Genetic analysis of dasatinib-treated chronic myeloid leukemia rapidly developing into acute myeloid leukemia with monosomy 7 in Philadelphia-negative cells

Acute myeloid leukemia with t(11;19)(q23;p13.1) in a patient with a gastrointestinal stromal tumor undergoing imatinib therapy: A case report

BACKGROUND

Acute myeloid leukemia (AML) harboring 11q23 translocations is classified as therapy-related AML in patients who have undergone prior treatment with cytotoxic agents. There have been only a few reports of AML that subsequently developed during imatinib mesylate (IM) treatment for gastrointestinal stromal tumors (GISTs).

CASE SUMMARY

A 63-year-old woman was diagnosed with a hepatic GIST recurrence in April 2012; she was administered IM 400 mg/d. In November 2015, she developed dyspnea with pancytopenia while IM treatment was continued for 42 mo. A chromosome study using a bone marrow sample showed a 46, XX karyotype with t(11;19)(q23;p13.1) in 22 of 26 analyzed metaphase cells. Fluorescence in situ hybridization using the locus-specific indicator (11q23) gene break-apart probe showed positive rearrangement in 82% of interphase cells. Reverse-transcription polymerase chain reactions subsequently confirmed the KMT2A/ELL transcript. She achieved complete response with incomplete neutrophil recovery with two decitabine treatment cycles. After the third cycle of decitabine, the disease relapsed, and she refused further treatment. She died of hemorrhagic stroke 5 mo after diagnosis. To the best of our knowledge, this is the first report of AML with KMT2A gene rearrangements in a patient with a GIST receiving IM treatment.

CONCLUSION

Physicians should consider the potential risks of developing hematologic malignancies, including therapy-related AML, in patients with GISTs receiving IM treatment.

Case Report of acute myeloid leukemia with "WT1, ATRX, CEBPA, CSMD1, IKZF1, and LRP1B mutation and translocation between chromosome 1 and 19" developing from Philadelphia-negative chronic myeloid leukemia after TKI therapy

RATIONALE

The success of tyrosine kinase inhibitor (TKI) therapy has greatly prolonged the survival time of patients with chronic myeloid leukemia (CML), harboring the characteristic Philadelphia (Ph) chromosome. However, a fraction of patients, achieving complete cytogenetic response after TKI therapy, develop a myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) with additional clonal chromosomal abnormalities in Philadelphia-negative cells (CCA/Ph-).

PATIENT CONCERNS

A 56-year-old woman with AML, developing from Philadelphia-negative CML after TKI therapy. She showed 6 kinds of somatic variants-CEBPA, ATRX, WT1, CSMD1, IKZF1, and LRP1B mutation after diagnosed as AML.

DIAGNOSIS

The patient was diagnosed with chronic phase CML that developed to AML after achieving durable complete cytogenetic response (CCR) and major molecular response (MMR).

INTERVENTIONS

The patient was treated with TKI therapy at the period of CML. When diagnosed with AML, she received induction chemotherapy regimens, consolidation therapy, and allogeneic hematopoietic stem cell transplantation subsequently.

OUTCOMES

The patient has been CCR and MMR for nearly 4 years, and has achieved complete remission after intervention related to AML. She is now preparing for allogeneic hematopoietic stem cell transplantation.

LESSONS

These rare occurrences highlight the importance of exploring the relevant pathogenesis of AML developing from CML after TKI therapy. In addition to monitoring molecular changes in the course of CML, cytogenetic analysis, or next-generation sequencing of CML patients should be performed.

Clinical implications of clonal chromosomal abnormalities in Philadelphia negative cells in CML patients after treated with tyrosine kinase inhibitors

Emergence of clonal chromosomal abnormalities in Philadelphia chromosome-negative (CCA/Ph-) cells in chronic myeloid leukemia (CML) patients during the treatment with tyrosine kinase inhibitors (TKIs) is an interesting phenomenon. Although previous studies revealed some potential impact of CCA/Ph- on CML patients' outcome, clinical significance of CCA/Ph- in CML patients remains to be further elucidated. We retrospectively reviewed the patients with CML evaluated at Genoptix Medical Laboratory in Carlsbad, California from 2005 to 2015. Twenty-four CML patients with CCA/Ph- cells were identified. These include 18 patients with single chromosomal abnormality, 4 patients with double chromosomal abnormalities, and two patients with complex cytogenetic abnormalities. In addition to trisomy 8 and monosomy 7, we identified that 20q- was also a common abnormality in CCA/Ph- cells. Most of the patients with CCA/Ph- cells demonstrated no significant dysplasia or increased blasts with two exceptions: one patient with persistent 7q- exhibiting mild dysmegakaryopoiesis, suggestive of an early evolving myelodysplastic syndrome, and another patient with complex cytogenetic abnormalities who developed acute myeloid leukemia after gained MLL amplification. One patient with complex cytogenetic abnormalities showed optimal response to TKI treatment, no overt dysplasia, and no disease progression during almost 4-years of follow-up. More interestingly, FISH tests could identify more cases with double chromosomal abnormalities and these cases showed suboptimal responses to TKI treatments. Our observation indicates that 20q- was also a common abnormality in CCA/Ph- cells, further FISH tests revealed additional CCA/Ph-, and the majority of CML patients with two or more chromosomal abnormalities in Ph- cells showed inferior response to TKI treatments. The results of our study suggest that CML cases with CCA/Ph- may represent a group of patients with heterogeneous genetic alterations.

