Expression of CD56 is an unfavorable prognostic factor for acute promyelocytic leukemia with higher initial white blood cell counts.
Bottom Line: Expression of CD56 was significantly associated with lower platelet count (P = 0.04), severe disseminated intravascular coagulation (P = 0.04), and coexpression of CD2 (P = 0.03), CD7 (P = 0.04), CD34 (P < 0.01) and/or human leukocyte antigen-DR (P < 0.01).Complete remission rate and overall survival were not different between the two groups.However, cumulative incidence of relapse and event-free survival (EFS) showed an inferior trend in CD56(+) APL (P = 0.08 and P = 0.08, respectively).
Affiliation: Department of Internal Medicine, School of Medicine, Hamamatsu University, Hamamatsu, Japan.Show MeSH
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Mentions: Overall survival was not different between the two groups (73.9% vs 79.2%, P = 0.52, at 9 years; Fig.1a), whereas EFS and CIR tended to be inferior in CD56+ APL (47.8% vs 64.8%, P = 0.08, and 39.1% vs 24.3%, P = 0.08, at 9 years, respectively; Figs2a,3a). In patients with initial WBC counts ≥3.0 × 109/L, EFS and CIR for 11 CD56+APL patients were significantly inferior to those for 87 CD56− APL patients (30.8% vs 63.6%, P = 0.008, and 53.8% vs 28.9%, P = 0.03, at 9 years, respectively; Figs2b,3b). In patients with initial WBC counts <3.0 × 109/L, EFS and CIR were not different between the two groups (P = 0.99 and P = 0.98, at 9 years, respectively). The OS in patients with initial WBC counts ≥3.0 × 109/L was similar between the two groups (61.5% vs 78.8%, P = 0.13, at 9 years; Fig.1b). Although the number was small, EFS and CIR for five CD56+ APL patients among those with initial WBC counts of ≥10 × 109/L were inferior to those for 41 CD56− APL patients (20.0% vs 60.9%, P = 0.03, and 60.0% vs 30.7%, P = 0.09, at 9 years, respectively). Cumulative incidence of extramedullary relapse tended to be more frequent in patients with CD56+ APL whose initial WBC counts were ≥3.0 × 109/L (9.3% vs 1.1%, at 9 years, P = 0.07). We also analyzed the influence of CD56 expression on clinical outcomes according to Sanz's relapse risk score.7 Both CIR and EFS in patients with CD56+ APL were inferior in the high risk group (60.0% vs 31.4%, P = 0.09 and 20.0% vs 62.5%, P = 0.02, respectively), but not in low and intermediate risk groups (P = 0.17 and P = 0.55, respectively).
Affiliation: Department of Internal Medicine, School of Medicine, Hamamatsu University, Hamamatsu, Japan.