Efficacy of cetuximab/panitumumab after previous bevacizumab in metastatic colorectal cancer

Abstract

The optimal sequence of the targeted therapies in metastatic colorectal cancer is not established. We aimed to analyse if previous administration of bevacizumab impacts the response to epidermal growth factor receptor inhibitors in subsequent lines of therapy. It was performed a retrospective analysis on KRAS or KRAS/NRAS wild-type metastatic colorectal cancer patients that received an epidermal growth factor receptor inhibitor in the second or later lines of therapy and their outcomes were analysed according to previous exposure to bevacizumab. 85 metastatic colorectal cancer patients were included, of whom 22 had received previous chemotherapy (group A) and 63 previous chemotherapy plus bevacizumab (group B). The overall survival was significantly higher in the group B (35.6 months versus 24.8 months, p = 0.01). The overall survival and progression-free survival calculated from the start of the epidermal growth factor receptor inhibitor did not significantly differ between the groups. The multivariate analysis revealed that using bevacizumab did not significantly impact the survival. Our results show that previous administration of bevacizumab does not influence the efficacy of epidermal growth factor receptor inhibitors in later lines of treatment.