The cobas KRAS mutation test developped by Roche Molecular Systems , a polymerase chain reaction-based diagnostic tool intended for the detection of mutations in codons 12, 13 and 61 of the KRAS gene, is now commercially available in Europe and other countries that recognize the CE mark. The system tests colorectal cancer tissue predictive of individual response to therapy with anti-epidermal growth factor receptor (EGFR) antibody therapies.
“By quickly and reliably detecting KRAS mutations, the cobas KRAS Mutation Test provides oncology professionals with a new, validated tool to help guide and personalize treatment of colorectal cancer,” said Paul Brown, head of Roche Molecular Systems (RMS), the business area of Roche that developed the test.
High sensitivity
KRAS mutations occur in 35 to 45 percent of colorectal cancers. The remaining tumors (approximately 60 percent) have no KRAS mutations, and are referred to as KRAS wild type. The cobas KRAS Mutation Test was designed to detect KRAS mutations with high sensitivity, which is important because of the safety issues of treating mutation positive patients with anti-EGFR monoclonal antibody therapies. The test detects mutations in codons 12, 13 and 61 of the KRAS gene.
EGFR-targeted monoclonal antibodies
There is strong evidence that tumor KRAS status is a predictive biomarker of efficacy for EGFR-targeted monoclonal antibodies. Treatment with EGFR-targeted monoclonal antibodies is beneficial in patients with KRAS wild-type colorectal cancer, whereas it is not effective, or may even be detrimental, in patients with KRAS mutations.
KRAS mutation testing
International oncology organizations such as the American Society of Clinical Oncology (ASCO),[1] the National Comprehensive Cancer Network (NCCN)[2] and the European Society for Medical Oncology (ESMO) recommend KRAS mutation testing for the selection of patients to receive anti-EGFR antibody therapy.[3] United States and European regulatory authorities have restricted the use of these agents to patients with KRAS wild-type tumors.
For more information:
[1] Allegra CJ, Jessup JM, Somerfield MR, et al. American Society of Clinical Oncology provisional clinical opinion: testing for KRAS gene mutations in patients with metastatic colorectal carcinoma to predict response to anti-epidermal growth factor receptor monoclonal antibody therapy. J Clin Oncol 2009 Apr 20;27(12):2091-6.
[2] National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Colon cancer, 2010, v.2.
[3] Van Cutsem E, Oliveira J; ESMO Guidelines Working Group. Advanced colorectal cancer: ESMO clinical recommendations for diagnosis, treatment and follow-up. Ann Oncol 2009 May;20 Suppl 4:61-3.
