RESUMO
Overall survival of patients classified according to the European LeukemiaNet 2020 classification. Chronic phase (CP), accelerated phase (AP), blast crisis (BC), low risk (LR), intermediate risk (IR), high risk (HR).
Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Crise Blástica/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêuticoRESUMO
There is an emerging body of evidence that patients with chronic myeloid leukaemia (CML) may carry not only breakpoint cluster region-Abelson murine leukaemia viral oncogene homologue 1 (BCR-ABL1) kinase domain mutations (BCR-ABL1 KD mutations), but also mutations in other genes. Their occurrence is highest during progression or at failure, but their impact at diagnosis is unclear. In the present study, we prospectively screened for mutations in 18 myeloid neoplasm-associated genes and BCR-ABL1 KD in the following populations: bulk leucocytes, CD34+ CD38+ progenitors and CD34+ CD38- stem cells, at diagnosis and early follow-up. In our cohort of chronic phase CML patients, nine of 49 patients harboured somatic mutations in the following genes: six ASXL1 mutations, one SETBP1, one TP53, one JAK2, but no BCR-ABL1 KD mutations. In seven of the nine patients, mutations were detected in multiple hierarchical populations including bulk leucocytes at diagnosis. The mutation dynamics reflected the BCR-ABL1 transcript decline induced by treatment in eight of the nine cases, suggesting that mutations were acquired in the Philadelphia chromosome (Ph)-positive clone. In one patient, the JAK2 V617F mutation correlated with a concomitant Ph-negative myeloproliferative neoplasm and persisted despite a 5-log reduction of the BCR-ABL1 transcript. Only two of the nine patients with mutations failed first-line therapy. No correlation was found between the mutation status and survival or response outcomes.
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Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Seguimentos , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Mutação , Prognóstico , Estudos ProspectivosRESUMO
The occurrence of mutations in the BCR-ABL1 kinase domain (KD) can lead to treatment resistance in chronic myeloid leukaemia patients. Nowadays, next-generation sequencing (NGS) is an alternative method for the detection of kinase domain mutations, compared to routinely used Sanger sequencing, providing a higher sensitivity of mutation detection. However, in the protocols established so far multiple rounds of amplification limit reliable mutation detection to approximately 5% variant allele frequency. Here, we present a simplified, one-round amplification NGS protocol for the Illumina platform, which offers a robust early detection of BCR-ABL1 KD mutations with a reliable detection limit of 3% variant allele frequency.
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Proteínas de Fusão bcr-abl/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Voluntários Saudáveis , Humanos , MutaçãoRESUMO
ABSTRACT: Advancements in genomics are transforming the clinical management of chronic myeloid leukemia (CML) toward precision medicine. The impact of somatic mutations on treatment outcomes is still under debate. We studied the association of somatic mutations in epigenetic modifier genes and activated signaling/myeloid transcription factors (AS/MTFs) with disease progression and treatment failure in patients with CML after tyrosine kinase inhibitor (TKI) therapy. A total of 394 CML samples were sequenced, including 254 samples collected at initial diagnosis and 140 samples taken during follow-up. Single-molecule molecular inversion probe (smMIP)-based next-generation sequencing (NGS) was conducted targeting recurrently mutated loci in 40 genes, with a limit of detection of 0.2%. Seventy mutations were detected in 57 diagnostic samples (22.4%), whereas 64 mutations were detected in 39 of the follow-up samples (27.9%). Carrying any mutation at initial diagnosis was associated with worse outcomes after TKI therapy, particularly in AS/MTF genes. Patients having these mutations at initial diagnosis and treated with imatinib showed higher risks of treatment failure (hazard ratio, 2.53; 95% confidence interval, 1.13-5.66; P = .0239). The adverse prognostic impact of the mutations was not clear for patients treated with second-generation TKIs. The multivariate analysis affirmed that mutations in AS/MTF genes independently serve as adverse prognostic factors for molecular response, failure-free survival, and progression risk. Additionally, there was an observable nonsignificant trend indicating a heightened risk of progression to advanced disease and worse overall survival. In conclusion, mutations in the AS/MTF genes using smMIP-based NGS can help identify patients with a potential risk of both treatment failure and progression and may help upfront TKI selection.
