Strategies to overcome resistance to epidermal growth factor receptor monoclonal antibody therapy in metastatic colorectal cancer

Figure 1 Epidermal growth factor receptor and its downstream signaling in colorectal cancer. Binding of ligands such as epidermal growth factor (EGF) to EGF receptor (EGFR) activates downstream Ras/ERK and PI3K/Akt pathways and regulates various physiological processes. EGFR administration of monoclonal antibodies (mAbs) (cetuximab and panitumumab) block activation of these pathways. Mutations of downstream molecules such as Ras, PI3K or Raf are associated with resistance to EGFR mAbs in patients with metastatic colorectal cancer (mCRC).