Detection of 19 mutations in KRAS codons 12, 13, 59, 61, 117 and 146
KRAS protein is a small GTPase and one of the key molecules in the downstream signaling pathway of epidermal growth factor receptor (EGFR). KRAS protein transduces signals from membrane-bound receptors via multiple downstream effector pathways and thereby affects fundamental cellular processes, including proliferation, apoptosis, and differentiation. KRAS mutations are particularly common in colon cancer, lung cancer, and pancreatic cancer. In total, activating mutations in the KRASgenes occur in 15~30% of lung cancer and 20~50% of colorectal cancer, mainly in exons 2, 3 or 4.
The KRAS gene mutation status of colorectal cancer patients is relevant to drug resistance of targeted medicines such as tyrosine kinase inhibitors. Patients with wild-type KRAS gene are much more likely to benefit from the Erbitux (Cetuximab) or Vectibix (Panitumumab), compared to patients with a mutant KRAS gene. The European Drug Administration Organization and US FDA recommend the employment of a KRAS gene mutation test prior to the usage of targeted medicine Erbitux and and Vectibix in the treatment of colorectal cancer.