Anti-EGFR Therapy for Metastatic Colorectal Cancer in the Era of Extended RAS Gene Mutational Analysis.

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. In the past 2 decades, advances in cancer therapeutics allowed for a remarkable improvement in terms of survival for patients with metastatic CRC. The advent of targeted therapy, coupled with more efficient chemotherapy regimens, was the pillar achievement that contributed to the success of CRC therapy. Cetuximab and panitumumab, monoclonal antibodies targeting the epidermal growth factor receptor pathway, are the focus of this review since their mechanism of action and efficiency are closely related to the mutational status of a predictive biomarker, the Kristen rat Sarcoma viral oncogene (KRAS). More recently, another biomarker, the neuroblastoma rat sarcoma viral oncogene (NRAS), was found to be as valuable for the refinement of this targeted therapy. The arguments for the use of extended analysis of the RAS gene are thoroughly reviewed because they directly affect the choice of targeted agents and potentially the choice of backbone chemotherapy.