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Leucemia Mielogênica Crônica BCR-ABL Positiva , Mutação , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Masculino , Pessoa de Meia-Idade , Feminino , Adulto , Idoso , Transdução de Sinais , Inibidores de Proteínas Quinases/uso terapêutico , Prognóstico , Fatores de Transcrição/genética , Resultado do Tratamento , Sequenciamento de Nucleotídeos em Larga Escala , Adulto Jovem , Idoso de 80 Anos ou mais , Progressão da DoençaRESUMO
Several studies have reported that chronic myeloid leukaemia (CML) patients expressing e14a2 BCR::ABL1 have a faster molecular response to therapy compared to patients expressing e13a2. To explore the reason for this difference we undertook a detailed technical comparison of the commonly used Europe Against Cancer (EAC) BCR::ABL1 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assay in European Treatment and Outcome Study (EUTOS) reference laboratories (n = 10). We found the amplification ratio of the e13a2 amplicon was 38% greater than e14a2 (p = 0.015), and the amplification efficiency was 2% greater (P = 0.17). This subtle difference led to measurable transcript-type dependent variation in estimates of residual disease which could be corrected by (i) taking the qPCR amplification efficiency into account, (ii) using alternative RT-qPCR approaches or (iii) droplet digital PCR (ddPCR), a technique which is relatively insensitive to differences in amplification kinetics. In CML patients, higher levels of BCR::ABL1/GUSB were identified at diagnosis for patients expressing e13a2 (n = 67) compared to e14a2 (n = 78) when analysed by RT-qPCR (P = 0.0005) but not ddPCR (P = 0.5). These data indicate that widely used RT-qPCR assays result in subtly different estimates of disease depending on BCR::ABL1 transcript type; these differences are small but may need to be considered for optimal patient management.
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Proteínas de Fusão bcr-abl , Leucemia Mielogênica Crônica BCR-ABL Positiva , Proteínas de Fusão bcr-abl/genética , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Neoplasia Residual/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Standardized monitoring of BCR::ABL1 mRNA levels is essential for the management of chronic myeloid leukemia (CML) patients. From 2016 to 2021 the European Treatment and Outcome Study for CML (EUTOS) explored the use of secondary, lyophilized cell-based BCR::ABL1 reference panels traceable to the World Health Organization primary reference material to standardize and validate local laboratory tests. Panels were used to assign and validate conversion factors (CFs) to the International Scale and assess the ability of laboratories to assess deep molecular response (DMR). The study also explored aspects of internal quality control. The percentage of EUTOS reference laboratories (n = 50) with CFs validated as optimal or satisfactory increased from 67.5% to 97.6% and 36.4% to 91.7% for ABL1 and GUSB, respectively, during the study period and 98% of laboratories were able to detect MR4.5 in most samples. Laboratories with unvalidated CFs had a higher coefficient of variation for BCR::ABL1IS and some laboratories had a limit of blank greater than zero which could affect the accurate reporting of DMR. Our study indicates that secondary reference panels can be used effectively to obtain and validate CFs in a manner equivalent to sample exchange and can also be used to monitor additional aspects of quality assurance.
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Leucemia Mielogênica Crônica BCR-ABL Positiva , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Padrões de Referência , Resultado do TratamentoRESUMO
This work investigated patient-specific genomic BCR-ABL1 fusions as markers of measurable residual disease (MRD) in chronic myeloid leukaemia, with a focus on relevance to treatment-free remission (TFR) after achievement of deep molecular response (DMR) on tyrosine kinase inhibitor (TKI) therapy. DNA and mRNA BCR-ABL1 measurements by qPCR were compared in 2189 samples (129 patients) and by digital PCR in 1279 sample (62 patients). A high correlation was found at levels of disease above MR4, but there was a poor correlation for samples during DMR. A combination of DNA and RNA MRD measurements resulted in a better prediction of molecular relapse-free survival (MRFS) after TKI stop (n = 17) or scheduled interruption (n = 25). At 18 months after treatment cessation, patients with stopped or interrupted TKI therapy who were DNA negative/RNA negative during DMR maintenance (green group) had an MRFS of 80% and 100%, respectively, compared with those who were DNA positive/RNA negative (MRFS = 57% and 67%, respectively; yellow group) or DNA positive/RNA positive (MRFS = 20% for both cohorts; red group). Thus, we propose a "traffic light" stratification as a TFR predictor based on DNA and mRNA BCR-ABL1 measurements during DMR maintenance before TKI cessation.
