Brief Title
Comparison of Diagnostic Yield Among M-FISH, FISH Probe Panel and Conventional Cytogenetic Analysis in AML
Official Title
Comparison of Diagnostic Yield Among Multiplex Fluorescent in Situ Hybridization, Fluorescent in Situ Hybridization Probe Panel and Conventional Cytogenetic Studies in Acute Myeloid Leukemia
Brief Summary
Conventional cytogenetic studies have been the gold standard for more than five decades for
detecting genetic alterations that are greater than 10 Mb (mega base pairs) in size.
Conventional cytogenetic studies have paved the way in identifying specific chromosomal
aberrations associated with clinically and morphologically definitive subsets of
hematological neoplasms.
Fluorescence in situ hybridization (FISH) has become a reliable and rapid complementary test
in targeting critical genetic events associated with diagnostics and prognosis in
hematological neoplasms.
In the current health care environment, which increasingly focuses on value and efficiency,
it is critical for pathologists and clinicians to effectively navigate this environment and
judiciously incorporate these high-complexity and expensive techniques into routine patient
care. While conventional karyotyping provides a comprehensive view of the genome, FISH can
detect cryptic or submicroscopic genetic abnormalities and identify recurrent genetic
abnormalities in nondividing cells. As a consequence, it is commonly extrapolated that FISH
will improve the sensitivity of detecting all genetic abnormalities compared with
conventional karyotyping analysis. This assumption has then been translated in clinical
practice to having clinicians and pathologists routinely ordering both conventional
karyotyping and FISH studies in patients with hematological neoplasms. Depending on how
comprehensive the FISH panel is, the cost for this testing may be quite expensive, and its
additive value remains questionable.
It is common practice for laboratories to use FISH panels in conjunction with karyotyping
both in diagnostic specimens and during follow-up to monitor response to therapy.
Multiplex FISH (M-FISH) represents one of the most significant developments in molecular
cytogenetics of the past decade. In tumor and leukemia cytogenetics, two groups have been
targeted by M-FISH to identify cryptic chromosome rearrangements not detectable by
conventional cytogenetic studies: those with an apparently normal karyotype (suspected of
harboring small rearrangements not detectable by conventional cytogenetics) and those with a
complex aberrant karyotype (which are difficult to karyotype accurately due to the sheer
number of aberrations).
Detailed Description
Neoplastic hematology is at the forefront of personal¬ized medicine. The World Health
Organization (WHO) classification incorporates genetic data with microscopic,
immunophenotypic, and clini¬cal findings and categorizes hematologic neoplasms into
clinically and biologically distinct categories. This system guides diagnosis, prognosis and
therapeutic choices, which has become increasingly important with emerging targeted therapies
for lymphoma and leukemia. However, laboratory tests for hematologic neoplasms are of high
complexity and are generally quite costly.
The initial assessment of many hematologic neoplasms includes morphological, histological,
immunophenotypic (flow cytometric and/or immunohistochemical), and conventional cytogenetic
studies. Data obtained from cytogenetic analysis can be pathognomonic for specific leukemias
in the WHO classification (for example, acute myeloid leukemia (AML) with recurrent
cytogenetic abnormalities and chronic myelogenous leukemia (CML)) and are likely to assume a
greater role in defining specific categories in further classifications.
Conventional cytogenetic studies have been the gold standard for more than five decades for
detecting genetic alterations that are greater than 10 Mb (mega base pairs) in size. They
have paved the way in identifying specific chromosomal aberrations associated with clinically
and morphologically definitive subsets of hematological neoplasms.
Fluorescent in situ hybridization (FISH) has become a reliable and rapid complementary test
in targeting critical genetic events associated with diagnostics and prognosis in
hematological neoplasms. FISH has addressed the issues with conventional cytogenetic studies
by targeting interphase cells in addition to metaphases. It has become clear that FISH
studies may also be an integral component of the diagnostic evaluation, particularly where
the abnormality is "cryptic" i.e. not evident by conventional cytogenetic studies.
Although complementary FISH testing increases the overall detection of aberrations, its
benefit is not uniform across all types of hematological neoplasms. This is because FISH
probes are restricted to the detection of only specific abnormalities and genetic alterations
beyond the scope of the FISH probes would therefore be completely missed.
It is common practice for laboratories to use FISH probe panels in conjunction with
karyotyping both in diagnostic specimens and during follow-up to monitor response to therapy.
FISH is targeted toward specific abnormalities, and results can be evaluated in an automated
fashion on interphase nuclei, allowing for examination of more cells than conventional
cytogenetic studies. FISH has higher analytic and, in certain circumstances, higher clinical
sensitivity compared with conventional cytogenetic studies. The usage of FISH probe panels in
aiding diagnosis or in monitoring follow-up samples of hematologic neoplasms is critical.
