Comparative Efficacy of Second-line Anti-VEGF Continuation and Anti-EGFR Switch Strategies in RAS Wild-type Metastatic Colorectal Cancer Patients Progressing on First-line Anti-VEGF Therapy: A Retrospective Single-center Study

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ÇOKGEZER S., SAĞLAM E. N., Bayrak İ. S., Şenkal M., BOZBEY H. U., TAŞTEKİN D., ...More

Journal of Oncological Science, vol.12, no.2, pp.269-281, 2026 (Scopus, TRDizin)

Abstract

Objective: The optimal selection of second-line biological therapy remains unclear in patients with RAS wild-type metastatic colorectal cancer (mCRC) who develop disease progression following first-line anti-vascular endothelial growth factor (VEGF)-based treatment. This study aimed to compare the efficacy and safety outcomes of continuation of second-line anti-VEGF therapy versus switching to anti-epidermal growth factor receptor (EGFR) therapy. Material and Methods: This retrospective single-center study included 38 patients with RAS wild-type mCRC who were treated between January 2015 and December 2025. All patients received bevacizumab-based chemotherapy in the first-line setting and subsequently developed disease progression. Patients were divided into two groups according to the second-line biological therapy administered concomitantly with chemotherapy: anti-VEGF continuation (n=20) and anti-EGFR switch (cetuximab/panitumumab; n=18). The primary endpoints were second-line progression-free survival (PFS2) and overall survival (OS). Results: Median PFS2 was 7.1 months in the anti-VEGF group and 10.0 months in the anti-EGFR group (p=0.404). Median OS were 28.2 months and 25.5 months, respectively (p=0.752). No significant differences were observed between the groups in survival outcomes. Left-sided colon tumors were more frequent in the anti-EGFR group, whereas right-sided colon tumors were more frequent in the anti-VEGF group. Skin rash was significantly more common with anti-EGFR therapy (22.2%; p=0.041), while other toxicities were manageable. Conclusion: In patients with RAS wild-type mCRC progressing after first-line anti-VEGF therapy, second-line anti-VEGF continuation and anti-EGFR switch strategies demonstrated comparable survival outcomes. Treatment selection should be individualized based on tumor sidedness, prior treatment response, toxicity profile, and patient characteristics.