Test Catalog

Test Id : TMSI

Microsatellite Instability, Tumor

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluation of tumor tissue to identify patients at high risk for having Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer

 

Evaluation of tumor tissue for clinical decision-making purposes given the prognostic and therapeutic implications associated with microsatellite instability phenotypes

Additional Tests
Lists tests that are always performed, at an additional charge, with the initial tests.

Test Id Reporting Name Available Separately Always Performed
SLIRV Slide Review in MG No, (Bill only) Yes

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, slide review will always be performed at an additional charge.

 

See Lynch Syndrome Testing Algorithm

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Polymerase Chain Reaction (PCR)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Tumor, Microsatellite Instability

Aliases
Lists additional common names for a test, as an aid in searching

DNA Mismatch Repair-related HNPCC

Hereditary Nonpolyposis Colon Cancer (HNPCC)

Lynch syndrome

Lynch

Microsatellite Instability

MSI

Tumor microsatellite Instability

MMR

Mismatch repair

Mismatch repair deficiency

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, slide review will always be performed at an additional charge.

 

See Lynch Syndrome Testing Algorithm

Specimen Type
Describes the specimen type validated for testing

Varies

Necessary Information

Pathology report must accompany specimen in order for testing to be performed.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

This assay requires at least 40% tumor nuclei for endometrial specimens and at least 20% tumor nuclei for colorectal specimens

-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue 72 mm(2)

-Minimum amount of tumor area: 18 mm(2)

-These amounts are cumulative over up to 10 unstained slides and must have adequate percent tumor nuclei.

-Tissue fixation: formalin-fixed paraffin-embedded (FFPE), non-decalcified

 

Preferred:

Specimen Type: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.

 

Acceptable:

Specimen Type: Tissue slide

Slides: 1 stained and 5 unstained

Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 5 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.

Note: The total amount of required tumor nuclei can be obtained by scraping up to 5 slides from the same block.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

1. Molecular Genetics: Inherited Cancer Syndromes Patient Information (T519).

2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

    Gastroenterology and Hepatology Client Test Request (T728)

    Oncology Test Request (T729)

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Decalcified specimens
Low tumor percentage
Insufficient amount of tumor
Nonformalin-fixed
Fresh tissue
Cytology smears
Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
Frozen
Refrigerated

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluation of tumor tissue to identify patients at high risk for having Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer

 

Evaluation of tumor tissue for clinical decision-making purposes given the prognostic and therapeutic implications associated with microsatellite instability phenotypes

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, slide review will always be performed at an additional charge.

 

See Lynch Syndrome Testing Algorithm

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Somatic (tumor-specific) microsatellite instability (MSI) is assessed by this test. MSI is characterized by numerous alterations in a type of repetitive DNA called microsatellites and occurs as the result of an impaired DNA mismatch repair process. Impaired DNA mismatch repair is a key factor in tumorigenesis and can occur sporadically or as the result of a hereditary cancer predisposition called Lynch syndrome.

 

Evaluation for MSI may be valuable for clinical decision making. Current data suggest that advanced stage solid tumors with defective DNA mismatch repair (MSI-H) are more likely to respond to treatment with immunotherapies such as anti-PD-1 therapies. Colon cancers that demonstrate defective DNA mismatch repair (MSI-H) have a significantly better prognosis compared to those with intact mismatch repair (MSS/MSI-L). Additionally, current data indicate that stage II and stage III patients with colon cancers characterized by the presence of defective mismatch repair (MSI-H) may not benefit from treatment with fluorouracil alone or in combination with leucovorin. These findings are most likely to impact the management of patients with stage II disease.

 

MSI analysis, usually in combination with immunohistochemistry staining of the mismatch repair proteins, can also provide helpful diagnostic information in the context of evaluation for Lynch syndrome. See Lynch Syndrome Testing Algorithm.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

The report will include specimen information, assay information, and interpretation of test results.

 

Microsatellite stable (MSS) is reported as MSS (0 or 1 of 7 markers demonstrating instability) or microsatellite instability-high (MSI-H) (2 or more of 7 markers demonstrating instability).

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The finding of tumor microsatellite instability does not distinguish between somatic and germline alterations.

 

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in our interpretation of results may occur if information given to us is inaccurate or incomplete.

