Thromboembolism in children with acute lymphoblastic leukaemia treated on Dana‐Farber Cancer Institute protocols: effect of age and risk stratification of disease

SummaryChildren with acute lymphoblastic leukaemia (ALL) are at increased risk for thromboembolism (TE). Identification of a susceptible population is crucial for effective thromboprophylaxis. However, the risk factors for ALL‐associated TE are unclear. Concomitant asparaginase (ASP) and steroid therapy has been shown to increase the incidence of TE. Dana‐Farber Cancer Institute (DFCI)‐ALL protocols use a combination of ASP and steroids during the postinduction intensification phase when high‐risk (HR) patients receive thrice the steroid‐dose given to standard‐risk (SR) patients. We studied prospectively assembled cohorts of children treated on two consecutive DFCI‐ALL protocols to define the risk factors for symptomatic TE. Ten (11%) of 91 patients developed symptomatic TE; eight (seven HR) during intensification. Seven (44%) of 16 older patients (≥10 years) compared with three of 75 (4%) younger patients developed TE (P < 0·0001). Nine of 35 (26%) HR and one of 56 (2%) SR patients developed TE (P = 0·0006). Gender, ALL‐immunophenotype, steroid‐type or ASP dosing schedule did not alter the risk but older age and HR‐disease were factors predisposing to TE associated with DFCI‐ALL protocols. Age‐related risk may partly reflect the effect of ALL‐risk stratification. Higher dose steroids combined with ASP may lead to an increased risk of TE in HR patients.

Thromboembolism in children with acute lymphoblastic leukaemia treated on Dana‐Farber Cancer Institute protocols: effect of age and risk stratification of disease Journal Articles