Clinical significance of cytogenetic findings at diagnosis and in remission in childhood and adult acute lymphoblastic leukemia: experience from India

Cytogenetics and Molecular Genetics in Pediatric Acute Lymphoblastic Leukemia (ALL) and Its Correlation with Induction Outcomes

Arathi SrinivasanAims  The aim was to study cytogenetics and molecular genetic profile in pediatric B-acute lymphoblastic leukemia (ALL) and correlate it with induction outcomes. Subjects and Methods  A retrospective study of cytogenetics and molecular genetics of 98 children with B-cell ALL from January 2013 to May 2018 was done. Cytogenetics and molecular genetics were done in the bone marrow using multiplex reverse transcription polymerase chain reaction and G-banded karyotyping, respectively. Minimal residual disease (MRD) assessment was done at the end of induction by flowcytometry. Results  Of the 98 children, 83 (84.6%) had evaluable cytogenetics, with 11 (13.25%) being abnormal karyotypes. Of the 11 abnormal karyotypes, seven children (8.4%) had hyperdiploidy, one had hypodiploidy, and three had miscellaneous findings. In molecular genetics, TEL-AML1 (ETV6/RUNX1)[t(12;21)] was the most common fusion gene abnormality (12.2% [12/98]), followed by E2A-PBX1 [t(1;19)] (5%), BCR/ABL1 [t(9;22)] (3%), and MLL-AF4 [t(4;11)] (1%). All the 98 children attained morphologic remission at the end of induction. All children with hyperdiploidy (7/7) attained remission and MRD negativity, but one expired during maintenance chemotherapy of disseminated tuberculosis. The child with hypodiploidy was MRD-positive. Three (25%) children with t (12;21) were MRD-positive. All children with Ph + ALL, t(1:19), and t(4;11) were MRD-negative. Fifty-two children had no detected abnormalities, six of whom had MRD positivity (11.5%). Conclusion  Cytogenetic and molecular genetic subgrouping prognosticates ALL outcomes. Although 25% of TEL-AML + children had MRD positivity, larger studies are required to validate the same. End-of-induction MRD outcomes did not correlate with chromosomal aberrations.

Study of the Chromosomal Abnormalities and Associated Complex Karyotypes in Hematological Cancer in the Population of West Bengal: A Prospective Observational Study

Introduction Chromosomal instability is an important feature of hematological cancer. The pathogenesis is complex and it involves genetic and epigenetic factors. As a genetic factor, chromosomal instability may play a key role in leukemogenesis. Accumulation of genetic alteration is mainly responsible for numerical and structural chromosomal rearrangement or clonal evaluation. But disease progression is often driven by chromosomal translocation, hyper- or hypodiploidy with structural abnormalities, and complex karyotypes.

Objective This research aimed to study the different types of chromosomal abnormalities in clinically suspected hematological cancer patients.

Materials and Methods Cytogenetic analysis was performed based on phytohemaglutinin stimulated peripheral blood lymphocyte cultures and bone marrow culture, without mitogen, of the respective patients of West Bengal from March 2016 to February 2018. All clinically suspected hematological cancer patients referred for karyotyping to the institutional genetics department have been included without any biasness of sex and age. Karyotypes were described according to the International System for Cytogenetic Nomenclature (ISCN 2005).

Results In the present study, 56 clinically suspected hematological cancer cases were observed and 41 cases of chromosomal rearrangement were found which clearly show chromosomal instability as the main driving force for hematological cancer transformation. Presence of variant Philadelphia chromosomes with classical translocation, mosaic complex karyotypes, variable numerical, and structural chromosomal abnormality, along with severe-to-moderate hypo- and hyperdiploidy, and presence of marker chromosomes were the main findings of this study.

Conclusion The result shows that the detection of chromosomal instability was important for preliminary diagnosis, treatment, prognosis, and further management. So the present study provided additional information about chromosomal instability in hematological cancer at Kolkata and adjoining regions.