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Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Reação em Cadeia da Polimerase/métodos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Adulto , Idoso , Feminino , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Masculino , Pessoa de Meia-Idade , Neoplasia Residual , RNA Mensageiro/análise , Indução de Remissão , Suspensão de TratamentoRESUMO
PURPOSE: The advent of tyrosine kinase inhibitor (TKI) therapies has revolutionized the treatment of chronic myeloid leukemia (CML). The European LeukemiaNet (ELN) recommends quantification of BCR-ABL1 transcripts by real-time quantitative PCR every 3 months during TKI treatment. Since a proportion of patients in deep molecular response (DMR: MR4, MR4.5, MR5) maintain remission after treatment stop, assessment of DMR is crucial. However, systematically collected molecular data, monitored with sensitive standardized assays, are not available outside clinical trials. METHODS: Data were collected on the standardized assessment of molecular response in the context of real-life practice. BCR-ABL1 transcript levels after > 2 years of TKI therapy were evaluated for DMR by local laboratories as well as standardized EUTOS laboratories. Since standardized molecular monitoring is a prerequisite for treatment discontinuation, central surveillance of the performance of the participating laboratories was carried out. RESULTS: Between 2014 and 2017, 3377 peripheral blood samples from 1117 CML patients were shipped to 11 standardized reference laboratories in six European countries. BCR-ABL1 transcript types were b3a2 (41.63%), b2a2 (29.99%), b2a2/b3a2 (3.58%) and atypical (0.54%). For 23.72% of the patients, the initial transcript type had not been reported. Response levels (EUTOS laboratory) were: no MMR, n = 197 (6.51%); MMR, n = 496 (16.40%); MR4, n = 685 (22.64%); MR4.5, n = 937 (30.98%); MR5, n = 710 (23.47%). With a Cohen's kappa coefficient of 0.708, a substantial agreement between EUTOS-certified and local laboratories was shown. CONCLUSIONS: Multicenter DMR assessment is feasible in the context of real-life clinical practice in Europe. Information on the BCR-ABL1 transcript type at diagnosis is crucial to accurately monitor patients' molecular response during or after TKI therapy.
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Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Inibidores de Proteínas Quinases/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Europa (Continente) , Humanos , Laboratórios/normas , Laboratórios/estatística & dados numéricos , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mieloide de Fase Crônica/sangue , Pessoa de Meia-Idade , Sistema de Registros , Adulto JovemAssuntos
Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Benzamidas , República Tcheca , Coleta de Dados , Avaliação de Medicamentos , Feminino , Humanos , Mesilato de Imatinib , Leucemia Mieloide de Fase Crônica/mortalidade , Masculino , Resultado do TratamentoRESUMO
Little is known about the function and phenotype of leukemic stem cells (LSCs) in chronic myeloid leukemia (CML) or about specific markers that discriminate LSCs from normal hematopoietic stem cells (HSCs). CD26 has recently been described as a specific marker of CML LSCs. In the current study, we investigated this marker in a cohort of 31 unselected CML patients. BCR/ABL1 positivity was analyzed in highly enriched stem cell fractions using fluorescence in situ hybridization (FISH) and reverse transcription PCR (RT-PCR). The proportion of CD26+ LSCs and CD26- HSCs varied considerably among the patients analyzed, and the percentage of CD26+ cells correlated with leukocyte count. The CD26 expression robustly discriminated LSCs from HSCs. This required a strict gating of the stem cell compartment. Thus, in patients with very low LSC or HSC numbers, only the highly sensitive RT-PCR method discriminated between clonal and non-clonal cells, while a robust FISH analysis required larger numbers of cells in both compartments. Finally, our data show that the numbers of CD26+ CML LSCs correlate with responses to treatment with BCR-ABL1 inhibitors.
