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Prior Authorization Required*
*If prior authorization is not submitted, test may be delayed.
Test Overview
Test Methodology

Next-Generation Sequencing

Test Usage

RET encodes a receptor tyrosine kinase involved neural crest development. Oncogenic RET mutations occur frequently in medullary thyroid carcinoma (MTC). Approximately 50-60% of sporadic MTC harbor somatic RET mutations. The presence of these mutations is associated with an inferior prognosis and more aggressive disease. Germline RET mutations are associated with multiple endocrine neoplasia (MEN) 2 or familial medullary thyroid carcinoma. Multi-kinase inhibitors (MKI) including vandetanib and cabozantinib are FDA-approved for the treatment of metastatic or unresectable MTC (regardless of RET mutation status). Reported response rates to these agents range from 20%-45%. These drugs are often associated with toxicities – some (e.g. impaired wound healing, fistula formation, hemorrhage) related to inhibition of other tyrosine kinases, particularly vascular endothelial growth factor receptor 2 (VEGFR-2). Several selective tyrosine kinase inhibitors (TKI) with much greater RET inhibitory potency have been developed including LOXO-292, BLU-667 and RXDX-105. These drugs have shown promising efficacy with significantly lower toxicity in RET-mutated MTC.

Reference Range *

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Monday – Thursday
Analytic Time

5-12 days

Soft Order Code
MiChart Code
RET Mutation in Malignancy
Molecular Diagnostics
Molecular Diagnostics
Specimen Requirements
Collection Instructions

For formalin-fixed, paraffin-embedded tissue, a block containing an area with a high percentage of neoplastic cells (for micro-/macro-dissection) is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted, however these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature. A Diff-Quik or Papanicolaou stained aspirate smear (preferable containing a high percentage and overall amount of neoplastic cells) is also acceptable. Store at room temperature.

Normal Volume
Formalin-fixed, paraffin-embedded tissue; Diff-Quik stained aspirate smear, Papanicolaou stained aspirate smear.Extracted DNA is also acceptable if extracted in a CLIA certified laboratory.
Additional Information
Exon Codons GenBank Accession # Chromosome Hg19 Start Hg19 Stop
10 607-626 NM_020975.4 chr10 43,609,067 43,609,126
11 627-656 NM_020975.4 chr10 43,609,925 43,610,010
13 763-787 NM_020975.4 chr10 43,613,818 43,613,893
15 876-910 NM_020975.4 chr10 43,615,547 43,615,654
16 911-924 NM_020975.4 chr10 43,617,391 43,617,433

By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

CPT Code
81404, 88381-TC
Fee Code
NA096, NA037
Pro Fee CPT
G0452-26, 88381-26
NY State Approved