Mutation Tests
Overview
Pathwork Diagnostics Laboratory offers KRAS, BRAF and EGFR mutation testing to help determine whether patients will respond to targeted therapies.
All tests are performed in Pathwork Diagnostic’s CAP accredited, CLIA-certified laboratory using an allele-specific real time (RT) PCR assay.
The table below summarizes how the mutation test results are commonly used for selecting targeted therapies.
| Mutation | Non-small cell lung cancer | Colorectal cancer | Melanoma |
|---|---|---|---|
| EGFR mutation positive | Tumors more likely to be sensitive to first-line therapy with tyrosine kinase inhibitors (TKI) - Tarceva (erlotinib) and Iressa (gefitinib).A,B | ||
| EGFR mutation negative | Tumors more likely to be resistant to first-line therapy with tyrosine kinase inhibitors (TKI) - Tarceva (erlotinib) and Iressa (gefitinib). Studies suggest patients will receive greater benefits fron other chemotherapy.B | ||
| KRAS mutation positive | Tumors more likely to be resistant to tyrosine kinase inhibitors (TKI) - Tarceva (erlotinib) and Iressa (gefitinib). Therapy other than TKI therapy should be considered first for mutation-positive tumors.A | Tumors are resistant to anti-EGFR targeted therapies such as Erbitux (cetuximab) or Vectibix (panitumumab).A | |
| KRAS mutation negative |
Tumors may respond to anti-EGFR targeted therapies for first line treatment. Consider BRAF test.A |
||
| BRAF V600E mutation positive | Tumors may be resistant to anti-EGFR targeted therapies.A | Tumors sensitive to BRAF inhibitor Zelboraf (vemurafenib).A | |
| BRAF V600E mutation negative | Tumors negative for both BRAF and KRAS mutations may benefit from anti-EGFR targeted therapies.A |
A.Refer to NCCN Guidelines at www.NCCN.org
B.Keedy, V, Temin S, et al: American Society of Clinical Oncology Provisional Clinical Opinion: Epidermal Growth Factor Receptor (EGFR) Mutation Testing for Patients with Advanced Non-Small-Cell Lung Cancer Considering First-Line EGFR Tyrosine Kinase Inhibitor Therapy. J Clin Oncol 29(15): 2121-2127, 2011.