Expression of CD56 defines a distinct subgroup in childhood T‐ALL with inferior outcome. Results of the ALL‐BFM 2000 trial. (20th July 2018)

• Record Type: Journal Article
• Authors: Fuhrmann, Stephan; Schabath, Richard; Möricke, Anja; Zimmermann, Martin; Kunz, Joachim B.; Kulozik, Andreas E.; Ludwig, Wolf‐Dieter; Schrappe, Martin; Karawajew, Leonid; Ratei, Richard
• Is Part Of: British journal of haematology. Volume 183:Number 1(2018)
• Page Start: 96
• Page End: 103
• Publication Date: 2018-07-20
• Subjects: childhood leukaemia -- immunophenotyping -- ALL; Hematology -- Periodicals; Blood -- Diseases -- Periodicals; 616.15
• DOI: 10.1111/bjh.15503
• Languages: English
• ISSNs: 0007-1048

Abstract

Summary: This study reports the prognostic impact of the expression of the natural killer cell marker CD56 in a large series of risk‐adapted paediatric patients with T cell acute lymphoblastic leukaemia (T‐ALL; n = 493) treated within the ALL‐Berlin‐Frankfurt‐Münster (BFM) 2000 protocol. The immunophenotype was analysed centrally at diagnosis using flow cytometry and correlated with clinical parameters and outcome. CD56 expression was detected in 7·1% and early T‐cell precursor (ETP) phenotype in 6·7% of all T‐ALL patients. The percentage of ETP in the CD56+ T‐ALL cohort was 4‐fold higher than in the whole cohort. CD56+ T‐ALL frequently expressed the progenitor marker CD34 and myeloid antigens CD13 and CD33. The 5‐year event‐free survival (EFS) rates for the European Group for the Immunological classification of Leukaemias/World Health Organization subgroups and the ETP phenotype were not statistically different. By contrast, patients with CD56 expression had a significantly reduced EFS (60 ± 8%) and overall survival (60 ± 8%) at 5 years, with a hazard ratio of 2·46 ( P = 0·002) and 2·99 ( P < 0·001), respectively. Moreover, CD56 expression in combination with the minimal residual disease (MRD)‐based high risk assignment defined a population with a 'very‐high' risk probability of relapse in the ALL‐BFM 2000 trial. The CD56 marker has the potential to augment MRD‐based risk stratification and may serve as a molecular target for antibody‐based treatment strategies in childhood T‐ALL.