Osteonecrosis in children with acute lymphoblastic leukemia: A report from Children's Cancer Hospital Egypt (CCHE)

Background As survival rates for children with acute lymphoblastic leukemia (ALL) improve, awareness of treatment complications becomes important. Osteonecrosis (ON) is a serious disabling complication in treated ALL patients. The aim of the study was to define the frequency of ON identified by magnetic resonance imaging (MRI) and to study the risk factors for ON. Patients and methods Results The frequency of ON was evaluated retrospectively in 858 patients with ALL who were diagnosed at Children's Cancer Hospital of Egypt from January 2009 to December 2012. Patients were treated with St Jude Total Therapy Study XV. Of 858 patients evaluated, 665 were eligible for the study and 65 (9.7%) developed ON. The cumulative 5-year incidence of ON was 11.96% (SE, 0.131%). Of 154 patients aged 10 years and older, 40 (26%) developed ON. The mean age of patients with ON was 10.7 years. The prognostic factors with a significant relationship with ON were age 10 years and older (P = 0.0001) and intermediate-/high-risk group (P = 0.0001). However, gender did not have a significant relationship. At the onset of ON, the mean cumulative dexamethasone dose was 796 mg/m(2), and the mean total corticosteroid dose, calculated as prednisolone equivalence, was 6,431 mg/m(2). Out of 43 patients who developed ON while on corticosteroid therapy, 36 (84%) required dexamethasone dose modification and/or discontinuation. Conclusion The frequency of ON among the studied patients was 9.7%. Risk factors with a significant association with ON were older age and more intensive corticosteroid therapy.