Abstract
Venous thromboembolism (VTE) is a serious complication in paediatric oncology patients.
To identify the incidence, risk factors and recurrence rate of VTE in paediatric oncology
patients, an observational, retrospective cohort study of all consecutive children
(≤18 years) with malignancies, treated at the Emma Children's Hospital Academic Medical
Centre between January 1989 and December 2013, was done. A matched case–control study
in children with lymphomas was performed, to identify thrombotic risk factors. Cumulative
recurrence-free survival after first VTE was estimated by the Kaplan–Meier method.
Of the 2,183 children included (male: female = 1.4:1.0; median age, 6.6 years) with
cancer, 78 patients developed VTE (3.6%; 95% confidence interval [CI], 2.8–4.4). The
incidence increased from 0.8% (4/478, 95% CI, 0.0–1.6) between 1989 and 1993 to 10.4%
(44/423, 95% CI, 7.6–13.4) between 2009 and 2013. Independent risk factors for VTE
were age ≥ 12 years, acute lymphoblastic leukaemia (ALL) and lymphoma. The case–control
study in lymphoma patients showed a trend for increased VTE incidence in stage IV
lymphoma. Twelve (15.4%) patients developed recurrent thrombosis, 7 patients while
on therapeutic or prophylactic anticoagulation. The cumulative recurrence-free survival
after first VTE was 88.5, 87.1 and 80.6% after 1, 5 and 10 years, respectively. In
conclusion, we demonstrated an increasing incidence of VTE in children with malignancies,
with age ≥ 12 years, ALL and lymphoma as independent risk factors. The elevated recurrence
rate underlines the importance of full anticoagulant therapy and might warrant prophylactic
anticoagulation after first VTE during cancer treatment.
Keywords
venous thromboembolic disease - malignancy - paediatric - incidence - recurrence