Supportive Data

A total of 100 accuracy samples were run retrospectively during verification; 55/100 samples were colorectal, 41/100 were endometrial, and the remaining 4/100 were other tumor types. The overall concordance between the Idylla and Promega results was 98/100 (98%). Seventy-nine of 100 samples were microsatellite stable (MSS) by Promega and 77 (97%) had concordant MSS results by Idylla. Twenty-one of 100 samples were microsatellite instability-high (MSI-H) by Promega and 21 (100%) had concordant MSI-H results by Idylla.

 

In addition to the retrospective samples, 100 consecutive samples were prospectively analyzed, of which 58 were colorectal, 31 were endometrial, and 11 were from other tumor types. Seventy-six of 100 samples were MSS by Promega and all (100%) were MSS by the Idylla assay. Twenty-four of 100 samples were MSI-H by Promega. Twenty-three of 24 (96%) of the MSI-H samples were concordant by Idylla. One patient had an uncommon reason for referral (RFR). The discordant sample DNA was rerun on the Promega platform, but there was not sufficient tissue remaining to rerun this specimen on the Idylla assay. After reviewing the results from the 2 runs on Promega, a consensus decision amongst 5 pathologists was reached and the sample was reclassified as equivocal by the Promega assay.

 

Precision and reproducibility was evaluated by running 3 MSI-H samples and 3 MSS samples in triplicate on the same instrument. Each of these samples had a 4th cartridge run on a separate instrument. There was 100% concordance between replicates from the 3 MSI-H samples and 3 MSS samples.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Baudhuin LM, Burgart LJ, Lentovich O, Thibodeau SN: Use of microsatellite instability and immunohistochemistry testing for the identification of individuals at risk for Lynch syndrome. Fam Cancer. 2005;4 (3):255-265

2. Terdiman JP, Gum JR Jr, Conrad PG, et al: Efficient detection of hereditary nonpolyposis colorectal cancer gene carriers by screening for tumor microsatellite instability before germline genetic testing. Gastroenterology. 2001 January;120(1):21-30

3. Popat S, Hubner R, Houlston RS: Systematic review of microsatellite instability and colorectal cancer prognosis. J Clin Oncol. 2005 Jan; 23(3):609-618

4. Ribic CM, Sargent DJ, Moore MJ, et al: Tumor microsatellite-instability status as a predictor of benefit from fluorouracil-based adjuvant chemotherapy for colon cancer. N Engl J Med. 2003 Jul 17;349:247-257

5. Kohlmann W, Gruber SB. Lynch syndrome. In: Adam MP, Ardinger HH, Pagon RA, et al. eds. GeneReviews [Internet]. University of Washington, Seattle; 2004. Updated April 12, 2018. Accessed June 22, 2020. Available at www.ncbi.nlm.nih.gov/books/NBK1211/

6. Kawakami H, Zaanan A, Sinicrope FA: Microsatellite instability testing and its role in the management of colorectal cancer. Curr Treat Options Oncol. 2015 Jul;16(7):30

7. Sargent DJ, Marsoni S, Monges G, et al: Defective mismatch repair as a predictive marker for lack of efficacy of fluorouracil-based adjuvant therapy in colon cancer. J Clin Oncol. 2010 Jul 10;28(20):3219-3226

8. Le DT, Durham JN, Smith KN, et al: Mismatch repair deficiency predicts response of solid tumors to PD-1 blockade. Science. 2017 Jul 28;357(6349):409-413

9. Overman MJ, Lonardi S, Wong KYM, et al: Durable clinical benefit with nivolumab plus ipilimumab in DNA mismatch repair-deficient/microsatellite instability-high metastatic colorectal cancer. J Clin Oncol. 2018 Mar 10;36 (8):773-779

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

The Idylla is a fully-automated real-time polymerase chain reaction based molecular testing system that uses formalin-fixed, paraffin-embedded slides. This assay detects a novel panel of 7 monomorphic biomarkers (ACVR2A, BTBD7, DIDO1, MRE11, RYR3, SEC31A, SULF2) to evaluate microsatellite instability status without need for normal (noncancerous) tissue from each patient.(Package insert: Idylla MSI Assay. Biocartis NV; 05/2018)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

60 days for FFPE slides

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

81301

88381-Microdissection, manual

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
TMSI Tumor, Microsatellite Instability 81711-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
609365 Result Summary 50397-9
609366 Result 43368-0
609367 Interpretation 69047-9
609368 Specimen 31208-2
609369 Source 31208-2
609370 Tissue ID 80398-1
609371 Released By 18771-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports