Impact of clinical factors on outcome of leukemia patients with TLS-ERG fusion gene.

We report the clinical features and outcome of 22 TLS-ERG+  leukemia patients (20 AML and 2 B-ALL). TLS-ERG was tightly associated with extramedullary disease (EMD), complex chromosome abnormalities, and high risk gene mutations including IKZF1, WT1, TET2, NOTCH2, and PHF6. The 6-month leukemia free survival (LFS) with and without EMD was 75% and 83.3% (p = .017). 11/20 AML patients received allogeneic hematopoietic stem cell transplantation (HCT). The 1-year overall survival (OS) in non-HCT and HCT group was 62.5% and 90% (p = .026), but the 6-month LFS in non-HCT and HCT group was 55.6% and 100% (p = .192). The 6-month LFS of patients with complete remission (CR) before HCT versus those with no response (NR) was 67.5% and 0, respectively (p = .034). In conclusion, the leukemia burden before HCT and EMD had negative impact on the outcome of TLS-ERG patients; HCT could prolong OS, but could not overcome the poor prognostic impact of TLS-ERG.