Alternative Name
AR Mutation Analysis
Methodology
Molecular
Test Description
Bi-directional Sanger sequencing of the gene Androgen Receptor is performed using PCR primers designed to target hotspot mutations in exons 4, 5 and 8.
Clinical Significance
Androgen deprivation therapy (ADT) is very important therapeutic approach in the treatment of metastatic prostate cancer. Most of the current androgen deprivation drugs target the ligand binding domain (LBD) of the androgen receptor (AR). However, mutations in the AR gene as well as the expression of alternatively-spliced AR variant 7 (AR-V7) that lack the LBD lead to resistance to ADT. Furthermore, constitutional variations (mutations) and acquired mutations in AR lead to higher expression of the AR-V7 in castration-resistant prostate cancer. AR-V7 is inducible and detectable while the patient is on ADT. Our test is designed to predict resistance to enzalutamide and abiraterone in castration-resistant prostate cancers, irrespective if they are on therapy or not. This testing is recommended along with PTEN deletion testing by FISH for evaluating prognosis. Mutation analysis of the full AR coding sequence is available as a part of our NeoTYPE Discovery panel.
Specimen Requirements
FFPE solid tumor tissue: Paraffin block is preferred. Alternatively, send 1 H&E slide plus 5-10 unstained slides cut at 5 or more microns. Please use positively-charged slides and 10% NBF fixative. Do not use zinc fixatives.
Storage and Transportation
Use cold pack for transporting block during summer to prevent block from melting. Slides can be packed at room temperature.
CPT Code(s)*
81204
Turnaround Time
14 days
Level of Service
Global

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.