Clinical features and outcomes of fusion gene defined adult Ph-negative B-cell precursor acute lymphoblastic leukemia patients: a single institutional report

Abstract

More clinical studies are needed to clarify the risk stratification by the integration of all fusion genes in adult B-cell precursor acute lymphoblastic leukemia (BCP-ALL). A total of 320 consecutive adult Ph-negative BCP-ALL patients who had been tested classical fusions (KMT2A rearrangement and TCF3-PBX1) at diagnosis were further retrospectively screened novel fusion genes (Ph-like, ZNF384 and MEF2D fusions) by multiplex real-time quantitative PCR (RQ-PCR). Classical fusions were identified in 12.5% of patients, while 4.4%, 17.2% and 3.8% of patients were identified Ph-like, ZNF384 and MEF2D fusions, respectively. 1-course CR rate, relapse-free survival (RFS) and overall survival (OS) rates tended to show or showed statistically significant differences among fusion-defined subgroups (P = 0.084,  0.001 and 0.0093, respectively). Based on individual outcomes, patients with KMT2A rearrangement, TCF3-PBX1, Ph-like, and MEF2D fusions were classified into fusion-defined high-risk group (n = 66, 20.6%). High-risk group had significantly lower 3-year RFS and 3-year OS rates than standard-risk group (P 0.001 and = 0.0022), and was an independent adverse prognostic factor for RFS in the entire cohort (P 0.001). In conclusion, the spectrum of fusion genes in the current Chinese cohort was distinct from that in reports from western countries. Detection of fusion genes improved risk stratification in adult Ph-negative BCP-ALL patients.