B lymphoblastic leukaemia/lymphoma with TCF3::PBX1 fusion

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Haematolymphoid Tumours (5th ed.)

editHAEM5 Conversion Notes
This page was converted to the new template on 2023-12-04. The original page can be found at HAEM4:B-Lymphoblastic Leukemia/Lymphoma with t(1;19)(q23;p13.3); TCF3-PBX1.

Primary Author(s)*

Binu Porath, PhD. Vanderbilt University Medical Center, Nashville, TN

Linda D. Cooley, MD, MBA. Children's Mercy Kansas City, Kansas City, MO

Cancer Category / Type

B-Lymphoblastic Leukemia/Lymphoma

Cancer Sub-Classification / Subtype

B-Lymphoblastic Leukemia/Lymphoma with t(1;19)(q23;p13.3); TCF3-PBX1

Definition / Description of Disease

Neoplasm of B-cell lineage precursor lymphoblasts where the blasts contain a translocation between PBX1 at 1q23 and TCF3 at 19p13.3.[1]

Synonyms / Terminology

TCF3 is also known as E2A.

Epidemiology / Prevalence

The t(1;19) translocation is present in ~5% pediatric and ~3% adult B-ALL cases. The incidence of this translocation does not vary significantly with age, however, there is a high incidence (~12%) of this rearrangement in African-American children with B-ALL.[2]

Clinical Features

Put your text here and fill in the table (Instruction: Can include references in the table)

Signs and Symptoms EXAMPLE Asymptomatic (incidental finding on complete blood counts)

EXAMPLE B-symptoms (weight loss, fever, night sweats)

EXAMPLE Fatigue

EXAMPLE Lymphadenopathy (uncommon)

Laboratory Findings EXAMPLE Cytopenias

EXAMPLE Lymphocytosis (low level)


editv4:Clinical Features
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No unique clinical features that distinguish this entity from other types of B-ALL. Common clinical features of B-ALL include:

  • Fatigue
  • Infections
  • Easy bruising/bleeding

Other symptoms present may include:

  • Achiness
  • Fever
  • Night sweats
  • Weight loss

These features manifest clinically as anemia, neutropenia, and/or thrombocytopenia. [2]

Sites of Involvement

Bone marrow, Blood, Central Nervous System (CNS) [2]

Morphologic Features

There are no unique morphological features that distinguish this entity from other types of ALL.[1]

Immunophenotype

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Finding Marker
Positive (universal) EXAMPLE CD1
Positive (subset) EXAMPLE CD2
Negative (universal) EXAMPLE CD3
Negative (subset) EXAMPLE CD4


editv4:Immunophenotype
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Blasts with pre-B phenotype, positive for CD19, CD10 and cytoplasmic mu heavy chain. [1]

Chromosomal Rearrangements (Gene Fusions)

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Chromosomal Rearrangement Genes in Fusion (5’ or 3’ Segments) Pathogenic Derivative Prevalence Diagnostic Significance (Yes, No or Unknown) Prognostic Significance (Yes, No or Unknown) Therapeutic Significance (Yes, No or Unknown) Notes
EXAMPLE t(9;22)(q34;q11.2) EXAMPLE 3'ABL1 / 5'BCR EXAMPLE der(22) EXAMPLE 20% (COSMIC)

EXAMPLE 30% (add reference)

Yes No Yes EXAMPLE

The t(9;22) is diagnostic of CML in the appropriate morphology and clinical context (add reference). This fusion is responsive to targeted therapy such as Imatinib (Gleevec) (add reference).


editv4:Chromosomal Rearrangements (Gene Fusions)
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The breakpoints of the t(1;19) translocation typically fall within intron 16 of TCF3 and intron 3 of PBX1. [2]

Chromosomal Rearrangement Genes in Fusion (5’ or 3’ Segments) Pathogenic Derivative Prevalence
t(1;19)(q23;p13.3) TCF3-PBX1 der(19) More common (75%)
t(1;19)(q23;p13.3) TCF3-PBX1 Balanced translocation Less common


editv4:Clinical Significance (Diagnosis, Prognosis and Therapeutic Implications).
Please incorporate this section into the relevant tables found in:
  • Chromosomal Rearrangements (Gene Fusions)
  • Individual Region Genomic Gain/Loss/LOH
  • Characteristic Chromosomal Patterns
  • Gene Mutations (SNV/INDEL)

The t(1;19) diagnosis was associated with high risk and poor prognosis in earlier studies, however, modern intensive chemotherapy has changed this paradigm. A recent (2021) study showed that patients with TCF3-PBX1 had intermediate rates of 5-year event-free survival (80-88.2%). Despite the favorable prognosis of this subtype of ALL, there is an increased relative risk of central nervous system relapse associated with this translocation. [1][2][3]

Individual Region Genomic Gain / Loss / LOH

Put your text here and fill in the table (Instructions: Includes aberrations not involving gene fusions. Can include references in the table. Can refer to CGC workgroup tables as linked on the homepage if applicable.)

