Publication Only: Acute myeloid leukemia - Clinical
Childhood acute myeloid leukemia (AML) represents 20% of childhood acute leukemia. Despite major improvement in outcome, the prognostic is pejorative compared with childhood acute lymphoblastic leukemia.
We report the clinical features and treatment outcome of children de novo AML in southern Tunisia.
Our study is retrospective including Children (age ≤ 20 years) affected by de novo AML between January 2005 and June 2018 treated in the department of hematology of CHU Hedi Chaker Sfax. Diagnosis has been established according to FAB classification confirmed by flow cytometry. Secondary leukemia and FAB M3 were excluded. Induction chemotherapy associated cytarabine 200 mg/m2 for 7 days and daunorubicin 60 mg/m2 for 3 days or mitoxantrone 12 mg/m2 for 5 days. After induction, patients with an HLA-matched sibling donor underwent allogeneic Bone Marrow Transplantation (allo-BMT) in first complete remission (CR1). Patients without a matched sibling donor received in CR1 three or four courses of consolidation. We evaluated complete remission rate, overall survival (OS) and event-free survival (EFS). The Kaplan-Meier method was used to estimate OS and EFS.
We collected 52 cases of childhood AML, including 28 boys and 24 girls (sex ratio = 1.03). The median age at diagnosis was 12 years (1.5-20 years). The median initial white blood cell and hemoglobin level were 76 G/L (extreme 0.9 G/L - 900 G/L) and 6.5 g / dL respectively. The median count of platelet was 55000/mm3. Distribution according FAB classification was: 17% of AML0, 21% of AML1, 19% of AML2, 23% of AML4, 6%of AML5 and 2% of AML6, 6% of AML7 and 2% of AMLbipheno. Cytogenetic of bone marrow cells showed chromosomal abnormalities in 58% of cases, only 13 (25%) patients had favorable abnormalities. Thirty-one patients (60%) achieved complete response after one cure and 34 patients (65 %) after one or two courses of chemotherapy. Failure rate and toxic death were respectively 8% and 27%. Hematopoietic stem cell transplant was indicated in 24 (46%) patients but only 8 underwent the procedure. Nine patients (17.3%) relapsed within 8 months from diagnosis. The 5-year OS and EFS were 50% and 48% respectively.
Our study is characterized by frequent leucocytosis forms and FAB type M2. The CR rate and our EFS and OS rates observed in our series remain lower than in international trials. These can be explained by the frequency of refractory forms and the small number of bone marrow transplantation. Intensification chemotherapy of induction as well as consolidation therapy with allo-BMT can improve the outcome of our patients.