Glioma subclassification, prognosis and selection of therapies
This test includes a charge for application of 2 probe sets (4 individual fluorescence in situ hybridization probes), analysis, and professional interpretation of results.
Fluorescence In Situ Hybridization (FISH)
Brain
Brain Cancer
Glioma
1p/19q
Oligodendroglioma
This test includes a charge for application of 2 probe sets (4 individual fluorescence in situ hybridization probes), analysis, and professional interpretation of results.
Tissue
To evaluate for acquired alterations associated with the molecular classification of glioma, chromosomal microarray rather than fluorescence in situ hybridization may be of benefit, order CMAPT / Chromosomal Microarray, Tumor, Formalin-Fixed Paraffin-Embedded.(1)
Advise Express Mail or equivalent if not on courier service.
Ship paraffin blocks on ice packs during warm months.
A reason for testing and pathology report are required for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology, or surgical pathology reports.
Submit only 1 of the following specimens:
Specimen Type: Tissue
Preferred: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tumor tissue block. Blocks prepared with alternative fixation methods will not be accepted; provide fixation method used.
Note: Send with ice pack if shipping during warm months.
Acceptable: Slides
Collection Instructions: Three consecutive, unstained, 4 to 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Tissue slides: 2 consecutive unstained and 1 hematoxylin and eosin stained
Decalcified specimens | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Tissue | Ambient (preferred) | ||
Refrigerated |
Glioma subclassification, prognosis and selection of therapies
This test includes a charge for application of 2 probe sets (4 individual fluorescence in situ hybridization probes), analysis, and professional interpretation of results.
Chromosome 1p/19q co-deletion is a diagnostic and prognostic marker of oligodendroglioma. Studies have shown that the co-deletion of these 2 chromosomal arms is due to a balanced whole arm translocation between chromosomes 1 and 19 and subsequent loss of the 1p and 19q arms. Detection of 1p/19q co-deletion along with molecular testing of other genes including MGMT promotor methylation, IDH1/2 variant, TERT promotor variants, as well as TP53 variants, will assist glioma classification and predicting prognosis and providing a guidance for treatment. Variants in many other genes may occur and detection of these by next generation sequencing may provide useful information for classification and therapeutic consideration.
1p/19q co-deletion is determined by fluorescence in situ hybridization (FISH) in this test. Interpretation of the clinical significance of the FISH result should be correlated with the results of other molecular testing for disease subclassification and therapy selection. While IDH1/2 variants with co-deletion of 1p and 19q define oligodendrogliomas, isolated 19q loss is common in astrocytomas and focal loss of 1p frequently is seen in IDH-wild-type glioblastoma. Rarely, a 1p/19q co-deletion detected by FISH may not represent loss of the whole chromosome 1p and 19q arms. If a positive FISH result is not consistent with the disease subclassification, additional tests such as chromosome microarray should be considered to confirm presence of 1p/19q whole arm loss.
An interpretive report will be provided.
While IDH1/2 variantss with co-deletion of 1p and 19q define oligodendrogliomas, isolated 19q loss is common in astrocytomas and focal loss of 1p frequently is seen in IDH wildtype glioblastoma. Interpretation of the fluorescence in situ hybridization result must be correlated with other molecular testing results.
Optimum fixation should be performed in 10% neutral buffered formalin. Other types of fixatives should not be used.
The information provided by the 1p/19q status of a patient's tumor should not be interpreted in isolation.
1. Eckel Passow JE, Lachance DH, Molinaro AM, et al: Glioma Groups Based on 1p/19q, IDH, and TERT Promoter Mutations in Tumors. N Engl J Med. 2015;372(26):2499-2508
2. Weller M, Wick W, Aldape K, et al. Glioma. Nat Rev Dis Primers. 2015;1:15017
3. Reifenberger G, Wirsching HG, Knobbe-Thomsen CB, Weller M. Advances in the molecular genetics of gliomas implications for classification and therapy. Nat Rev Clin Oncol. 2017;14(7):434-452
4. Chen R, Smith-Cohn M, Cohen AL, Colman H. Glioma Subclassifications and Their Clinical Significance. Neurotherapeutics 2017;14(2):284-297
5. Nicholson JG, Fine HA. Diffuse Glioma Heterogeneity and Its Therapeutic Implications. Cancer Discov. 2021;11(3):575-590
6. Galbraith K, Snuderl M. Molecular Pathology of Gliomas. Surg Pathol Clin. 2021;14(3):379-386
The test uses 2 commercially available enumeration strategy probe sets: 1p36(TP73)/1q25(ABL2) and 19p13(D19S221)/19q13.3(EHD2). Formalin-fixed paraffin-embedded tissues cut at 4 to 5 microns and mounted on positively charged glass slides are used. The selection of tissue and the identification of target areas on the hematoxylin and eosin (H and E)-stained slide is performed by a pathologist. Using the H and E-stained slide as a reference, target areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. The probe sets are hybridized to the appropriate target areas. For each probe set, 2 technologists each analyze 50 interphase nuclei (100 total for each probe set) with the results expressed as a ratio of the total number of 1p36:1q and 19q13.3:19p signals.(Unpublished Mayo method)
Monday through Friday
This test was developed using an analyte specific reagent. Its performance characteristics were 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.
88377 x 2 (2 probe sets)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
JGLIF | 1p/19q Deletion, Glioma, FISH, Tis | In Process |
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.
|
---|---|---|
606667 | Result Summary | 50397-9 |
606668 | Interpretation | 69965-2 |
606669 | Result | 62356-1 |
606670 | Reason for Referral | 42349-1 |
606671 | Specimen | 31208-2 |
606672 | Source | 85298-8 |
606673 | Tissue ID | 80398-1 |
606674 | Fixative | 8100-0 |
606675 | Method | 85069-3 |
606676 | Additional Information | 48767-8 |
606677 | Disclaimer | 62364-5 |
606678 | Released By | 18771-6 |
Change Type | Effective Date |
---|---|
New Test | 2024-11-04 |