KRAS Mutation Analysis (Test Code 220)
KRAS mutation status can predict response to anti-EGFR therapies
The presence of somatic mutations in the KRAS gene is associated with poor prognosis and non-response to anti-EGFR therapy in colorectal and non-small cell lung cancer patients. Studies evaluating KRAS mutation status in colorectal patients demonstrate that KRAS mutations are strongly correlated with lack of response to cetuximab and panitumumab, shorter progression-free survival (PFS) and shorter overall survival.1,2,3 Studies evaluating KRAS mutation status in NSCLC patients have shown that mutations in the KRAS gene are strongly predictive of resistance to tyrosine kinase inhibitors such as gefitinib and erlotinib.4,5,6
KRAS mutation testing is recommended by the National Comprehensive Cancer Network (NCCN) before starting EGFR-targeted therapy in both metastatic colorectal cancer and advanced non-small cell lung cancer patients.7,8 The American Society of Clinical Oncology (ASCO) favors routine KRAS mutation testing for patients diagnosed with metastatic colorectal cancer before initiating anti-EGFR therapies.
Specimen requirements
FFPE tumor tissue block containing ≥50% tumor or four (4) unstained 10 micron slides (plus 1 H&E).
We can also perform KRAS mutation analysis on specimens previously submitted to Exiqon Diagnostics/Oncotech for other oncology testing. Please call Client Services at 1-800-662-6832 to confirm that we have adequate specimen available on your patient to perform the test before sending in the requisition.
Ordering Information
The KRAS Mutation test is simple to order and can be performed on paraffin-embedded tumor tissue or slides. Simply fill out an Oncotech/Exiqon Diagnostics Requisition and request KRAS Mutation Analysis (Test Code 220). Test results will be available approximately 10 business days from time of specimen receipt.
Additional information on the KRAS Mutation Analysis, including an informational sheet and sample report, is available here:
Information Sheet (PDF download) and
Sample Report (PDF download) .
References: 1. Lievre et al. KRAS mutation status is predictive of response to cetuximab therapy in colorectal cancer. Cancer Res 66(8):3992-3995, 2006.
2. Karapetis et al. K-ras mutations and benefit from cetuxumab in advanced colorectal cancer. NEJM 359:1757-1765, 2008.
3. Amado et al. Wild-type KRAS is required for panitumumab efficacy in patients with metastatic colorectal cancer. J Clin Oncol 26 (10):1626-1634, 2008.
4. Massarelli et al. KRAS mutation is an important predictor of resistance to therapy with epidermal growth factor receptor tyrosine kinase inhibitors in non-small-cell lung cancer.Clin Cancer Res 13:2890-2896, 2007.
5. Pao et al. KRAS mutations and primary resistance of lung adenocarcinomas to gefinib or erlotinib, PLoS Med 2:e17, Epub2005
6. Eberhard et al. Mutations in the epidermal growth factor receptor and in KRAS are predictive and prognostic indicators in patients with NSCLC treated with chemotherapy alone and in combination with erlotinib. J Clin Oncol 23:5800-5909, 2005.
7. NCCN Clinical Practice Guidelines in Oncology™ Colon cancer. v 2.2009. Available at: http://www.nccn.org . Accessed March 20, 2009.
8. NCCN Clinical Practice Guidelines in Oncology™ Non-small cell lung cancer. v 2.2009. Available at: http://www.nccn.org . Accessed March 20, 2009.