Changing the frequency and spectra of chromosomal aberrations in Korean patients with acute leukemia in a tertiary care hospital

Background

Chromosomal analysis is essential for the diagnosis and risk stratification of all leukemia patients. Not surprisingly, racial differences in chromosomal aberrations (CA) in hematological malignancies could be found, and CA incidence in leukemia might change over time, possibly due to environmental and lifestyle changes. Thus, we compared the frequency and range of CA in patients with acute leukemia (AL) during two time periods (2006‒2009 vs. 2010‒2015) and compared them with other prior studies.

Methods

We enrolled 717 patients with AL during a six-year period (2010‒2015). We compared the results to those of our earlier study (2006‒2009) [1]. Conventional cytogenetics, a multiplex reverse transcriptase (RT)-PCR system, and fluorescence in situ hybridization were employed to assess bone marrow specimens or peripheral blood at the diagnostic stage in AL patients to detect CA.

Results

The incidence of CA changed in the leukemia subgroups during the two time periods. Notably, the most frequent CA of childhood acute myeloid leukemia (AML) was PML/RARA, and was followed by RUNX1/RUNX1T1 in the current study. In contrast, the most common CA was RUNX1/RUNX1T1 in a previous study [1] and was followed by PML/RARA. In this study, the most frequent CA of the mixed phenotype AL was BCR/ABL1, which was followed by KMT2A/MLLT3. In a previous report, [1] the most frequent CA was BCR/ABL1, which was followed by KMT2A/ELL.

Conclusion

The distribution of CA in Korean AL patients changed over time in a single institute. This change might be due to environmental and lifestyle changes.

Neurocognitive and Neuroanatomical Changes in Children with Acute Lymphoblastic Leukemia Treated with the Modified BFM-95 Protocol

Background: The use of cranial radiotherapy for central nervous system (CNS) prophylaxis in children with acute lymphoblastic leukemia (ALL) is debated owing to its effect on neurocognitive functioning, as only <30% of the patients present with low risk in India and majority of the patients with high risk have to be treated with cranial radiation therapy (CRT) to prevent relapse. Given the increasing number of ALL survivors in India, the effect of CRT on neurocognitive functioning in children with ALL needs to be studied. Methods: Children (n = 44) with ALL who received CRT, intrathecal methotrexate (IT-MTX), and high-dose methotrexate (HD-MTX) for CNS prophylaxis as part of the modified Berlin-Frankfurt-Munster 95 protocol were included. Neurocognitive assessments and magnetic resonance image were performed to assess neurocognitive functioning and neuroanatomical structures, respectively. Five assessments were performed during the induction, end of re-induction I and II, commencement of maintenance, and end of maintenance phases of the modified BFM-95 protocol. Neurocognitive data of children with ALL were compared with those of healthy children (n = 60) at the baseline and after the final assessment. Results: A significant deterioration was observed in the performance intelligence, visuospatial ability, processing speed, and verbal retention domains after the completion of CNS prophylaxis. Three children had white matter changes on magnetic resonance imaging and showed reduced functioning in performance intelligence quotient, working memory, visual immediate and delayed memory, processing speed, verbal retention, visuospatial ability, processing speed, attention, planning and fine motor skills, and verbal comprehension. Children with ALL had poorer neuropsychological functioning when compared with healthy children. Conclusion: CNS prophylactic therapy as part of the BFM-95 protocol had an adverse effect on the neuropsychological functioning of children with ALL, and the effect was more pronounced when CRT was added to the treatment.

Cytogenetic Profile of De Novo B lineage Acute Lymphoblastic Leukemia: Determination of Frequency, Distribution Pattern and Identification of Rare and Novel Chromosomal Aberrations in Indian Patients

BACKGROUND

Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an important role in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parameters are essential to physicians for planning cancer control interventions in different geographical regions.

MATERIALS AND METHODS

In this study, we present the overall frequency and distribution patterns of chromosomal aberrations in both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphase FISH and multiplex RT-PCR.

