KRAS and NRAS screen
Also known as: RAS panel, KRAS and NRAS gene test
Test category:
Oncology - Colorectal cancer
Use of test
Purpose:
The presence of specific activating mutations in the KRAS and NRAS genes in certain malignancies (for example, metastatic colorectal cancer) indicates a reduced likelihood of treatment response to anti-EGFR therapy.
This is a test for mutations in the KRAS and NRAS genes only. Combinations of KRAS, NRAS and other genes are included in our full FIND-IT panel and focussed panels for colorectal cancer, lung cancer and melanoma.
Utility:
A normal test result (no mutations) indicates that the patient's tumour is likely to respond to anti-EGFR therapies. An abnormal test result (specific mutations identified) indicates that the tumour is likely to be resistant to anti-EGFR therapies.
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:
Testing of targeted mutations in the KRAS and NRAS genes (at codons 12, 13, 59, 61, 117 and 146 in both genes).
Requesting the test
Ordering:
This test is usually requested by an oncologist. Please use the specific request form (see link below).
Request Form:
Link to 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:
5-10 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 73338.