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Dipeptidil Peptidase 4/biossíntese , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Células-Tronco Neoplásicas/imunologia , Dipeptidil Peptidase 4/imunologia , Humanos , Imunofenotipagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Células-Tronco Neoplásicas/patologia , PrognósticoAssuntos
Monitoramento de Medicamentos/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucócitos/citologia , Transportador 1 de Cátions Orgânicos/genética , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , RNA Mensageiro/análise , Benzamidas , Monitoramento de Medicamentos/normas , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Contagem de Leucócitos , Leucócitos Mononucleares , Neutrófilos , Piperazinas/farmacocinética , Pirimidinas/farmacocinética , RNA Neoplásico/análiseRESUMO
BACKGROUND AND OBJECTIVE: It has been shown that the occurrence of the BCR-ABL1 T315I mutation leads to a very poor therapeutic outcome in chronic myelogenous leukemia (CML) patients treated with tyrosine kinase inhibitors. Therefore, early detection of this mutation could potentially lead to early therapeutic intervention and a better prognosis with the ongoing treatment regimen. METHODS: The detection of BCR-ABL1 kinase domain (KD) mutations was performed by direct sequencing of peripheral blood (PB), total bone marrow (BM), and BM CD34+ cells from a reported CML patient. RESULTS: In this patient, the T315I mutation was detected in BM CD34+ cells 6 months prior to its emergence in PB, suggesting evolution and expansion of the T315I mutation clone, which most likely originated from more primitive CML cells. CONCLUSION: Our finding reflects the natural development of a T315I mutation within the hematopoietic system of the reported patient and indicates the importance of BCR-ABL1 mutation monitoring in more primitive cell populations. Considering the natural history of T315I development in this reported CML case, we hypothesize that BCR-ABL1 KD mutations may be pre-concentrated in more primitive CML cells, which subsequently expand into the PB. These findings may have future implications for the strategy used for detecting BCR-ABL1 mutations.
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Antígenos CD34/análise , Células da Medula Óssea/enzimologia , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteínas Tirosina Quinases/genética , Idoso , Antineoplásicos/uso terapêutico , Benzamidas , Células da Medula Óssea/citologia , Progressão da Doença , Humanos , Hidroxiureia/uso terapêutico , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Masculino , Mutação , Piperazinas/uso terapêutico , Pirimidinas/uso terapêuticoRESUMO
BACKGROUND AND OBJECTIVE: The availability of different tyrosine kinase inhibitors (TKIs) with distinct anti-leukemic potency enables optimization of current therapeutic regimens; however, some patients lose their therapy response and acquire TKI resistance. In this study, we describe a single-center experience of monitoring BCR-ABL1 kinase domain (KD) mutations and discuss the impact of treatment on mutation selection. METHODS: Chronic myelogenous leukemia (CML) patients treated with TKIs at the Department of Internal Medicine-Hematology and Oncology, Masaryk University and University Hospital Brno during 2003-2011 were included in this study. A total number of 100 patients who did not achieve an optimal therapy response or who lost their therapy response were screened for the presence of BCR-ABL1 KD mutations, using direct sequencing. RESULTS: Our data show that pretreatment with non-specific non-TKI drugs prior to TKI therapy does not preferentially select for initial BCR-ABL1 KD mutations, in contrast to first-line imatinib therapy, which shows a clear predominance of T315I or P-loop mutations compared with mutations located in other KD regions. In addition, the median time to detection of P-loop mutations was substantially shorter in patients treated with first-line imatinib than in those pretreated with non-TKI drugs. Furthermore, analysis of CML patients who had recurrent resistance to TKI therapy revealed possible therapy-driven selection of BCR-ABL1 KD mutations. Finally, we confirm the previously described poor prognosis of CML patients with mutations in the BCR-ABL1 KD, since 40.0% of our CML patients who harbored a BCR-ABL1 KD mutation died from CML while receiving TKI treatment. Moreover, among the patients who are still on treatment, 27.8% have already progressed. Our data also confirm the unique position of the T315I mutation with respect to its strong resistance to currently approved TKIs. CONCLUSION: On the basis of the 'real-life' data described in this study, it is possible that the therapy itself results in its failure and selects the most resistant mutations under the selective pressure of the applied therapy regimen in some CML patients who harbor BCR-ABL1 KD mutations.