RESULTS

Among the 215 subjects, cytogenetic results were achieved in 172 (80%) patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3% hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complex karyotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also, FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes.

CONCLUSIONS

These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence of chromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reported series of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies are warranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities that may contribute to disease diagnosis and management.

Clinical features and induction outcome of childhood acute lymphoblastic leukemia in a lower/middle income population: A multi-institutional report from Pakistan

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood. Some evidence suggests differences in clinical and cytogenetic characteristics of ALL based on geographic and ethnic variations. However, data on ALL characteristics and early outcome of therapy from low/middle-income countries such as Pakistan are scanty.

PROCEDURE

A prospective, multi-institutional cohort study in Karachi enrolled 646 newly diagnosed children with ALL over 3 years. Standard forms were used to collect demographic, clinical, and laboratory data at presentation and at the end of induction.

RESULTS

Of the total, 66.1% (n = 427) were males. Median age was 6 (mean ± SE 6.87 ± 0.16; range 0.16-18) years. The most common clinical presentation was fever (88.7%). BPC-ALL was diagnosed in 78.5%, while 17.5% had T-ALL; 28.8% had a WBC >50 × 10(9) /L. With 316 patients karyotyped, hypodiploidy and hyperdiploidy were seen in 5.1% and 10.7%, respectively. Of those tested, ETV6-RUNX1 translocation was detected in 13.2%, while BCR-ABL1 translocation and MLL gene rearrangements were seen in 7.3% and 4.6%, respectively. The cumulative loss to follow up before and during induction was 12.8% (n = 83) and 11.5% (n = 74) died before or during this phase. Induction was successfully completed by only 75.6% (n = 489) of the entire cohort and 69.6% (n = 450) achieved remission.

CONCLUSION

These patients had ALL with higher risk features than that reported from developed countries. One quarter failed to complete induction chemotherapy. This suboptimal result requires further study and development of innovative interventions, particularly focusing on the causes and solutions for late referral, abandonment, and infections.

Banding cytogenetic analysis in pediatric patients with acute lymphoblastic leukemia (ALL) in a Brazilian population

BACKGROUND

Cytogenetic studies in Brazilian population about childhood acute lymphoblastic leukemia (ALL), the most common childhood malignancy, are scarce. Moreover, Brazilian race is very heterogeneous and is made by the confluence of people of several different origins, from the original Native Brazilians, with the influx of Portuguese colonizers, Black African slaves, and recent European, Arab and Japanese immigration. The purpose of this prospective, multicentric study was to assess the sociodemographic, clinic and cytogenetic characteristics of the children treated for ALL in the Northeast region of Brazil.

RESULTS

This study includes thirty patients between 4 months and 17 years old treated for ALL from January 1st, 2009 to November 30th, 2010. Cytogenetic analysis showed that in nineteen out of thirty patients (64%) presented some chromosome abnormalities, in which 53% corresponds to numerical abnormalities, 21% structural and numerical abnormalities, and 26% only structural changes. Moreover, seven patients presented complexes karyotype not yet described in the literature. Taken together these results show the importance of the cytogenetic analysis in ALL pediatric patients and illustrates that the studied population presented unexpected complexes karyotypes which were correlated to poor outcome.

CONCLUSION

The results demonstrate the importance of banding cytogenetics for ALL diagnosis despite the use of most modern techniques such as FISH and aCGH, and provide reliable insight into the ALL in Brazil.

Rare and recurrent chromosomal abnormalities and their clinical relevance in pediatric acute leukemia of south Indian population

BACKGROUND AND OBJECTIVES

This cytogenetic study detects a wide variety of common, rare and novel chromosomal abnormalities in patients with hematological disorders, providing valuable diagnostic and prognostic information.

MATERIALS AND METHODS

We addressed the utility of the cytogenetic technique in 50 patients of pediatric acute leukemia prospectively.

