Comparison of characteristics and prognostic impact of FUS-ERG and AML1-MTG16 fusion genes in adult AML patients: A retrospective study from 1988 to 2022 with a medical database.

7042 Background: AML1-MTG16 and FUS-ERG are two rare fusion genes in acute myeloid leukemia (AML). Their clinical characteristics and factors influencing prognosis have been summarized in a cohort of pediatric patients, but no systematic review is approached in adult. Methods: We retrospectively analyzed the clinical data of adult AML patients with AML1-MTG16 or FUS-ERG fusion genes, who were reported on Mitelman Database, PubMed and China national knowledge infrastructure (CNKI) from 1988 to 2022 or have received treatment in the First Affiliated Hospital, Zhejiang University School of Medical, and compared them with patients with RUNX1-RUNX1T1, exploring their clinical features and prognosis. Results: 314 patients were totally included for analysis. In comparison of RUNX1-RUNX1T1 group (n = 209), FUS-ERG-positive patients (n = 108) significantly exhibited a younger onset age (34.5y vs. 41y), higher WBC count (16.7 ×10 9 /L vs. 10.4×10 9 /L), higher recurrence rate (61.8% vs. 30.4%), and a worse response to chemotherapy (complete remission rate: 71.6% vs. 91.8%), while patients with AML1-MTG16 (n = 24) presented primarily as the secondary AML (83.3%) with a significantly elder age (56y vs. 41y). The FUS-ERG patients had a worse median overall survival (OS) of 13 months (95%CI: 11.6-14.4, P < 0.01) and a worse median disease free survival (DFS) of 7.5 months (95%CI: 6.5-8.5, P < 0.05) than control group, which also occurred in those had AML1-MTG16 gene with a median OS of 18.5 months (95%CI: 12.4-24.6, P < 0.01) and a median DFS of 14 months (95%CI: 3.7-24.3, P = 0.10). As shown in the table below, CR after induction chemotherapy, hematopoietic stem cell transplantation (HSCT), trisomy, monosomy and age of patients were associated with the prognosis of FUS-ERG group. Unlike pediatric patients, the adult AML1-MTG16 patients did not perform a better outcome (OS: HR = 0.90, P = 0.83; DFS: HR = 0.54, P = 0.34) in contrast with FUS-ERG patients. Conclusions: The retrospective study summarized the clinical characteristics of AML1-MTG16 and FUS-ERG, identifying their distinctions on multiple aspects such as prior disease, recurrence rate, response to chemotherapy and cytogenetics. AML1-MTG16 exhibited extremely bad prognosis like FUS-ERG in adult population, which varied from the results in pediatric cohort. Several factors including age, CR after induction chemotherapy, HSCT, trisomy and monosomy were relevant to the prognosis of FUS-ERG. [Table: see text]