Microsatellite Instability (MSI)

Test Code

14989

Preferred Specimen

Formalin-fixed, paraffin-embedded tissue collected in a paraffin block bag

Minimum Volume

1 tissue block • 0.03 mL extracted DNA

Other Acceptable Specimens

0.03 mL extracted DNA collected in a sterile leak-proof container

Instructions

Tissue: One formalin-fixed, paraffin-embedded tissue with representative Tumor. Pathology report is required.

Extracted DNA: Extracted DNA from CLIA-certified laboratory submitted in a sterile leak-proof container. DNA is to be shipped frozen. Do not thaw. Minimum and absolute minimum volume is 0.03 mL. Ship DNA immediately after extraction is performed. DNA must remain frozen until testing.

Transport Temperature

FFPE block: Room temperature
DNA: Frozen

Specimen Stability

FFPE block
Room temperature: 5 years
Refrigerated: 5 years
Frozen: Unacceptable

DNA
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: See instructions

Methodology
Capillary Electrophoresis • Polymerase Chain Reaction (PCR)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Wed, Sat; Report available: 3-4 days

Reference Range

See Laboratory Report

Clinical Significance

Patients with early onset and family history of colon cancers are suggestive of hereditary nonpolyposis colon cancer (hnpcc) syndrome. Microsatellite instability analysis on tumor tissue is recommended as a screening test to identify individuals eligible for germline mutation analysis or mismatch repair genes. Microsatellite instability analysis can also be used to identify adult and pediatric patients with unrespectable or metastatic solid tumors who have failed frontline therapy and who would be candidates for targeted immune therapy with Keytruda (Pembrolizumab).

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.