Comparison of Third-Line Treatment Options in Patients with Metastatic Renal Cell Carcinoma

Aim: Metastatic renal cell carcinoma (mRCC) is a challenging malignancy requiring multiple lines of therapy. While tyrosine kinase inhibitors remain the standard first-line treatment, resistance often necessitates further therapeutic options. Nivolumab, everolimus, axitinib, and cabozantinib are commonly used in later-line settings, but the optimal sequencing strategy remains unclear. Methods: This retrospective study analyzed 32 patients with mRCC treated at University of Health Sciences Türkiye, Gülhane Training and Research Hospital between January 2015 and December 2022. All patients had received at least two prior systemic therapies. Survival outcomes were assessed using Kaplan-Meier analysis. Progression-free survival (PFS) and overall survival (OS) were compared among treatment groups using the Log-Rank test. Results: Axitinib was the most frequently used third-line therapy (50.0%), followed by everolimus (25.0%), cabozantinib (12.5%), and nivolumab (12.5%). Nivolumab showed the longest median PFS (41.0 months, p=0.034) and OS (149.0 months), although OS differences were not statistically significant (p=0.154). Conclusion: This study highlights variation in third-line treatment patterns and outcomes among mRCC patients. Nivolumab and axitinib demonstrated promising efficacy, suggesting their consideration as preferred options in this setting.