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Antineoplásicos/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Adulto , Idoso , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas Tirosina Quinases/genéticaRESUMO
Acute promyelocytic leukemia (APL) with atypical breakpoints in the promyelocytic leukemia (PML) and retinoic acid receptor-alpha (RARA) genes represents a rare leukemic event, which occurs preferentially in patients with variant types of the PML/RARA fusion gene. Here we report on a patient with APL with a unique PML/RARA fusion transcript that harbors a short type of this fusion gene, exhibiting unexpected results of standard PCR diagnostics. The detected transcript originates from fusion of PML exon 4 and a truncated form of transcription variant 2 of the RARA gene, with an additional 9 bp insertion. According to our knowledge, this differs from all previously described fusion transcripts.
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Proteínas de Fusão Oncogênica/genética , Receptores do Ácido Retinoico/genética , Transcrição Gênica , Sequência de Bases , Eletroforese em Gel de Ágar , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Isoformas de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor alfa de Ácido RetinoicoRESUMO
OBJECTIVE: Of 140 chronic myeloid leukemia patients responding to imatinib with complete cytogenetic remission, 32 exhibited a plateau of BCR-ABL values at >or=0.1% level in a minimum of three subsequent samples (minimal duration, 6 - 9 months). Median follow-up of unchanged BCR-ABL transcript level was 12 months (range, 6 - 64). We tested this group of patient for BCR-ABL mutations to reveal resistance development and to evaluate the risk of disease progression. MATERIALS AND METHODS: Altogether, 134 samples of peripheral blood of these 32 patients were tested for mutation in BCR-ABL kinase domain. RESULTS: Mutation was detected by direct sequencing in 9 of 32 patients (28%). Loss of complete cytogenetic remission or 1 log rise of BCR-ABL was observed in five of nine patients at a median of 5 months (range, 4-17) since first detection of mutation. One patient with no mutation relapsed 12 months after the start of the BCR-ABL plateau. In 5 of 32 patients without mutation (16%), BCR-ABL level significantly decreased after the first plateau to levels that stayed unchanged for a median of 11 months (range, 7-28). CONCLUSION: We show here that the BCR-ABL constant levels >or=0.1% (BCR-ABL plateau) in imatinib-responding patients may indicate mutation analysis. This approach highly reduces the number of examinations for mutation in chronic myeloid leukemia responders and may present cost-effective alternative applicable in clinical practice.
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Antineoplásicos/uso terapêutico , Análise Citogenética , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Mutação , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , RNA Mensageiro/genética , Adulto , Idoso , Benzamidas , Feminino , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Reprodutibilidade dos TestesRESUMO
In recent years, several independent prognostic factors in cytogenetically normal acute myeloid leukemia (CN-AML) have been reported. Mutations or the expression levels of certain genes have been often used as molecular markers for prediction of a patient's outcome or for evaluation of treatment outcome. One of them, the gene encoding CCAAT/enhanced binding protein alpha (CEBPA), plays an important role in myeloid differentiation and, when mutated, confers a favorable prognosis for patients with CN-AML. Complete mutation screening of the CEBPA gene is therefore beneficial and requires fast, precise, and sensitive diagnostic tools. Thus, for routine diagnostics, we developed a screening method using high-resolution melt curve analysis prior to direct sequencing, where only positive samples (according to reference) are further sequenced. With this approach, all positive and negative patients were successfully distinguished, and the results obtained were in absolute concordance with the direct sequence analysis.