Philadelphia Chromosome-positive Acute Myeloid Leukemia With e1a3 BCR-ABL1 Fusion Transcript

The e1a3 BCR-ABL1 fusion transcript in Philadelphia chromosome-positive acute lymphoblastic leukaemia: a case report

ABSTRACTThe Philadelphia (Ph) chromosome results from the formation of breakpoint cluster region (BCR)-Abelson 1 (ABL1) fusion gene (BCR-ABL1). The most common type of adult acute lymphoblastic leukaemia (ALL) is Ph chromosome-positive (Ph+); Ph+ ALL has an incidence of 25%∼30%. Several types of BCR-ABL1 fusion transcripts have been reported, including e1a2, e13a2 and e14a2. In addition, some rare BCR-ABL1 transcripts, such as e1a3, have been reported in chronic myeloid leukaemia. However, until now, the presence of e1a3 BCR-ABL1 fusion transcripts has only been reported in a few cases of ALL. In this study, a rare e1a3 BCR-ABL1 fusion transcript was found in a patient diagnosed with Ph+ ALL. However, the patient also suffered from severe agranulocytosis with pulmonary infection and died after being transferred to the intensive care unit before the significance of the presence of e1a3 BCR-ABL1 fusion transcript could be determined. In conclusion, e1a3 BCR-ABL1 fusion transcripts related to Ph+ ALL cases need to be better identified, and appropriate treatment strategies must be designed for such cases.

Aleukemic Extramedullary Blast Crisis as an Initial Presentation of Chronic Myeloid Leukemia with E1A3 BCR-ABL1 Fusion Transcript

Right neck swelling and pain occurred in a 49-year-old man. A Blood count showed a slight increase in platelet count without leukemoid reaction. After a biopsy of the cervical mass and bone marrow aspiration, a diagnosis of extramedullary blast crisis (EBC) of chronic myeloid leukemia (CML) was made. Fluorescence in situ hybridization (FISH) analysis showed a BCR-ABL1 fusion signal, but results of real-time polymerase chain reaction (RT-PCR) for major and minor BCR-ABL1 transcripts were negative. We identified a rare e1a3 BCR-ABL1 fusion transcript. Administration of dasatinib resulted in disappearance of the extramedullary tumor. This is the first reported case of CML-EBC with e1a3 transcript. An aleukemic extramedullary tumor can be the initial presentation of CML.

Long-Term Outcome of Philadelphia Chromosome Positive Leukemia From Eastern Indian Subcontinent: An Experience in the Era of Tyrosine Kinase Inhibitor (TKI) Therapy

INTRODUCTION

Philadelphia chromosome (Ph) marks a group of leukemia with almost all cases of chronic myeloid leukemia (CML), a subset of acute lymphoid leukemia (ALL) and rare cases of acute myeloid leukemia (AML). In the era of precision medicine, such cases are successfully managed with tyrosine kinase inhibitor (TKI) drugs. This study examined the features and long-term outcome of Ph+ve cases from a tertiary cancer care center from Eastern Indian subcontinent.

MATERIALS AND METHODS

Reviewing retrospective case-records registered between 2005 and 2015, cases of CML and ALL were documented under Ph+ve category; while no instance of Ph+ve AML was found.

RESULTS

In CML cohort, adult and juvenile incidences were 95.2% and 4.8% respectively; in ALL cohort, the same was found for 66.67% and 33.33% cases. Among the CML cases, 10-year overall survival (OS) and progression-free survival (PFS) were significantly affected upon the phase of disease at time of detection. Furthermore, both OS and PFS significantly dropped whenever non-TKI-based treatment was applied prior to TKI-commencement. Long-term (10-year) sensitivity to 1st generation TKI, imatinib, was noted 88.51% and 83.33% for adult and juvenile CML cohorts, respectively. For Ph+ ALL cohort, the OS was benefitted upon combinatorial TKI and chemotherapy. However, large fractions of affected individual from CML as well as ALL cohorts were found to discontinue follow-up.

CONCLUSION

Together with differences in outcome on the basis of drug-use from onset, age (juvenile versus adult) and stage at diagnosis, our analyses bring forward the real-world scenario of Ph+ve leukemia managed with precision medicine.