BRAF Mutation Analysis (Test Code 221)

BRAF mutation status can predict response to anti-EGFR therapies

The presence of the V600E mutation in the BRAF gene is associated with poor prognosis and nonresponse to anti-EGFR therapy in advanced stage colorectal cancer patients. Studies show that colorectal cancer patients with wild-type KRAS failed to respond when treated with either cetuximab or panitumumab and experienced a shorter progression-free survival and overall survival, when the BRAF mutation was present, compared to patients with wild-type BRAF tumors.1

KRAS mutations are found in approximately 30 percent of colorectal cancer patients who fail to respond to standard anti-EGFR therapy.2-5 An additional 15 percent of patients may also be nonresponsive due to a mutation of the BRAF gene.1 Screening for both BRAF and KRAS mutation status in advanced stage colorectal cancer can provide important information to the clinician regarding potential candidates for cetuximab or panitumumab. Exiqon Diagnostics offers both BRAF and KRAS mutation analysis for colorectal cancer patients.

Specimen requirements

FFPE tumor tissue block containing ≥50 percent tumor or four (4) unstained 10 micron slides (plus 1 H&E).

We can also perform BRAF 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 BRAF 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 (PDF download) and request BRAF Mutation Analysis (Test Code 221). Test results will be available approximately 10 business days from time of specimen receipt.

Additional information on the BRAF Mutation Analysis, including an informational sheet and sample report, is available here:

• BRAF Information Sheet 
• BRAF Sample Report

References:
1. Di Nicolantonio et al. Wild-type BRAF is required for response to panitumumab or cetuximab in metastatic colorectal cancer. J Clin Oncol 26:5705-12, 2008. 2. Benvenuti et al. Oncogenic activation of the RAS/RAF signaling pathway impairs the response of metastatic colorectal cancers to anti-epidermal growth factor receptor antibody therapy. Cancer Res 67:2643-2648, 2007.
3. Lievre et al. KRAS mutation status is predictive of response to cetuximab therapy in colorectal cancer. Cancer Res 66(8):3992-3995, 2006.
4. Karapetis et al. K-ras mutations and benefit from cetuxumab in advanced colorectal cancer. NEJM 359:1757-1765, 2008.
5. 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.