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Objective Overexpression of ABCG2 and CD200 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 FLT3-negative/ NPM1-mutated cytogenetically normal ( CN) AML. Methods We analyzed 65 adult AML patients with CBF+ (n=16) or FLT3−/ NPM1+ CN (n=49), evaluating clinical and biological factors associated with complete remission attainment, leukemia-free survival ( LFS) and overall survival ( OS). Results ABCG2 was expressed in 36 (55%) cases, and CD200 was positive in 33 (51%) cases, six at high levels. Both ABCG2 and CD200 positivity have a negative impact on relapse risk: 3-year LFS was 51% vs 82% in ABCG2+ cases ( RR 3.3), 49% vs 82% in CD200+ patients ( RR=4.4), and 25% in CD200− high cases ( RR=17.1). ABCG2 and CD200 affected also OS with 3-year OS of 39% in ABCG2+ (compared to 71% in ABCG2−; RR=2.6) and CD200+ (compared to 68% in CD200−; RR=2.5) patients. Conclusions Our data confirm a negative impact of ABCG2 and CD200 overexpression also in AML patients considered at favorable risk according to ELN cytogenetic/molecular classification. [ABSTRACT FROM AUTHOR]

BCL-2 overexpression has been associated with resistance to chemotherapy and reduced survival in acute myeloid leukemia (AML), but few data are available in elderly patients, a subset accounting for majority of AML cases and with dismal prognosis. We retrospectively analyzed 113 AML patients aged ≥65 years treated with 3 + 7 chemotherapy (n = 51) or hypomethylating agents (HMAs) (n = 62), evaluating the role of BCL-2 expression on complete remission (CR) and overall survival (OS). BCL-2 was expressed in 81 patients (72%), more frequently in those with unfavorable cytogenetic-molecular risk. CR was achieved in 34.5% cases, without differences according to BCL-2 expression or induction therapy. In the whole population 1-year OS was 39%, similar in BCL-2+ and BCL-2- cases. In BCL-2 positive patients OS was superior with HMAs (56% vs. 25% with 3 + 7; p = 0.02), while no advantage for HMA was found in BCL-2 negative cases (36% vs. 27% for 3 + 7). Therapy with HMAs was the only factor associated with longer OS in BCL-2+ AML by multivariable analysis. Use of HMAs, possibly in combination with BCL-2 inhibitors, appears to be particularly appealing in BCL2+ AML, where it is associated with superior survival. [ABSTRACT FROM AUTHOR]

Overexpression of CD200, a trans-membrane protein belonging to the immunoglobulin superfamily, has been associated with poor prognosis in patients with acute myeloid leukemia (AML). As few data are available in the subset of cytogenetically-normal (CN) AML, we retrospectively evaluated the correlations between CD200 expression and response to therapy in a series of 139 adults with CN-AML. CD200 was expressed in 67/139 (48%) cases; 18 of them (28%) expressed CD200 at high intensity. No differences in CD200 expression rate were observed according to age, WBC count, type of leukemia, FLT3 or NMP1 mutation, and CD56 expression. A higher incidence of CD200 expression was observed in CD34+ cases (P < 0.0001) and in BCL2+ patients (P = 0.04). Complete remission (CR) was evaluable achieved in 98 patients (70%): 56/71 (79%) in CD200- and 47/67 (63%) in CD200+ patients (P = 0.03), with a lower CR rate in patients with high CD200 intensity (9/18, 50%). CD200 expression had a negative impact on long-term outcome. CD200 expression, per se, did not impact on disease-free survival (DFS), but cases with high CD200 expression had a lower 3-year DFS compared to CD200-negative and low-expressing ones (0% vs 65% vs 68%, P = 0.019). Three-year overall survival (OS) was 51% in CD200- and 27% in CD200+ patients (P = 0.01), with a significant difference among cases with low or high CD200 expression (35% vs 0%, P = 0.001). CD200 high expression defined a group with very poor DFS and OS also among the 37 FLT3-/NPM1+: 3-year DFS and OS were 88% and 60% in CD200-, 50% and 32% in CD200 low and 0% and 0% in CD200 high patients, respectively (P = 0.01 for DFS and P = 0.05 for OS). Our data suggest a negative impact of CD200 expression in CN-AML, with a further worsening in high-expressing cases, also in the subset of FLT3-/NPM1+ patients. [ABSTRACT FROM AUTHOR]