The Eastern Collaborative Oncology Group (ECOG) compared conventional cytogenetic studies and
FISH in AML patients and found that a probe panel to detect monosomy 5/deletion 5q, monosomy
7/deletion 7q, trisomy 8, t(8;21), t(9;22), MLL rearrangements with various partners,
t(15;17), and inv(16)/t(16;16), had a concordance between 98% and 100%. On the other hand, He
et al study demonstrates the limited value of FISH testing in adult AML in the setting of an
adequate karyotyping study.
Despite of many significant technological advances made in recent years in the area of
clinical genetic testing, conventional cytogenetic studies and routine FISH studies remain
important laboratory testing tools available for evaluating hematologic neoplasms. Usually
these two testing methods complement each other and often FISH serves to clarify and better
define cytogenetic results. Therefore, there is a very strong expectation that cytogenetic
and FISH results should confirm each other in spite of cases that appear to be exceptions.
When conflicting results occur by these two testing methods on the same specimen, clinical
laboratories are challenged to offer explanations based on empirical data beyond simply
stating that it was or was not due to laboratory error.
Multiplex FISH (M-FISH) represents one of the most significant developments in molecular
cytogenetics of the past decade. In tumor and leukemia cytogenetics, two groups have been
targeted by M-FISH to identify cryptic chromosome rearrangements not detectable by
conventional cytogenetic studies: those with an apparently normal karyotype (suspected of
harboring small rearrangements not detectable by conventional cytogenetics) and those with a
complex aberrant karyotype (which are difficult to karyotype accurately due to the sheer
number of aberrations).
Zhang et al. used spectral karyotype (SKY) to re-evaluate the karyotypes of AML cases
reported as normal by G-banding. This resulted in the identification of one case of
t(11;19)(q23;p13), a subtle but recognized cytogenetic abnormality, and a minor clone
containing monosomy for chromosome 7 in another case. In a similar study, Mohr et al.
compared SKY to conventional karyotyping in patients with AML or MDS with normal karyotypes.
No abnormalities were identified.
With the lack of an evidence-based standardized algorithmic approach, misuse and
overutilization of laboratory tests are common and result in increased health care costs and
patient care complexity. In the current health care environment, which increasingly focuses
on value and efficiency, it is critical for pathologists and clinicians to incorporate
high-complexity and expensive techniques into routine patient care. While conventional
cytogenetic studies provide a comprehensive view of the genome, FISH probe panel can detect
cryptic or submicroscopic genetic abnormalities and identify recurrent genetic abnormalities
in nondividing cells. M-FISH can identify cryptic chromosome rearrangements that are not
detected by conventional cytogenetic studies. As a consequence, it is commonly extrapolated
that FISH will improve the sensitivity of detecting all genetic abnormalities compared with
conventional cytogenetic studies. This assumption has then been translated in clinical
practice to having clinicians and pathologists routinely ordering both conventional
cytogenetic studies and FISH studies in patients with hematological neoplasms. Depending on
how comprehensive the FISH probe panel is, the cost for this testing may be quite expensive,
and its additive value remains questionable.
Study Type
Observational
Primary Outcome
Evaluation of cytogenetic profile of AML patients in South Egypt
Secondary Outcome
Correlation between cytogenetic results and demographic, clinical and hematological data of AML patients
Condition
Acute Myeloid Leukemia
Intervention
Conventional Cytogenetics Studies
Study Arms / Comparison Groups
Acute Myeloid Leukemia (AML) group
Description: Patients who are diagnosed as Acute Myeloid Leukemia based on peripheral blood, bone marrow aspiration and immunophenotyping and fulfill WHO criteria for diagnosis. Fluorescent in Situ Hybridization (FISH) Panels for AML, Multiplex FISH (M-FISH) and Conventional Cytogenetics Studies will be performed for AML patients.
Publications
* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.
Recruitment Information
Recruitment Status
Diagnostic Test
Estimated Enrollment
120
Start Date
January 1, 2019
Completion Date
December 31, 2021
Primary Completion Date
December 31, 2021
Eligibility Criteria
Inclusion criteria:
1. Patients with newly diagnosed acute myeloid leukemia.
2. Age group: patients more than 18 years old.
Exclusion criteria:
1. Patients less than 18 years old.
2. Patients with other types of hematologic neoplasms.
3. Relapsed patients.
Gender
All
Ages
18 Years - N/A
Accepts Healthy Volunteers
No
Contacts
Eman Mosaad, MD, ,
Location Countries
Egypt
Location Countries
Egypt
Administrative Informations
NCT ID
NCT03719183
Organization ID
AssiutU-SECI-Cytogenetic 100
Responsible Party
Principal Investigator
Study Sponsor
Assiut University
Collaborators
South Egypt Cancer Institute
Study Sponsor
Eman Mosaad, MD, Study Director, South Egypt Cancer Institute
Verification Date
March 2022