[Philadelphia chromosome-negative myeloid neoplasms in patients with Philadelphia chromosome-positive chronic myeloid leukemia during tyrosine kinase inhibtor-therapy]

Objective: To compare the clinical features between the 2 cohorts developing myelodysplastic syndrome or acute myeIogenous Ieukemia in Philadelphia chromosome-negative cells (Ph(-) MDS/AML) and maintaining disease stable in the patients with Philadelphia chromosome-positive chronic myeloid Ieukemia (Ph(+) CML) who had clonal chromosomal abnormalities in Philadelphia chromosome-negative metaphases (CCA/Ph(-)) during tyrosine kinase inhibtor (TKI) - therapy. Methods: We retrospectively analyzed Ph(+) CML patients who developed CCA/Ph(-) during TKI-therapy from May 2001 to December 2017. Results: Data of CCA/Ph(-) 63 patients, including 7 progressing to Ph(-) MDS/AML and 56 remaining disease stable were collected. Compared with those with stable disease, patients with Ph(-)MDS/AML had lower hemoglobin (P=0.007) and platelet (P=0.006) counts, and higher proportion of peripheral blasts (P<0.001) when the first time CCA/Ph(-) was detected, and more mosonomy 7 abnormality (5/7, 71.4%) when MDS or AML was diagnosed; meanwhile, trisomy 8 (32/56, 57.1%) was more common in those with stable disease. Outcome of the patients with Ph(-) MDS/AML were poor. However, most of those with CCA/Ph(-) and stable disease had optimal response on TKI-therapy. Conclusions: A few patients with Ph(+) CML developed CCA/Ph(-) during TKI-therapy, most of them had stable disease, but very few patients developed Ph(-) MDS/AML with more common occurrence of monosomy 7 or unknown cytopenia. Our data suggested the significance of monitoring of peripheral blood smear, bone marrow morphology and cytogenetic analysis once monosomy 7 or unknown cytopenia occurred.

Clonal chromosomal aberrations in Philadelphia negative cells such as monosomy 7 and trisomy 8 may persist for years with no impact on the long term outcome in patients with chronic myeloid leukemia

The appearance of clonal chromosomal aberrations in Philadelphia negative cells (CCA/Ph-) during the treatment of chronic myeloid leukemia (CML) was recently confirmed. Importance of these findings has not been clearly defined. We present data on the time of appearance, persistence, size of the CCA/Ph- clone in terms of drugs used and hematological, cytogenetic and molecular response rates. The focus was on the peripheral blood cytopenias and myelodysplastic changes in the bone marrow microscopic evaluation. In 5 out of 155 (3,2%) CML patients, the persistent presence (up to nine years) of CCA/Ph- was found (monosomy 7 and trisomy 8 in unrelated clones in two patients treated with tyrosine kinase inhibitors; trisomy 8 in two patients on imatinib; trisomy 21 in one patient on interferon alfa treatment). Aberrations were present in median 24% Ph- cells in 3-15 subsequent analyses at different cytogenetic and molecular response time points. No evident myelodysplastic changes nor transformation to MDS/AML occurred in patients with CCA/Ph-. All the patients achieved major molecular response (MMR). It seems that CCA/Ph- presence does not affect the long term outcome in patients with chronic myeloid leukemia. Further complex monitoring of the CML patients with CCA/Ph- is still needed.

Transient monosomy 7 in a chronic myelogenous leukemia patient during nilotinib therapy: a case report

Tyrosine kinase inhibitor treated chronic myelogenous leukemia patients with monosomy 7 arising in Philadelphia chromosome negative (Ph−) cells tend to evolve into MDS/AML. However, monosomy 7 in Ph− cells can be a transient finding, and it is not an absolute indication of the emergence of a new myeloid malignancy.

