Use of test
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 focused panels for colorectal cancer, lung cancer and melanoma.
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.
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.
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
This test is usually requested by an oncologist. Please use the specific request form (see link below).
Formalin-fixed, paraffin embedded tissue (FFPE) - 15 sections of 4 uM thickness, dried overnight at 37°C onto charged/coated slides.
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.
5-10 business days.
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.
The Medicare details, including descriptor and schedule fee, are listed under MBS item 73338.
Click here for our billing policy.