ABSTRACT
Biomedicai advances in molecular understanding of colorectal cancer (CRC) have led to the identification of many genetic alterations as potential therapeutic targets. Research has advanced understanding of the molecular substructure of CRC and directed the development of new therapeutic strategies against actionable targets. For many of these new targeted therapies, clinicians must first identify which individuals will derive benefits. The KRAS proto-oncogene encodes a guanosine triphosphate/guanosine diphosphate binding protein that acts downstream of EGFR in the RAS/RAF/MAPK pathway. Approximately 40% of CRCs exhibit mutations in codons 12 or 13 in exon 2 of the coding region of the KRAS gene and these mutations are widely accepted as predictive biomarkers for the response to treatment with anti-EGFR drugs in patients with metastatic CRC. The lifetime risk for CRC is approximately 5% in developed countries. Molecular biomarkers play an increasingly important role in informing decisions about targeted therapies.
