Expression of CD56 is an unfavorable prognostic factor for acute promyelocytic leukemia with higher initial white blood cell counts

• DOI: 10.1111/cas.12319
• Publication Date: 2013-11-11T03:32:47Z
• Authors: Takaaki Ono; Akihiro Takeshita; Yuji Kishimoto; Hitoshi Kiyoi; Masaya Okada; Takahiro Yamauchi; Nobuhiko Emi; Kentaro Horikawa; Mitsuhiro Matsuda; Katsuji Shinagawa; Fumihiko Monma; Shigeki Ohtake; Chiaki Nakaseko; Masatomo Takahashi; Yukihiko Kimura; Masako Iwanaga; Norio Asou; Tomoki Naoe
• Keywords: Adult; Male; 0301 basic medicine; Adolescent; Disease-Free Survival; Leukocyte Count; 03 medical and health sciences; 0302 clinical medicine; Leukemia, Promyelocytic, Acute; Antineoplastic Combined Chemotherapy Protocols; Humans; Prospective Studies; Aged; 2. Zero hunger; Platelet Count; Remission Induction; Cytarabine; Original Articles; Middle Aged; Prognosis; CD56 Antigen; 3. Good health; Treatment Outcome; Female; Neoplasm Recurrence, Local; Idarubicin

Expression of CD56 has recently been introduced as one of the adverse prognostic factors in acute promyelocytic leukemia (APL). However, the clinical significance of CD56 antigen in APL has not been well elucidated. We assessed the clinical significance of CD56 antigen in 239 APL patients prospectively treated with all‐trans retinoic acid and chemotherapy according to the Japan Adult Leukemia Study Group APL97 protocol. All patients were prospectively treated by the Japan Adult Leukemia Study Group APL97 protocol. The median follow‐up period was 8.5 years. Positive CD56 expression was found in 23 APL patients (9.6%). 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). Among patients with initial white blood cell counts of 3.0 × 109/L or more, EFS and cumulative incidence of relapse in CD56+ APL were significantly worse (30.8% vs 63.6%, P = 0.008, and 53.8% vs 28.9%, P = 0.03, respectively), and in multivariate analysis, CD56 expression was an unfavorable prognostic factor for EFS (P = 0.04). In conclusion, for APL with higher initial white blood cell counts, CD56 expression should be regarded as an unfavorable prognostic factor.