ABCG2 and CD200 define patients at high risk of relapse in ELN favorable subgroup of AML

Objective Overexpression of ABCG 2 and CD 200 has been independently associated with poor outcome in acute myeloid leukemia ( AML ). However, no data are available on the role of these two factors in patients with core‐binding factor ( CBF )‐positive or FLT 3‐negative/ NPM 1‐mutated cytogenetically normal ( CN ) AML . Methods We analyzed 65 adult AML patients with CBF + (n=16) or FLT 3−/ NPM 1+ CN (n=49), evaluating clinical and biological factors associated with complete remission attainment, leukemia‐free survival ( LFS ) and overall survival ( OS ). Results ABCG 2 was expressed in 36 (55%) cases, and CD 200 was positive in 33 (51%) cases, six at high levels. Both ABCG 2 and CD 200 positivity have a negative impact on relapse risk: 3‐year LFS was 51% vs 82% in ABCG 2+ cases ( RR 3.3), 49% vs 82% in CD 200+ patients ( RR =4.4), and 25% in CD 200− high cases ( RR =17.1). ABCG 2 and CD 200 affected also OS with 3‐year OS of 39% in ABCG 2+ (compared to 71% in ABCG 2−; RR =2.6) and CD 200+ (compared to 68% in CD 200−; RR =2.5) patients. Conclusions Our data confirm a negative impact of ABCG 2 and CD 200 overexpression also in AML patients considered at favorable risk according to ELN cytogenetic/molecular classification.