Clinical significance of trisomy 8 that emerges during therapy in chronic myeloid leukemia

An Update on the Management of Advanced Phase Chronic Myeloid Leukemia

PURPOSE OF REVIEW

While most patients with chronic myeloid leukemia (CML) present in a chronic phase and are expected to have a normal life expectancy, some patients present with or progress to a more aggressive accelerated phase (AP) or blast phase (BP) of CML. Herein, we discuss the diagnostic considerations of advanced phase CML and review its contemporary management.

RECENT FINDINGS

Later-generation, more potent BCR::ABL1 tyrosine kinase inhibitors (TKIs) such as ponatinib may result in superior outcomes in patients with advanced phase CML. For CML-BP, combination approaches directed against the blast immunophenotype appear superior to TKI monotherapy. The role of allogeneic stem cell transplantation is controversial in CML-AP but has consistently been shown to improve outcomes for patients with CML-BP. Advanced phase CML, particularly CML-BP, remains a poor risk subtype of CML. However, novel combination approaches using later-generation TKIs are being explored in clinical trials and may lead to improved outcomes.

The presence of additional cytogenetic aberrations in chronic myeloid leukemia cells at the time of diagnosis or their appearance on tyrosine kinase inhibitor therapy predicts the imatinib treatment failure

Currently used treatment of CML dramatically improved the prognosis of disease. However, additional chromosome aberrations (ACA/Ph+) are still one of the adverse prognostic factors.

OBJECTIVES

evaluation of the impact of ACA/Ph+ appearance during disease outcome on the response to treatment. THE STUDY GROUP: consisted of 203 patients. The median time of follow-up was 72 months. ACA/Ph+ was found in 53 patients.

RESULTS

patients were divided into four groups: standard risk, intermediate, high and very high risk. When ACA/Ph+ presence was documented at diagnosis time the optimal response was observed in 41.2%, 25%, and 0% of pts with intermediate, high and very high risk, respectively. If ACA/Ph+ were detected during imatinib treatment the optimal response was in 4.8% of patients. The risk of blastic transformation for patients with standard risk, intermediate, high and very high risk was 2.7%, 18.4%, 20% and 50%, respectively.

CONCLUSIONS

the presence of ACA/Ph+ at diagnosis time or their appearance on therapy seems to be clinically relevant not only in terms of the risk of blastic transformation but also in terms of the treatment failure. Gathering patients with various karyotypes and their responses to treatment would allow to set better guidelines and predictions.

Pathogenesis and management of accelerated and blast phases of chronic myeloid leukemia

The treatment of chronic myeloid leukemia (CML) with tyrosine kinase inhibitors (TKIs) has been a model for cancer therapy development. Though most patients with CML have a normal quality and duration of life with TKI therapy, some patients progress to accelerated phase (AP) and blast phase (BP), both of which have a relatively poor prognosis. The rates of progression have reduced significantly from over >20% in the pre-TKI era to <5% now, largely due to refinements in CML therapy and response monitoring. Significant insights have been gained into the mechanisms of disease transformation including the role of additional cytogenetic abnormalities, somatic mutations, and other genomic alterations present at diagnosis or evolving on therapy. This knowledge is helping to optimize TKI therapy, improve prognostication and inform the development of novel combination regimens in these patients. While patients with de novo CML-AP have outcomes almost similar to CML in chronic phase (CP), those transformed from previously treated CML-CP should receive second- or third- generation TKIs and be strongly considered for allogeneic stem cell transplantation (allo-SCT). Similarly, patients with transformed CML-BP have particularly dismal outcomes with a median survival usually less than one year. Combination regimens with a potent TKI such as ponatinib followed by allo-SCT can achieve long-term survival in some transformed BP patients. Regimens including venetoclax in myeloid BP or inotuzumab ozogamicin or blinatumomab in lymphoid BP might lead to deeper and longer responses, facilitating potentially curative allo-SCT for patients with CML-BP once CP is achieved. Newer agents and novel combination therapies are further expanding the therapeutic arsenal in advanced phase CML.

