KRAS and BRAF Mutation Testing for Colorectal Tumors

Now Available at PhenoPath Laboratories

Testing for the presence of mutations in the KRAS gene, a finding present in 30-40% of colorectal adenocarcinomas, and BRAF, present in ~10% of colorectal adenocarcinomas, has become a critical and essential test to determine which patients will benefit from the addition of cetuximab (Erbitux™) therapy.

Both KRAS and BRAF are key components of the EGFR signal transduction pathway. When KRAS and BRAF are mutated, they are constitutively activated, and tumors carrying these activating mutations have been shown to be resistant to anti-EGFR therapy. In controlled clinical trials, patients with colorectal tumors having mutated KRAS or BRAF were resistant to anti-EGFR antibody therapy and had similar progression-free survival (PFS) and overall survival (OS) compared to untreated control patients. In contrast, patients with wild type KRAS and BRAF did benefit from anti-EGFR therapy with improved PFS and OS compared to controls. Therefore, KRAS and BRAF mutation status is a key predictor of patient responsiveness to anti-EGFR antibody therapy.

FAQs

What kind of specimen do I need to submit to PhenoPath Laboratories to permit KRAS and/or BRAF mutational analysis?
Paraffin blocks of formalin-fixed tissue, or cut sections from blocks, are most appropriate. Please contact PhenoPath Laboratories for recommendations regarding cut sections or the handling of scant or fresh specimens, including FNAs. Our staff will work with you to ensure proper handling of any type of specimen. We also have experience with DNA extractions performed on specimens fixed in non-formalin-based fixatives.
Colorectal adenocarcinoma

What is the turnaround time for KRAS and/or BRAF mutational analysis?
Turnaround time is usually 4-6 days or less from receipt of specimen.

How has PhenoPath Laboratories validated this assay?
The KRAS and BRAF mutational assays have been rigorously validated by direct DNA sequence verification on control cell lines as well as on a large number of colorectal cancer specimens to ensure accurate results. Our assay can detect KRAS or BRAF mutations when cells containing the mutation comprise ≤ 1% of the specimen, which is an industry standard for this assay. Additionally, the assay has been cross validated with other methodologies.

If you or your clinicians have any questions regarding PhenoPath Laboratories' KRAS mutational assay, contact us at 206-374-9000, or by email at lab@phenopath.com.