Cytogenetically-Normal AML (CN-AML) Prognostic Markers
Cytogenetic analysis is the initial test for risk stratification in AML. Although 50% of AML cases are cytogenetically normal (CN-AML) and considered to be intermediate risk, single gene mutations exist that provide subtype stratification within this risk group. Use of these new molecular markers in CN-AML may provide better prognostication and aid in determination of therapeutic regimens. For prognostication purposes, all markers should be interpreted as a group and not individually.
Extracted DNA/RNA can be stored from original samples and used for additional testing after determination of initial cytogenetic risk classification.
For molecular markers in CN-AML, see table below.
| MOLECULAR MARKERS IN CN-AML | ||
|---|---|---|
Marker | Biology | Prognosis |
Well-Characterized Markers | ||
NPM1 mutation ARUP available tests: | Nucleolar phosphoprotein that shuttles between nucleus and cytoplasm | NPM1 mutations associated with favorable outcome |
CEPBA mutations ARUP available tests: | Transcription factor involved in myeloid differentiation | Double CEPBA mutations associated with favorable outcome Single CEPBA mutations have unclear clinical significance |
FLT3 mutations ARUP available tests: | Tyrosine kinase receptor expressed by hematopoietic progenitor cells that regulates cell survival and maturation | FLT3 internal tandem mutations (ITD) associated with unfavorable outcome FLT3 D385 (tyrosine kinase domain mutations) associated with unfavorable outcome |
Investigational Markers | ||
IDH1 mutation, IDH2 mutation | Enzyme involved in citric acid cycle Mutations cause neomorphic activity that leads to production of the onco metabolite 2-hydroxyglutarate | IDH1 SNP rs11554137 associated with unfavorable outcome, particularly if associated with FLT3 or NMP1 wild type mutations |
WT1 mutation ARUP available tests: | Transcription factor expressed in embryonic kidney cells and hematopoietic cells that has both tumor suppressor and oncogenic functions | Mutations of exon 7 or 9 associated with unfavorable outcome G-allele of SNP rs16754 in exon 7 associated with improved outcome in patients with FLT3 and wild-type NPM1 |
DNMT3A mutation | Encodes for methyltransferases Mutations cause reduced enzymatic activity with aberrant DNA methylation | DNMT3A mutation associated with unfavorable outcome |
BAALC overexpression | Expressed in CD34 positive hemopoietic progenitors and neural tissue; functions in cytoskeleton | Overexpression associated with unfavorable outcome |
MLL partial tandem duplication (PTD) mutations, overexpression | Involved in chromatin modification | MLL PTD associated with less favorable outcome |
BAALC – brain and acute leukemia, cytoplasmic; CEPBA – CAAT/enhancer binding protein (C/EBP) α; DNMT3A – DNA (cytosine-5-)-methyltransferase 3 alpha; FLT3 – FMS-related tyrosine kinase 3; IDH1 – isocitrate dehydrogenase 1 (NADP+), soluble; IDH2 – isocitrate dehydrogenase 2 (NADP+), mitochondrial; MLL – myeloid/lymphoid or mixed-lineage leukemia; NPM1 – nucleophosmin (nucleolar phosphoprotein B23, numatrin); WT1 – Wilms tumor 1 Dohner, H, 2011; Lin et al, 2011; Watt et al, 2010. | ||
Acute myeloid leukemia (AML) is a malignant neoplasm of hematopoietic bone marrow precursor cells and is the most common type of acute leukemia in adults. Acute leukemias phenotypically represent immature hematopoietic cells but often display differences from normal cell counterparts.
| Test Name and Number | Recommended Use | Limitations | Follow Up |
|---|---|---|---|
| Chromosome Analysis, Leukemic Blood 2002290 Method: Giemsa Band |
Detect chromosome abnormalities in peripheral blood consistent with diagnosis of AML Prognosticate in AML |
Number of dividing cells in the peripheral blood may be insufficient to allow for full analysis of metaphase cells; bone marrow aspirate may be more informative |
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| Chromosome Analysis, Bone Marrow 2002292 Method: Giemsa Band |
Detect chromosome abnormalities in peripheral blood consistent with diagnosis of AML Prognosticate in AML |
Repeat testing as clinically indicated to monitor disease progression |
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| Leukemia/Lymphoma Phenotyping (Comprehensive - Whole Blood) 0096299 Method: Flow Cytometry |
Detect chromosome abnormalities in peripheral blood consistent with diagnosis of AML Prognosticate in AML |
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| Leukemia/Lymphoma Phenotyping (Comprehensive - Bone Marrow) 0095244 Method: Flow Cytometry |
Detect chromosome abnormalities in peripheral blood consistent with diagnosis of AML Prognosticate in AML |
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| Cytogenomic SNP Microarray - Oncology 2006325 Method: Genomic Microarray (Oligo-SNP Array) |
Detect chromosome abnormalities in peripheral blood consistent with diagnosis of AML Prognosticate in AML |
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| Chromosome FISH, Interphase 2002298 Method: Fluorescence in situ Hybridization |
Use to detect diagnostic and prognostic abnormalities Monitor disease and identify specific abnormalities suspected clinically Specific FISH probes must be requested; for this indication include t(15;17), t(8;21), inv(16), 11q23 rearrangements, monosomy 7 or 7q deletion, 5q deletion, +8, and 20q deletion Indicate names of probes needed for testing ARUP Oncology FISH Probes menu |
Limit of detection is probe dependent and ~2-5% in interphase nuclei; residual disease levels lower than this will likely appear normal Some of these abnormalities can also be detected in MDS and MPN and therefore are not by themselves sufficient for diagnosis but rather consistent with the suspected diagnosis |
