|
ONCOLOGY REQUISITION
For specimen requirements, TAT and CPT codes click on the test code.
Colorectal cancer is a major cause of cancer mortality. The KRAS mutation assay was designed to assist clinicians in selecting therapy for patients with advanced colorectal cancer. Treatment with a monoclonal antibody directed against the epidermal growth factor receptor (EGFR) improves overall survival in patients with advanced colorectal cancer refractory to standard chemotherapeutic regimens. However, this survival benefit from EGFR-inhibitor therapy is only present in patients with wild-type KRAS, while patients with mutated KRAS show no survival benefit. Mutations in codons 12 and 13 of exon 2 of KRAS are present in approximately one third of colonic adenocarcinomas. Thus, the identification of KRAS mutations in patients with advanced colorectal cancer represents a clinically useful tool for selecting patients for treatment with EGFR inhibitors.
The KRAS mutation detection assay includes DNA extraction from Paraffin-embedded tissues, DNA purification, amplification of a region of KRAS exon 2, and detection of codon 12 and 13 mutations using the TrimGen KRAS Mutector Mutation Detection Assay. In cases with equivocal results using the TrimGen Mutector, direct DNA sequencing of KRAS exon 2 will be performed with primers that cover codons 12 and 13 in both the forward and reverse direction.
Complete listing of laboratory departments and available test directory here.
Back to Top |