RESULTS

Successful cultures were found in 44 patients (88%) and abnormal karyotypes in 22 (44%). The common abnormalities like hyperdiploidy, del(6q), t(1;19)(q23;p13), t(4;11)(q22;q23), t(9;22)(q34;q11), rare t(2;7)(q23;p11) and t(4;12)(q21;p13) and a novel translocation t(7;9)(q22;q21) were observed in acute lymphoblastic leukemia. In acute myeloid leukemia, t(8;21)(q22;q22), del(16)(q22), t(15;17)(q22;q21) and t(9;11)(p22;q23) were commonly seen.

CONCLUSION

Chromosomal abnormalities of this small group of patients are compared with the relevant literature with respect to the incidence rate and prognosis.

Spectra of chromosomal aberrations in 325 leukemia patients and implications for the development of new molecular detection systems

This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and developed optimal profiles of leukemic fusion genes for multiplex RT-PCR. We prospectively analyzed blood and bone marrow specimens of patients with acute leukemia. Twenty types of chromosomal abnormalities were detected in 42% from all patients by commercially available multiplex RT-PCR for detecting 28 fusion genes and in 35% by cytogenetic analysis including FISH analysis. The most common cytogenetic aberrations in acute myeloid leukemia patients was PML/PARA, followed by AML1/MGT8 and MLL1, and in acute lymphoid leukemia patients was BCR/ABL, followed by TEL/AML1 and MLL1 gene rearrangement. Among the negative results for multiplex RT-PCR, clinically significant t(3;3)(q21;q26.2), t(8;14)(q24;q32) and i(17)(q10) were detected by conventional cytogenetics. The spectrum and frequency of chromosomal abnormalities in our leukemia patients are differed from previous studies, and may offer optimal profiles of leukemic fusion genes for the development of new molecular detection systems.

RUNX1 aberrations in ETV6/RUNX1-positive and ETV6/RUNX1-negative patients: its hemato-pathological and prognostic significance in a large cohort (619 cases) of ALL

A large-cohort study (619) of acute lymphoblastic leukemia (ALL) revealed an ETV6/RUNX1 (previously known as TEL/AML1) incidence of 18% in pediatric B-cell precussor ALL, indicating no geographical heterogeinity. Association of CD34-negative phenotype, peak incidence in the 3- to 7-year age group, and a comparatively low frequency of ETV6 homologue loss in ETV6/RUNX1-positive cases were distinct findings in this series. Additional genetic changes, such as ETV6 loss, extra RUNX1, ETV6/RUNX1 duplication, and MLL aberrations in the ETV6/RUNX1-positive group, supported the hypothesis of the ETV6/RUNX1 leukemogenic model that these secondary changes are necessary for leukemogenesis rather than progression of disease. This study disclosed RUNX1 alterations in the ETV6/RUNX1-negative group of BCP-ALL that encourages the investigation of RUNX1 at a large scale with longer follow-up, which will focus on the prognostic importance and the underlying biology of disease.

Cytogenetic profile of acute lymphocytic leukemia patients: report of a novel translocation t(4;13) (q21 x 3; q35) from an Indian population

Acute lymphocytic leukemia (ALL) is a malignant neoplasm characterized by clonal proliferation, decreased apoptosis and accumulation of immature lymphoid cells in the bone marrow as well as the peripheral blood. The aim of this study was to determine the overall cytogenetic profile of Indian ALL patients along with their frequency and distribution pattern. A total of 75 ALL subjects were included in the study. The major outcome of the work was identification of a novel translocation t(4;13) (q21 x 3;q35) that has not yet been reported. In addition, a few rare chromosomal aberrations such as t(4;16) (p16;q12 x 2) and t(7;10)(q36;q21 x 2) were also detected. Overall, of 75 cases, 67 (89 x 33%) were successfully karyotyped. Normal and abnormal karyotypes were seen in 38 (56 x 7%) and 29 (43 x 3%) cases respectively. Various other abnormalities were hyperdiploidy (20 x 68%), hypodiploidy (10 x 34%), t(8;14) (3 x 44%), t(9;22) (6 x 9%), t(4;16) (3 x 44%), t(7;10) (3 x 44%) and gain of chromosome 8, 13, 16, and 22 was seen in one case each (3 x 44%). Deletions in chromosome 5, 9 and 11 were found to be 3 x 44, 6 x 89 and 6 x 89% respectively, while complex and other aberrations were detected in 3 x 44 and 13 x 8% cases. Finally, we conclude that cytogenetic analysis has an important role in routine genetic diagnostic workup and management of ALL patients.

