Clinical relevance of molecular aberrations in paediatric acute myeloid leukaemia at first relapse

• Published in: British journal of haematology 2014-09, Vol.166 (6), p.902-910
• Main Authors: Bachas, Costa, Schuurhuis, Gerrit Jan, Reinhardt, Dirk, Creutzig, Ursula, Kwidama, Zinia J., Zwaan, C. Michel, Heuvel‐Eibrink, Marry M., De Bont, Evelina S. J. M., Elitzur, Sarah, Rizzari, Carmelo, Haas, Valérie, Zimmermann, Martin, Cloos, Jacqueline, Kaspers, Gertjan J. L.
• Format: Article
• Language: English
• Subjects: acute myeloid leukaemia; Adolescent; Biological and medical sciences; Child; Child, Preschool; Disease-Free Survival; event free survival; Female; Genes, Neoplasm - genetics; Hematologic and hematopoietic diseases; Humans; Infant; Karyotype; Leukemia, Myeloid, Acute - genetics; Leukemia, Myeloid, Acute - therapy; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Male; Medical sciences; Mutation - genetics; mutation analysis; Neoplasm Proteins - genetics; overall survival; Recurrence; relapse; Risk Factors; Tumors
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1111/bjh.12989

Summary Outcome for relapsed paediatric acute myeloid leukaemia (AML) remains poor. Strong prognostic factors at first relapse are lacking, which hampers optimization of therapy. We assessed the frequency of molecular aberrations (FLT3, NRAS, KRAS, KIT, WT1 and NPM1 genes) at first relapse in a large set (n = 198) of relapsed non‐French‐American‐British M3, non‐Down syndrome AML patients that received similar relapse treatment. We correlated molecular aberrations with clinical and biological factors and studied their prognostic relevance. Hotspot mutations in the analysed genes were detected in 92 out of 198 patients (46·5%). In 72 of these 92 patients (78%), molecular aberrations were mutually exclusive for the currently analysed genes. FLT3‐internal tandem repeat (ITD) (18% of total group) mutations were most frequent, followed by NRAS (10·2%), KRAS (8%), WT1 (8%), KIT (8%), NPM1 (5%) and FLT3‐tyrosine kinase domain (3%) mutations. Presence of a WT1 aberration was an independent risk factor for second relapse (Hazard Ratio [HR] = 2·74, P = 0·013). In patients who achieved second complete remission (70·2%), WT1 and FLT3‐ITD aberrations were independent risk factors for poor overall survival (HR = 2·32, P = 0·038 and HR = 1·89, P = 0·045 respectively). These data show that molecular aberrations at first relapse are of prognostic relevance and potentially useful for risk group stratification of paediatric relapsed AML and for identification of patients eligible for personalized treatment.