Incidence and Risk Factors of Symptomatic Osteonecrosis in Children With Acute Lymphoblastic Leukemia—A Population‐Based Analysis of the Austrian ALL‐BFM Study Group

ABSTRACT Background Osteonecrosis is a clinically relevant therapy‐associated complication in pediatric acute lymphoblastic leukemia (ALL). Methods In a nationwide Austrian cohort of 1127 patients with newly diagnosed ALL treated on AIEOP‐BFM‐ALL 2000 and 2009 protocols, 73 patients developed symptomatic osteonecrosis. Results The corresponding 5‐year cumulative incidence was 7% ± 1%, while competing events such as relapse, death, and secondary malignancies were at 13% ± 1%. Median time to osteonecrosis was 1.64 years. Age at diagnosis was the dominant risk factor: the 5‐year incidence was 22% ± 3% in adolescent patients 10–18 versus 2% ± 0% in those 1–9 years‐old. Conclusions Age remained the only statistically independent predictor for osteonecrosis in multivariable analysis. Trial Registration : The authors have confirmed clinical trial registration is not needed for this submission