Cytogenetic Profile of Childhood Acute Lymphoblastic Leukemia in Oman

BACKGROUND

Chromosomal abnormalities have important diagnostic and prognostic significance in acute lymphoblastic leukemia (ALL). The purpose of this study was to define and classify the frequency and type of chromosomal abnormalities among newly diagnosed children with ALL and compare the results with those reported from other geographical regions of the world.

METHODS

Bone marrow chromosomal studies with GTG banding were performed in untreated ALL pediatric patients aged from 7 days to 14 years.

RESULTS

Among Omani children examined with ALL, 47 (81%) patients yielded results, with 26 (55.3%) showing an abnormal karyotype [10 (21.3%) pseudodiploid, 2 (4.3%) hypodiploid and 14 (29.7%) hyperdiploidy] and 21 (44.6%) had normal diploidy. Structural abnormalities were observed in 16 (34%), of which 11 (23.4%) cases were translocations, the most frequent being t(9;22) observed in three (6.4%) of our patients. Uncommon translocations such as t(9;15)(p11;q10), t(3;6)(p12;q11), t(1;6)(?31;?q23), t(1;19)(q12;q12), der(18)t(12;18)(q11;p11), and other structural aberrations add(2)(q22), add(6)(q16), add(18)(q22), add(14)(q32) along with deletions del(10)(q22), del(12)(p11), del(12)(p12), del(18)(q11) were also observed.

CONCLUSIONS

The study showed a good correlation and concordance between the ploidy distribution by cytogenetics and flow cytometry. The patterns of chromosomal anomalies in our patients showed some variations in the frequency of aberrations reported. It is therefore necessary that newer techniques like fluorescence in situ hybridization (FISH) along with reverse transcriptase polymerase chain reaction (RT-PCR) and spectral karyotyping will help us identify chromosomal aberrations not detected by conventional cytogenetic methods in the near future. To our knowledge, this is the first report from the Middle East of a cytogenetic study on childhood ALL.

Cytogenetics in childhood acute lymphoblastic leukemia in Taiwan: a single-institutional experience

The aim of the study was to define the frequency and types of acquired chromosomal aberrations in a group of Taiwanese children with ALL. The sample population consisted of 78 patients under 18 years of age with newly diagnosed ALL who underwent cytogenetic studies at diagnosis and had adequate metaphase chromosomes for analysis at the authors' hospital from 1993 to 2001. Metaphase chromosomes were banded using the conventional trypsin-Giemsa banding technique. Analysis of ploidy revealed 16 (20.5%) patients with normal diploidy, 28 (35.9%) with pseudodiploidy, 6 (7.7%) with hyperdiploidy (47-50), 19 (24.4%) with hyperdiploidy (> 50), and 9 (9.4%) hypodiploidy. Near-haploidy was not observed. Of the patients with abnormal karyotypes, recurrent structural abnormalities were determined in 31 (50%) cases, with the most frequent t(9;22). In conclusion, the frequency and type of acquired chromosomal aberrations found in these Taiwanese children with ALL are similar to those reported in the literature.