Chr # Gain / Loss / Amp / LOH Minimal Region Genomic Coordinates [Genome Build] Minimal Region Cytoband Diagnostic Significance (Yes, No or Unknown) Prognostic Significance (Yes, No or Unknown) Therapeutic Significance (Yes, No or Unknown) Notes
EXAMPLE

7

EXAMPLE Loss EXAMPLE

chr7:1- 159,335,973 [hg38]

EXAMPLE

chr7

Yes Yes No EXAMPLE

Presence of monosomy 7 (or 7q deletion) is sufficient for a diagnosis of AML with MDS-related changes when there is ≥20% blasts and no prior therapy (add reference).  Monosomy 7/7q deletion is associated with a poor prognosis in AML (add reference).

EXAMPLE

8

EXAMPLE Gain EXAMPLE

chr8:1-145,138,636 [hg38]

EXAMPLE

chr8

No No No EXAMPLE

Common recurrent secondary finding for t(8;21) (add reference).

editv4:Genomic Gain/Loss/LOH
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Secondary somatic copy number aberrations are not frequently seen in TCF3-PBX1 B-ALL

Characteristic Chromosomal Patterns

Put your text here (EXAMPLE PATTERNS: hyperdiploid; gain of odd number chromosomes including typically chromosome 1, 3, 5, 7, 11, and 17; co-deletion of 1p and 19q; complex karyotypes without characteristic genetic findings; chromothripsis)

Chromosomal Pattern Diagnostic Significance (Yes, No or Unknown) Prognostic Significance (Yes, No or Unknown) Therapeutic Significance (Yes, No or Unknown) Notes
EXAMPLE

Co-deletion of 1p and 18q

Yes No No EXAMPLE:

See chromosomal rearrangements table as this pattern is due to an unbalanced derivative translocation associated with oligodendroglioma (add reference).

editv4:Characteristic Chromosomal Aberrations / Patterns
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The t(1;19) translocation can be balanced or unbalanced. The unbalanced form has a der(19) resulting in trisomy of 1q distal to PBX1.[4]

Gene Mutations (SNV / INDEL)

Put your text here and fill in the table (Instructions: This table is not meant to be an exhaustive list; please include only genes/alterations that are recurrent and common as well either disease defining and/or clinically significant. Can include references in the table. For clinical significance, denote associations with FDA-approved therapy (not an extensive list of applicable drugs) and NCCN or other national guidelines if applicable; Can also refer to CGC workgroup tables as linked on the homepage if applicable as well as any high impact papers or reviews of gene mutations in this entity.)

Gene; Genetic Alteration Presumed Mechanism (Tumor Suppressor Gene [TSG] / Oncogene / Other) Prevalence (COSMIC / TCGA / Other) Concomitant Mutations Mutually Exclusive Mutations Diagnostic Significance (Yes, No or Unknown) Prognostic Significance (Yes, No or Unknown) Therapeutic Significance (Yes, No or Unknown) Notes
EXAMPLE: TP53; Variable LOF mutations

EXAMPLE:

EGFR; Exon 20 mutations

EXAMPLE: BRAF; Activating mutations

EXAMPLE: TSG EXAMPLE: 20% (COSMIC)

EXAMPLE: 30% (add Reference)

EXAMPLE: IDH1 R123H EXAMPLE: EGFR amplification EXAMPLE:  Excludes hairy cell leukemia (HCL) (add reference).


Note: A more extensive list of mutations can be found in cBioportal (https://www.cbioportal.org/), COSMIC (https://cancer.sanger.ac.uk/cosmic), ICGC (https://dcc.icgc.org/) and/or other databases. When applicable, gene-specific pages within the CCGA site directly link to pertinent external content.


editv4:Gene Mutations (SNV/INDEL)
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Secondary somatic DNA mutations are not frequently seen in TCF3-PBX1 B-ALL. [2]

Other Mutations

Secondary somatic copy number aberrations and DNA mutations are not frequently seen in TCF3-PBX1 B-ALL, commonly found additional abnormalities are listed below. [2][4]

Type Gene/Region/Other
Additional abnormalities dup(1q), del(6q), +8, i(9q), i(17q), +21

Epigenomic Alterations

Put your text here

Genes and Main Pathways Involved

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Gene; Genetic Alteration Pathway Pathophysiologic Outcome
EXAMPLE: BRAF and MAP2K1; Activating mutations EXAMPLE: MAPK signaling EXAMPLE: Increased cell growth and proliferation
EXAMPLE: CDKN2A; Inactivating mutations EXAMPLE: Cell cycle regulation EXAMPLE: Unregulated cell division
EXAMPLE:  KMT2C and ARID1A; Inactivating mutations EXAMPLE:  Histone modification, chromatin remodeling EXAMPLE:  Abnormal gene expression program
editv4:Genes and Main Pathways Involved
The content below was from the old template. Please incorporate above.

