OBJECTIVETo investigate factors that affect survival and prognosis of acute myeloid leukemia (AML)-M(4).

METHODSSeventy AML-M(4) patients were divided into three groups, neither eosinophilia nor inv(16)\[Eos(-)\], eosinophilia with inv (16)\[Eos(+) inv(16)(+)\], and eosinophilia with no inv(16)\[Eos(+) inv(16)(-)\]. Clinical features, immunophenotype, chromosome karyotype, overall survival (OS) and relapse-free survival (RFS) were analyzed.

RESULTSThe total complete remssion (CR) rate was 85.7%, CR rate after the first course of induction therapy was 71.4%. The median OS was 20 (1.2 - 162.4) months, and median RFS 78.0 (1.2 - 129.5) months. The 3 and 5 year OS rates were 42% and 42%, and 3 and 5 year RFS rates were 59% and 54%, respectively. The CR rate, CR after the first course of induction therapy and the median OS for the Eos(-) group were 76.9%, 61.5% and 11.2 (1.2 - 162.4) months; for the Eos(+) group were 96.8%, 89.6% and did not reach; for the Eos(+)inv16(+) group were 100%, 94.4% and did not reach; and for the Eos(+) inv(16)(-) group were 91.7%,69.2% and 14.3 months respectively. The statistical assay showed significant difference between Eos(+)inv(16)(-) and Eos(+)inv(16)(+) groups in OS. The Eos(+) patients present with early onset and low count of platelets.

CONCLUSIONEosinophilia emerged as a favorable prognostic factor, and the concomitant presence of both eosinophilia and inv(16) is associated with a significantly favorlable prognosis.