Repeat testing as clinically indicated to monitor disease progression |
| Acute Myelogenous Leukemia Panel by FISH 2002384 Method: Fluorescence in situ Hybridization |
Identify prognostically important translocations in newly diagnosed AML Probes included are RUNX1T1-RUNX1, MLL, and CBFβ PML-RARα performed and reported separately |
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| Acute Myelogenous Leukemia (AML) with Myelodysplastic Syndrome (MDS), or Therapy-Related AML, by FISH 2002653 Method: Fluorescence in situ Hybridization |
Provides prognostic information for patients with AML arising in the setting of MDS or patients with therapy-related MDS/AML Test also aids in monitoring response to therapy or progression of disease EGR1 (5q del), D7S486 (7q del/-7), MLL probes are included |
Chromosome alterations outside regions complementary to these probes are not detected |
|
| PML/RARa FISH 2002363 Method: Fluorescence in situ Hybridization |
Use to diagnose promyelocytic leukemia by detection of t(15;17) |
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| PML-RARA Translocation, t(15;17) by RT-PCR, Quantitative 2002871 Method: Reverse Transcription Polymerase Chain Reaction |
Identify PML-RARα fusion transcript in diagnosis of promyelocytic leukemia Primer sets are designed to detect all 3 gene fusion patterns: type A (short, S-form, bcr-3), type B (long, L-form, bcr-1) and type B variant (variable, V-form, bcr-2) |
Limit of detection is 1/1,000 cells; does not detect minimal residual disease |
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| CBFB-MYH1, inv(16) by RT-PCR 0092209 Method: Reverse Transcription Polymerase Chain Reaction |
Diagnose AML with abnormal bone marrow eosinophils and inv(16) |
Test not intended to detect minimal residual disease Should not be used alone for diagnosis of malignancy Negative result does not preclude presence of CBFB-MYH11 fusion transcripts below limit of detection or presence of type other than A, D or E |
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| RUNX1-RUNX1T1 (AML1-ETO) Translocation, t(8;21) by RT-PCR 0050444 Method: Reverse Transcription Polymerase Chain Reaction |
Identify type of AML Monitor minimal residual disease |
Negative result does not exclude the presence of the t(8;21) Test result must always be interpreted in the context of morphologic and other relevant data and should not be used alone for a diagnosis of malignancy |
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| CEBPA Mutation Detection 2004247 Method: Polymerase Chain Reaction/Sequencing |
Prognosis in CN-AML |
Negative result does not preclude the presence of CEBPA mutations in rare AML cells below the detection limit of this test | |
| NPM1 Mutation by PCR and Fragment Analysis, Fluid 0040174 Method: Polymerase Chain Reaction/Fragment Analysis |
Prognosis in CN-AML |
Should not be used alone for diagnosis of malignancy Negative result does not preclude the presence of NPM1 mutations in rare AML cells below the detection limit of this test |
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| NPM1 Mutation by PCR and Fragment Analysis, Paraffin 0040179 Method: Varies |
Prognosis in CN-AML |
Should not be used alone for diagnosis of malignancy Negative result does not preclude the presence of NPM1 mutations in rare AML cells below the detection limit of this test |
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| FLT3 Mutation Detection by PCR 2005400 Method: Qualitative Polymerase Chain Reaction/Capillary Electrophoresis |
Prognosis in CN-AML |
Negative result does not exclude presence of FLT3 gene mutation Assay is a qualitative test and should not be used to detect minimal residual disease Should not be used alone for diagnosis of malignancy |
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| KIT Mutations in AML by Fragment Analysis and Sequencing 2002437 Method: Polymerase Chain Reaction/Fragment Analysis/Sequencing |
Prognosis cytogenetically abnormal AML with t(8;21) or inv(16) |
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| WT1 Mutation Detection by Sequencing 2005766 Method: Polymerase Chain Reaction/Sequencing |
Prognosis in CN-AML |
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| CD19 by Immunohistochemistry 2005114 Method: Immunohistochemistry |
Aid in histologic diagnosis of B-cell leukemia/lymphoma Stained and returned to client pathologist for interpretation; consultation available if needed |
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| CD34, QBEnd/10 by Immunohistochemistry 2003556 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| CD68, KP1 by Immunohistochemistry 2003598 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| CD79A by Immunohistochemistry 2003800 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| CD117 (c-Kit) by Immunohistochemistry 2003806 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| Myeloperoxidase (MPO) by Immunohistochemistry 2004014 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| Pax-5 by Immunohistochemistry 2004082 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| Lysozyme (Muramidase) by Immunohistochemistry 2003990 Method: Immunohistochemistry |
Aid in the histologic diagnosis of AML Stained and returned to client pathologist for interpretation; consultation available if needed |
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| Eosinophilia Panel by FISH 2002378 Method: Fluorescence in situ Hybridization |
Diagnose/provide prognostic information in patients with AML with eosinophilia Probes include PDGFRα, PDGFRβ, FGFR1 and CBFB |