TCF3 gene at 19p13.3 is important during early lymphocyte development, whereas PBX1 at 1q23 is a component of a transcriptional complex that regulates embryogenesis and hematopoiesis. Fusion protein resulting from the TCF3-PBX1 translocation is a transcriptional activator which likely interferes with the normal function of these genes. Expression of this fusion protein is thought to interfere with key regulatory pathways such as WNT and apoptosis/cell cycle control pathways which may drive a leukemic process. The DNA-binding and protein dimerization domains of PBX1 replaces the TCF3 helix-loop-helix DNA-binding motif in TCF3-PBX1 fusion. The remaining transcriptional activating domains of TCF3 leads to constitutive nuclear localization and transformation of PBX1 into an oncogenic transcriptional factor [5][1][2]

Genetic Diagnostic Testing Methods

  • Conventional chromosome analysis with FISH confirmation
  • RT-PCR
  • DNA or RNA based NGS analysis [2]

Familial Forms

Put your text here (Instructions: Include associated hereditary conditions/syndromes that cause this entity or are caused by this entity.)

Additional Information

  • Another translocation involving the TCF3 gene is t(17;19) which results in the fusion of HLF at 17q22 with TCF3. This variant translocation has been reported in approximately 1% of pediatric B-ALL patients and is associated with a poor prognosis. [1][4]
  • A karyotypically identical t(1;19) has been observed in a subset of B-ALL cases, especially in hyperdiploid B-ALL. This translocation does not involve TCF3 or PBX1. Therefore, a FISH confirmation is often necessary to determine the nature of t(1;19). [1][2]

Links

TCF3

PBX1

Put your links here (use "Link" icon at top of page)

References

(use the "Cite" icon at the top of the page) (Instructions: Add each reference into the text above by clicking on where you want to insert the reference, selecting the “Cite” icon at the top of the page, and using the “Automatic” tab option to search such as by PMID to select the reference to insert. The reference list in this section will be automatically generated and sorted. If a PMID is not available, such as for a book, please use the “Cite” icon, select “Manual” and then “Basic Form”, and include the entire reference.)

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds): WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition). IARC: Lyon 2017
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Akkari, Yassmine M. N.; et al. (05 2020). "Evidence-based review of genomic aberrations in B-lymphoblastic leukemia/lymphoma: Report from the cancer genomics consortium working group for lymphoblastic leukemia". Cancer Genetics. 243: 52–72. doi:10.1016/j.cancergen.2020.03.001. ISSN 2210-7762. PMID 32302940 Check |pmid= value (help). Check date values in: |date= (help)
  3. Jeha, Sima; et al. (2021-07). "Clinical significance of novel subtypes of acute lymphoblastic leukemia in the context of minimal residual disease-directed therapy". Blood Cancer Discovery. 2 (4): 326–337. doi:10.1158/2643-3230.bcd-20-0229. ISSN 2643-3249. PMC 8265990 Check |pmc= value (help). PMID 34250504 Check |pmid= value (help). Check date values in: |date= (help)
  4. 4.0 4.1 4.2 Meloni-Ehrig A., (2013). The principles of clinical cytogenetics. 3rd edition. Steven L. Gersen and Martha B. Keagle , Editors. Springer. DOI 10.1007/978-1-4419-1688-4. p327-329.
  5. Diakos, Christofer; et al. (2014). "Direct and indirect targets of the E2A-PBX1 leukemia-specific fusion protein". PloS One. 9 (2): e87602. doi:10.1371/journal.pone.0087602. ISSN 1932-6203. PMC 3913655. PMID 24503810.

Notes

*Primary authors will typically be those that initially create and complete the content of a page. If a subsequent user modifies the content and feels the effort put forth is of high enough significance to warrant listing in the authorship section, please contact the CCGA coordinators (contact information provided on the homepage). Additional global feedback or concerns are also welcome.








*Citation of this Page: “B lymphoblastic leukaemia/lymphoma with TCF3::PBX1 fusion”. Compendium of Cancer Genome Aberrations (CCGA), Cancer Genomics Consortium (CGC), updated 12/4/2023, https://ccga.io/index.php/HAEM5:B_lymphoblastic_leukaemia/lymphoma_with_TCF3::PBX1_fusion.