Cytogenetical and hematological analysis of chronic myelogenous leukemia patients with a novel case 52XX, t (1;9;22) (q23.3; q34; q11.2), +6, +8, i(9) (q10;q10), +18,+19,+21+der22 t(9;22)(q34;q11)

(9;22) (q34; q11) translocation is appear in above ninety percent of chronic myelogenous leukemia patients while variant/complex translocations were observed in almost 5% to 8% chronic myelogenous leukemia (CML) positive cases. Gleevec (Imatinib Mesylate) is the first choice breakpoint cluster region (BCR)/ABL targeted oral therapy that produced a complete response almost in 71% to 80% of patients affected with CML. A complete blood count (CBC) of 37 patients was done during diagnosis, however only 21 showed abnormal CBC values which were selected for the study. Karyotyping study using bone marrow samples was performed on 21 CML patients for the conformation of 9;22, however, fluorescence in situ hybridisation was performed for the detection of the BCR-ABL fusion gene of 15 patients. Out of 21, 17 patients showed Ph-positive (9;22) (q34; q11) translocation. Sixteen CML patients showed standard translocation however only CML patients showed a three-way variant/complex translocation with six additional chromosomes, 52XX, t(1;9;22) (q23.3;q34;q11),+6,+8, i(9)(q10;q10), +18,+19,+21 + der22 t(9;22)(q34;q11)). Here we report we report a novel case of six additional chromosomes with the three-way translocation of 52XX, t(1;9;22) (q23.3;q34;q11),+6,+8, i(9)(q10;q10), +18,+19,+21 + der22 t(9;22)(q34;q11) in blast phase.

Molecular, Cytogenetic, and Hematological Analysis of Chronic Myeloid Leukemia Patients and Discovery of Two Novel Translocations

Chronic myeloid leukemia (CML) is a disease of hematopoietic stem cells and is caused by the balanced translocations among the long arms of chromosomes 9 and 22, which are called the Philadelphia (Ph) chromosome. In this study, 131 CML patients were enrolled. Complete blood cell count was performed at the time of diagnosis for all the patients. Cytogenetic (karyotyping) examination using bone marrow samples was conducted on 76 CML patients for the confirmation of Ph-positive (9;22)(q34;q11) standard translocation, complex variant translocation, and additional chromosome abnormalities. FISH was performed on 38 patients for diagnostic purposes and on 39 patients for monitoring purposes. Twenty-two samples of CML patients were evaluated by reverse transcriptase PCR and real-time PCR for the patients who failed to respond against imatinib mesylate. In this study, 72 (54.96%) were males and 59 (45.03%) were females with a median age of 38.5 years. CBC values in the diagnosis process showed that 75 patients had high values of WBC being >100 × 103/μl, while 71 (58.01) patients exhibited reduced values of hemoglobin, i.e., <10.00 mg/dl, and high values of PLTs > 100 were observed in 40 (30.53%) patients. Cytogenetic results show that standard translocation was developed in 63 (82.89%), development of complex variant translocations in 4 (5.32%), additional chromosomal abnormalities (ACAs) in 3 (3.94%), and ACAs together with complex variant translocations in 1 (1.31%) patient. At the time of diagnosis, 61 (92.95%) patients were in the chronic phase, 4 (5.63%) were in the accelerated phase, and only 1 (1.40%) was in the blast crisis. Out of twenty-two patients, only 6 CML patients who were shifted from imatinib mesylate to nilotinib showed BCR-ABL-positive amplification. However, only 7 out of twenty-one patients exhibit BCR-ABL gene values ≥ 1 after three months of follow-up when analyzed by the quantitative real-time PCR. In conclusion, we found a novel five-way translocation 46XX,t(1;2;2;17;9;22)(p36.3,q21;q11.2,q21,q34,q11.2) and a novel four-way complex variant translocation 48XY,+8(8;17)(9;22),+der(22)(q11.2;q23)(q34;q11.2) in the accelerated phase.

From the archives of MD Anderson Cancer Center: Concurrent BCR-ABL1 and CRLF2 rearrangements in B-lymphoblast phase of chronic myeloid leukemia

The t(9;22)(q34;q11.2), also known as the Philadelphia (Ph) chromosome, results in BCR-ABL1 fusion residing on the derivative chromosome 22. This translocation is characteristic of chronic myeloid leukemia, but also can occur in a substantial subset of B acute lymphoblastic leukemia (B-ALL) cases. Ph-like B-ALL has a gene expression profile similar to that of BCR-ABL1 positive/Ph-positive B-ALL, but by definition Ph-like B-ALL does not have the sentinel BCR-ABL1 or the Ph chromosome. About half of Ph-like B-ALL cases carry CRLF2 rearrangements. Rare cases of de novo B-ALL with co-occurrence of BCR-ABL1 and CRLF2 rearrangements have been described. To our knowledge, this is the first report of concurrent BCR-ABL1 and CRLF2 rearrangements in blast phase of chronic myeloid leukemia. In this patient, CRLF2 rearrangement was acquired at the time of disease progression to B-lymphoblast phase of chronic myeloid leukemia. We also review the literature and discuss the distinct clinicopathologic, and genomic characteristics of CRLF2 rearranged B-ALL.