Multiparameter flow cytometry is instrumental to distinguish myelodysplastic syndromes from non-neoplastic cytopenias

Mandatory for the diagnosis of myelodysplastic syndromes (MDS) is the presence of dysplasia in >10% of cells within one or more cell lineages or presence of >15% ring sideroblasts or presence of MDS-associated cytogenetic (CG) abnormalities. Discrimination between neo-plastic and non-neoplastic causes of cytopenias can be challenging when dysplastic features by cytomorphology (CM) are minimal and CG abnormalities are absent or non-discriminating from other myeloid neoplastic disorders. This study evaluated a standard diagnostic approach in 379 patients with unexplained cytopenias and highlights the additional value of flow cytometry (FC) in patients with indeterminate CM and CG. CM reached no clear-cut diagnosis in 44% of the patients. Here, CG was able to identify two additional patients with MDS; other CG results did not reveal abnormalities or were not contributory. Based on the FC results, patients without a diagnosis by CM and CG were categorized 'no MDS-related features' (65%), 'limited number of MDS-related changes' (24%), and 'consistent with MDS' (11%). Patients were followed over time in an attempt to establish or confirm a diagnosis (median follow-up 391 d, range 20-1764). The specificity (true negative) of MDS-FC analysis calculated after follow-up was 95%. FC can aid as a valuable tool to exclude MDS when CM and additional CG are not conclusive in patients with cytopenia.

-7/7q- syndrome in myeloid-lineage hematopoietic malignancies: attempts to understand this complex disease entity

The recurrence of chromosomal abnormalities in a specific subtype of cancer strongly suggests that dysregulated gene expression in the corresponding region has a critical role in disease pathogenesis. -7/7q-, defined as the entire loss of chromosome 7 and partial deletion of its long arm, is among the most frequently observed chromosomal aberrations in myeloid-lineage hematopoietic malignancies such as myelodysplastic syndrome and acute myeloid leukemia, particularly in patients treated with cytotoxic agents and/or irradiation. Tremendous efforts have been made to clarify the molecular mechanisms underlying the disease development, and several possible candidate genes have been cloned. However, the study is still underway, and the entire nature of this syndrome is not completely understood. In this review, we focus on the attempts to identify commonly deleted regions in patients with -7/7q-; isolate the candidate genes responsible for disease development, cooperative genes and the factors affecting disease prognosis; and determine effective and potent therapeutic approaches. We also refer to the possibility that the accumulation of multiple gene haploinsufficiency, rather than the loss of a single tumor suppressor gene, may contribute to the development of diseases with large chromosomal deletions such as -7/7q-.

Myelodysplastic syndrome (MDS)-associated cytogenetic abnormalities in pediatric chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is very rare in the pediatric population. We report the case of a 2-year-old female with CML and concurrent myelodysplastic syndrome (MDS) associated cytogenetic abnormalities. The co-existence of t(9;22) and chromosomal deletions that are associated with MDS poses a unique diagnostic challenge. Given the reported association of t(9;22) and genomic instability, we hypothesize that the chromosomal deletions represent clonal evolution of the CML.

Factors influencing a second myeloid malignancy in patients with Philadelphia-negative -7 or del(7q) clones during tyrosine kinase inhibitor therapy for chronic myeloid leukemia

The detection of Philadelphia-negative (Ph(neg)) cells with non-random karyotypic abnormalities after tyrosine kinase inhibitor (TKI) therapy of chronic myeloid leukaemia (CML) can be associated with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). To our knowledge, however, there have been no studies on variables influencing the risk of MDS/AML in patients with specific Ph(neg) karyotypes. We systematically examined studies reporting -7 or del(7q) within Ph(neg) cells in TKI-treated CML patients, and abstracted clinical and cytogenetic data from individual reports into a standardized format for further analysis. Of 53 patients, 43 had Ph(neg) -7 clones [as the sole abnormality (-7(sole)) in 29, or with other clones (-7(dual)) in 14], and del(7q) was present in 10. A total of 16/51 evaluable patients, all with -7, transformed to MDS/AML. Transformation was more frequent (15/16 patients) within 6 months of Ph(neg) -7 detection rather than subsequently (P < 0.0001). At first detection after TKI therapy, Ph(neg) abnormal clones comprised ≥50% of Ph(neg) cells in a greater proportion of patients with -7 than del(7q) (P = 0.035). Upon comparing -7(sole) and -7(dual), the latter was likely to be transient (P = 0.004), and AML was frequently observed with persistent -7 clones (P = 0.03). By logistic regression analysis (n = 36), clone size (P = 0.017), time-to-detection longer than 15 months (P = 0.02), and CML response (P = 0.085) were associated with MDS/AML. Validation of these novel associations in registry-based studies will help develop predictive criteria that define the MDS/AML risk in individual patients.

Myelodysplastic syndrome with Ph negative monosomy 7 chromosome following transient bone marrow dysplasia during imatinib treatment for chronic myeloid leukemia

We describe a 60-year-old Japanese patient with chronic myeloid leukemia (CML) who developed myelodysplastic syndrome (MDS) with Ph negative monosomy 7 chromosome following transient bone marrow dysplasia during imatinib treatment. Most cases that developed chromosomal abnormality in Ph negative cells during imatinib therapy were reported to have less clinical implications, while rare cases developed MDS/AML. The present case suggested that metaphase karyotype analysis and bone marrow examination should be performed for the long term follow-up under imatinib treatment in cases showing cytopenia. The results also suggested that monosomy 7 in Ph negative cells may be an indicator of a poor prognosis.