Efficacy of First-line Therapy With Anti-EGFR Versus Anti-VEGF Therapy for WT RAS Metastatic Colorectal Cancer: Real-world Experience from a Single Institute

Abstract Background/Aim: Top prospective clinical trials comparing anti-epidermal growth factor receptor (EGFR) therapy and anti-vascular endothelial growth factor (VEGF) therapy plus chemotherapy for wild-type Ras proto-oncogene, GTPase (WT RAS) metastatic colorectal cancer (mCRC) have yielded different outcomes, and real-world data are lacking. This study established real-world experiences and identified challenges in treating patients with mCRC. Patients and Methods: This retrospective study identified first-line regimens for patients with mCRC on anti-EGFR or anti-VEGF therapy plus chemotherapy. The effects on overall survival (OS) were estimated; secondary endpoints were progression-free survival (PFS). OS in the two groups was compared on the basis of sex, age, primary tumor site, oxaliplatin-based chemotherapy, and number of organs with metastases through Cox multivariate regression analysis. Results: A total of 129 patients diagnosed with WT RAS mCRC from June 1, 2018, to December 31, 2021, were included. The median OS was 33.3 months for the anti-EGFR group (n = 78) and 26.1 months for the anti-VEGF group (n = 51; 95% confidence interval = 1.008–2.550; p = 0.044). PFS was 17.6 and 12 months, respectively (95% confidence interval = 0.9-1.963; p = 0.15). Multivariate Cox regression models revealed good OS for patients with WT RAS and left-sided primary tumor. The liver-only metastasis conversion rate after systemic chemotherapy was higher in the anti-EGFR group. Conclusion: High survival rates can be achieved when anti-EGFR is used in patients with WT RAS mCRC. Surgery still plays an important role in patients with mCRC and on systemic treatments.