Rare monosomy 7 and deletion 7p at diagnosis of chronic myeloid leukemia in accelerated phase

Clonal cytogenic evolution with the development of additional chromosomal abnormalities (ACAs) in chronic myelogenous leukemia (CML) is a marker for disease progression and is known to impact therapy and survival. The presence of ACAs has been shown to affect the responses to tyrosine kinase inhibitors (TKI) in patients with newly diagnosed CML in accelerated phase (CML-AP). We report a rare case of a CML patient who presented in CML-AP and was found to have multiple ACAs including monosomy 7, deletion 7p, trisomy 8, and an extra Philadelphia chromosome (Ph) in separate Ph-positive cell line, respectively. Six months after combined chemotherapy with TKI, the patient achieved a major cytogenetic response with disappearance of monosomy 7/deletion 7p with no major molecular response.

Chronic myeloid leukemia with complex karyotypes: Prognosis and therapeutic approaches

OBJECTIVE AND BACKGROUND

Chronic myeloid leukemia (CML) is a neoplastic disease whose genetic and cytogenetic changes play important roles in prognosis and treatment strategies. Philadelphia (Ph) translocation t(9;22)(q34;q11) is a diagnostic and prognostic biomarker in CML.

METHODS

Pubmed and Google Scholar databases were searched for English language articles from 1975 to 2017 containing the terms CML; Additional chromosomal abnormalities; Philadelphia translocation; Prognosis; and Treatment.

DISCUSSION

Approximately 10-12% of CML patients exhibit additional chromosomal aberrations (ACAs) in chronic phase and blast crisis. ACAs emergence may cause different features in CML patients according to Ph pattern. For instance, deletion of chromosome 9 derivation is associated to patient's bad survival, whereas monosomy 7 develops myeloid dysplastic syndrome (MDS) or acute myeloid leukemia (AML) in CML patients with Ph-negative pattern. And ACAs in Ph-positive CML is considered as a failure in the management of CML with imatinib.

CONCLUSION

CML classification using different features such as Ph and ACAs can play a decisive role in the evaluation of treatment responses in patients, for example, CML patients with Ph negative and monosomy 7 develop MDS or CML patient -Y and extra copy of Ph have a good response to tyrosine kinase inhibitors, therefore, classifications according to Ph and ACAs play an important role in choosing better treatment protocols and therapeutic strategies. Karyotype analysis in CML patients with complex karyotype shows unrandom pattern so ACAs can be great clue in medical guidelines.

Myeloid neoplasms with concurrent BCR-ABL1 and CBFB rearrangements: A series of 10 cases of a clinically aggressive neoplasm

Chronic myeloid leukemia (CML) is defined by the presence of t(9;22)(q34;q11.2)/BCR-ABL1. Additional chromosomal abnormalities confer an adverse prognosis and are particularly common in the blast phase of CML (CML-BP). CBFB rearrangement, particularly CBFB-MYH11 fusion resulting from inv(16)(p13.1q22) or t(16;16)(p13.1;q22), is an acute myeloid leukemia (AML)-defining alteration that is associated with a favorable outcome. The co-occurrence of BCR-ABL1 and CBFB rearrangement is extremely rare, and the significance of this finding remains unclear. We identified 10 patients with myeloid neoplasms harboring BCR-ABL1 and CBFB rearrangement. The study group included six men and four women with a median age of 51 years (range, 20-71 years). The sequence of molecular alterations could be determined in nine cases: BCR-ABL1 preceded CBFB rearrangement in seven, CBFB rearrangement preceded BCR-ABL1 in one, and both alterations were discovered simultaneously in one patient. BCR-ABL1 encoded for p210 kD in all cases in which BCR-ABL1 preceded CBFB rearrangement; a p190 kD was identified in the other three cases. Two patients were treated with the FLAG-IDA regimen (fludarabine, cytarabine, idarubicin, and G-CSF) and tyrosine kinase inhibitors (TKI); seven with other cytarabine-based regimens and TKIs, and one with ponatinib alone. At last follow up (median, 16 months; range 2-85), 7 of 10 patients had died. The co-existence of BCR-ABL1 and CBFB rearrangement is associated with poor outcome and a clinical course similar to that of CML-BP, and unlike de novo AML with CBFB rearrangement, suggesting that high-intensity chemotherapy with TKI should be considered in these patients.