The study of the impact of additional chromosomal aberrations and c-MYC and BCR::ABL1 genes amplification on CML patient’s characteristics: relation to haematological parameters and patient outcome

Abstract

BackgroundChronic myeloid leukaemia is characterised by genetic instability which results in additional cytogenetic aberrations that have been linked to progression to advanced phase. Genomic study linked amplified genes in the form of c-MYC and/or the rare BCR::ABL1 genes amplification to chronic myeloid leukaemia. The effect of these genes’ amplification on patients’ characteristics and disease progression still needs further study.This cross-sectional study aimed to investigate the frequency of additional chromosomal aberrations in addition to c-MYC and BCR::ABL1 genes amplification in chronic myeloid leukaemia patients and their impact on patient’s characteristics, disease progression, and level of remission. The study included cytogenetic analysis of 49 Philadelphia positive chronic myeloid leukaemia patients and investigation of c-MYC and BCR::ABL1 genes amplification by fluorescence in situ hybridization.ResultsPatients with additional chromosomal aberrations represented 36.7% and had significantly lower platelet count (P = 0.003) and higher blast count (P = 0.008). The acquisition of additional chromosomal aberrations was significantly higher in chronic myeloid leukaemia patients with advanced stages (P = 0.014). Follow-up of the patients for 6 months revealed significant higher frequency of additional chromosomal aberrations in patients with failure of remission (P < 0.0001). A highly significant association between cases with failure of molecular remission (P = 0.001) and co-existing additional chromosomal aberrations.Amplification of the c-MYC gene was detected in 6 cases. The cases with c-MYC amplification showed significantly higher peripheral blood and bone marrow blasts (P = 0.029 and P = 0.008, respectively) and significantly lower platelet count (P = 0.044). Amplification of c-MYC was significantly associated with additional chromosomal aberrations (P = 0.011). Molecular remission was not achieved in any of the instances with c-MYC amplification. A highly significant association between c-MYC amplification and poor patient outcome was detected (P = 0.002). BCR::ABL1 amplification was detected in three cases, and ABL amplification was detected in four cases. Patients with BCR::ABL1 amplification showed significantly higher blast count. BCR::ABL1 amplification was significantly associated with disease progression and failure of molecular remission (P = 0.002).ConclusionAdditional chromosomal aberrations, c-MYC amplification, and BCR:ABL1 amplification in chronic myeloid leukaemia stratify patients with disease progression, which may lead to better interventions and improved outcome in the future chronic myeloid leukaemia patients.