Myeloid/lymphoid neoplasms with FGFR1 rearrangement are a rare entity. We present a multicenter experience of 17 patients with FISH-confirmed FGFR1 rearrangement. The clinical presentation at diagnosis included myeloproliferative neoplasm (MPN) in 4 (24%) patients, acute leukemia (AL) in 7 (41%), and concomitant MPN with AL in 6 (35%). The two most frequently observed cytogenetic abnormalities were t(8;13)(p11.2;q12)(partner gene ZMYM2) and t(8;22)(p11.2; q11.2)(BCR). Seventy-eight percent of tested patients had a RUNX1 mutation, of whom all had AL. Overall response rate to frontline therapy was 69%, and 76% of patients subsequently received allogeneic stem cell transplant (ASCT). After a median follow-up of 11 months, median progression-free survival was 15 months and median overall survival was not reached. In conclusion, FGFR1-rearranged hematologic malignancies present with features of MPN and/or AL. FGFR1 and RUNX1 are therapeutic targets for ongoing and future clinical trials.
Keywords: FGFR1 rearrangement; Myeloproliferative neoplasm; RUNX1; acute leukemia.