FOLFOX + FOLFIRI + CAPEOX + cetuximab + bevacizumab

This is a combination regimen consisting of three standard chemotherapy protocols—FOLFOX, FOLFIRI, and CAPEOX—together with two targeted monoclonal antibodies, cetuximab and bevacizumab. These regimens are primarily used in the treatment of advanced or metastatic colorectal cancer. - **FOLFOX** combines folinic acid (leucovorin), fluorouracil (5-FU), and oxaliplatin. Folinic acid enhances the effect of 5-FU, which inhibits thymidylate synthase to disrupt DNA synthesis in rapidly dividing cells; oxaliplatin forms DNA cross-links leading to cell death[2][5]. - **FOLFIRI** includes folinic acid (leucovorin), fluorouracil (5-FU), and irinotecan. Irinotecan inhibits topoisomerase I, preventing DNA replication[2][3]. - **CAPEOX** (also known as XELOX) consists of capecitabine (a prodrug converted to 5-FU) and oxaliplatin[1][2]. Capecitabine interferes with DNA synthesis after conversion to 5-FU; oxaliplatin acts as above. - **Cetuximab** is a monoclonal antibody targeting the epidermal growth factor receptor (EGFR), blocking downstream signaling pathways involved in tumor growth. - **Bevacizumab** is a monoclonal antibody that binds vascular endothelial growth factor A (VEGF-A), inhibiting angiogenesis required for tumor blood supply.