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

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.