly improved OS (median 114 months vs. 46.9 months, p=0.006).

Conclusions:

• Maintenance letrozole is a safe option for ER-positive HGSC patients.
• It shows potential benefit, particularly for improving overall survival in patients with no residual disease.
• Further prospective trials are needed to confirm these findings and assess quality of life implications.