The BRAF gene encodes a protein that plays a key role downstream of KRAS in the cell signaling pathway from the Epidermal Growth Factor Receptor (EGFR) that activates important cell functions, including cell proliferation and survival.
As reviewed by Garnett and Marais in 2004, BRAF gene mutations are found in many different cancers, the highest incidence being found in malignant melanoma (27%–70%), papillary thyroid cancer (36%–53%), colorectal cancer (5%–22%) and serous ovarian cancer (30%). Many different mutations in BRAF have been identified, but most mutations are extremely rare. The V600E mutation predominates, being found in 86% of BRAF mutations in cancer.
BRAF mutations in colorectal cancer
The presence of the activating V600E BRAF mutation in a tumour indicates poor prognosis in colorectal cancer, and possibly also in other cancer types such as thyroid and lung cancers.
BRAF mutations in melanoma
A large proportion of melanomas have a mutated BRAF gene. This has led to the development of melanoma therapies that specifically inhibit the mutant BRAF.
The European Medicines Agency (EMA) and NICE have approved Vemurafenib (Zelboraf®) for the treatment of BRAF V600 mutation positive metastatic melanoma. The data from a Phase III trial (BRIM3) showed that at 6 months, overall survival for patients treated with Vemurefenib was 84%, with 63% reduction in risk of death compared to chemotherapy (Dacarbazine). Vemurafenib also increased the progression-free survival by 74% compared to chemotherapy.
Information for test processing
To request BRAF testing, the first point of contact is the dedicated Lab 21 Customer Services Team who handle:
- Test Requests and Customer Support
- Liaison with Sample Retention Sites for sample retrieval if required
- Reporting of the results
Lab 21 provides a BRAF mutation testing service from its accredited clinical laboratory using an accurate, CE-marked test method. Please provide sections of formalin-fixed, paraffin embedded (FFPE) tumour. Full requirements for sample preparation can be seen on the sample handling instructions.