Melanoma and colorectal cancer: BRAF screen
Also known as: BRAF gene test
Test category:
Oncology - Melanoma
Use of test
Purpose:
Certain mutations in the BRAF gene in some solid tumours are associated with responses to therapy or the likelihood of familial disease. This is a test for mutations at codon V600 in the BRAF gene only. BRAF plus other genes are included in our full FIND-IT panel and focussed panels for colorectal cancer, lung cancer and melanoma.
Utility:
In metastatic melanoma, the presence of these mutations is associated with increased sensitivity to BRAF and MEK-inhibitor therapy. The absence of such mutations indicates that the patient's tumour is less likely to respond.
In colorectal cancer, presence of a BRAF mutation may be associated with prognosis, and with reduced likelihood of response to targeted therapy with anti-EGFR antibodies. In mismatch-repair deficient colorectal cancers, the absence of a BRAF mutation is associated with an increased probability of the patient having Lynch syndrome, an inherited DNA mismatch-repair deficiency.
Ethical considerations:
This is an assay for non-heritable mutations. It does not raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient.
Methodology:
Analysis of codon 600 of the BRAF gene.
Requesting the fest
Ordering:
This test is usually requested by a surgeon, oncologist or the pathologist providing the initial histopathology report. Please use the specific request form (see link below).
Request form:
Download the somatic mutation request form.
Sample required:
Formalin-fixed, paraffin embedded tissue (FFPE) - 15 sections of 4 uM thickness, dried overnight at 37°C onto charged/coated slides.
Special instructions:
Please stain the first section with H&E, and label each slide with patient and block identifiers. Label the unstained sections sequentially (slides 2-15). The request should be accompanied by the somatic mutation request form (above) and a copy of the original histopathology report.
Turnaround time:
10 business days.
Price:
This test has a Medicare rebate which, subject to the requirements of the Medicare descriptor being met, may cover all or part of the cost.
Rebate:
The Medicare details, including descriptor and schedule fee, are listed under MBS item 73336.