Antigen expression patterns reflecting genotype of acute leukemias

Multi-parameter flow cytometry, molecular genetics, and cytogenetic studies have all contributed to new classification of leukemia. In this review we discuss immunophenotypic characteristics of major genotypic leukemia categories. We describe immunophenotype of: B-lineage ALL with MLL rearrangements, TEL/AML1, BCR/ABL, E2A/PBX1 translocations, hyperdiploidy, and myc fusion genes; T-ALL with SCL gene aberrations and t(5;14) translocation; and AML with AML1/ETO, PML/RARalpha, OTT/MAL and CBFbeta/MYH11 translocations, trisomies 8 or 11 and aberrations of chromosomes 7 and 5. Whereas some genotypes associate with certain immunophenotypic features, others can present with variable immunophenotype. Single molecules (as NG2, CBFbeta/SMMHC and PML/RARalpha proteins) associated with or derived from specific translocations have been described. More often, complex immunophenotype patterns have been related to the genotype categories. Most known associations between immunophenotype and genotype have been defined empirically. Therefore, these associations should be validated in independent patient cohorts before they can be widely used for prescreening of leukemia. Progress in our knowledge on leukemia will show how the molecular-genetic changes modulate the immunophenotype as well as how the expressed protein molecules further modulate cell behavior.

Acute lymphoblastic leukemia incidence during socioeconomic transition: selective increase in children from 1 to 4 years

Pre-school acute lymphoblastic leukemia (ALL) peak is consistent in developed but not in developing countries and its magnitude apparently correlates with the socioeconomic status. A population-based study describing ALL incidence during socioeconomic transition has been lacking. Central European post-communist countries (with very low foreign migration and centralized statistics) offer reliable data for the period before and during major socioeconomic changes. Population-based data on Czech ALL patients younger than 18 years were taken from two independent Czech national registries partially overlapping in time (1980-1998, n = 1236 and 1991-1999, n = 570). During the 1980s and 1990s, ALL incidence among children 1-4 years increased 1.5 times (P = 0.01). This increase was more prominent in females than in males (slopes 0.13 and 0.09, P values 0.03 and >0.05, respectively). No significant change was observed in other age groups (0, 5-9, 10-14, 15-17 years or all others combined). We discuss possible underlying socioeconomic factors including infant care and breast-feeding, hygiene, birth order, industry and pollution. Moreover, we try to pinpoint the immunophenotypic/molecular-genetic subsets of ALL that might be socioeconomically affected. Selective increase of ALL in children 1-4 years old provides epidemiological evidence that etiology and/or trigger mechanisms are different for a considerable proportion of these children and that these mechanisms are exogenous.

Cytogenetics in acute lymphoblastic leukemia in Mexican children: an institutional experience

BACKGROUND

Cytogenetic studies in acute lymphoblastic leukemia (ALL) have identified numerical and structural chromosomal abnormalities related to the disease's pathophysiologic characteristics. These findings correlate with prognosis and response to treatment in ALL patients. The purpose of this study was to define the frequency of chromosomal abnormalities in a group of Mexican children with ALL and to compare these data with those reported in the literature.

METHODS

Bone marrow chromosome studies with GTG bands were performed in 150 pediatric patients with ALL who were naive to antileukemic treatment and aged from 5 months to 16 years; the majority was diagnosed as L1.

RESULTS

Among 131 patients, 30 (22.9%) karyotypes were normal and the remaining 101 (77.1%) had abnormal karyotypes with numerical and/or structural abnormalities. Among patients with numerical abnormalities, the most frequent karyotypes were hyperdiploidy with 51-65 chromosomes (30 patients) and hyperdiploidy with 47-50 chromosomes (18 patients). Among recurrent, non-random, and primary structural abnormalities, the most frequent was t(9;22), followed by t(1;19). Aberrations involving band 11q23 were not detected, and only one of two patients with L3 had the t(8;14). Of the secondary non-random abnormalities, dup(1q), del(6q), and i(7)(q10) were found.

CONCLUSIONS

The frequency and type of chromosomal abnormalities found was comparable to those reported in the literature with similar methodology and pediatric populations; however, the number of cases analyzed should be increased to create a database of Mexican children with ALL, and several patients require molecular analysis to identify chromosomal abnormalities not detected through conventional cytogenetic studies.