Real-world outcomes of everolimus-based treatment in a Taiwanese cohort with metastatic HR+/HER2- breast cancer.

Background: Everolimus was the first orally targeted therapy for certain cancers. It was introduced before CDK4/6 inhibitors and is widely used to treat advanced hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. This study presents comprehensive findings including updated data and long-term survival analyses focusing on patients with HR+/HER2- metastatic breast cancer who received everolimus-based treatment. The objectives were to assess the impact of everolimus on overall survival (OS) and progression-free survival (PFS) by treatment line, and to evaluate its role in therapeutic strategies in a real-world setting.

Methods: We included 299 women aged over 20 years with histologically confirmed HR+/HER2- breast cancer who received everolimus-based treatment from multiple medical centers in Taiwan. Survival curves were generated using the Kaplan-Meier method, with the log-rank test for comparisons. Univariate and multivariate analyses were performed using a Cox proportional hazards regression model. Adverse effects were graded according to the Common Terminology Criteria for Adverse Events version 5.0.

Results: The median PFS was 5.6 months, and the median OS was 60.1 months. Patients receiving everolimus treatment in three or more lines and those who underwent chemotherapy prior to everolimus-based treatment had a significantly shorter PFS but longer OS. Patients with liver and central nervous system metastases had significantly shorter PFS and OS. The disease control rate was 51.5%, and the overall response rate was 8.0%.

Conclusion: These findings support current guidelines and advocate for the inclusion of everolimus in treatment plans for patients with metastatic HR+/HER2- breast cancer, particularly in late-line treatment, with careful consideration of the benefit-risk profile for each patient.