title: EGFR and KRAS in colorectal cancer.
abstract: The epidermal growth factor receptor (EGFR) is recognized as an important player in colorectal cancer (CRC) initiation and progression. This membrane-bound receptor tyrosine kinase (RTK) has therefore become a key target of therapeutic strategies designed to treat metastatic CRC, in particular with monoclonal antibodies (mAbs) against the extracellular domain of the receptor. KRAS is an effector molecule responsible for signal transduction from ligand-bound EGFR to the nucleus. Activating mutations in KRAS are recognized as a strong predictor of resistance to EGFR-targeted mAbs. Routine testing of all patients with CRC for KRAS mutations is now recommended; only those harboring wild-type (WT) KRAS should be candidates for such therapies, thus improving outcomes, and minimizing unnecessary toxicity and cost. Even though the identification of the importance of KRAS status has marked a turning point in the treatment of metastatic CRC (mCRC), it is becoming apparent that other critical elements in the complex signaling pathways related to EGFR may also contribute vital information that will aid in treatment decisions and ultimately benefit patients.
authors.affiliation: Medical Oncology Department, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron University Hospital, Barcelona, Spain.
authors.forename: Ben
authors.initials: B
authors.lastname: Markman
authors.forename: Francisco
authors.initials: F
authors.lastname: Javier Ramos
authors.forename: Jaume
authors.initials: J
authors.lastname: Capdevila
authors.forename: Josep
authors.initials: J
authors.lastname: Tabernero
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D002986:Clinical Trials as Topic; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000502:physiology*; D006801:Humans; D009154:Mutation; D051059:PTEN Phosphohydrolase / Q000502:physiology; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D012084:Renin-Angiotensin System / Q000502:physiology; D015398:Signal Transduction; D018631:ras Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins