Incidence of venous thromboembolism in children with primary lymphomas

Abstract

Cancer increases the risk of venous thromboembolism (VTE) in adults and children. The aim of our study was to evaluate the incidence of VTE in children and adolescents with lymphomas. The study was approved by the Independent Ethics Committee of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. A retrospective analysis based on medical data of 262 children and adolescents (0–18 years) with primary lymphomas (n = 262) who were treated in Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology since 01.01.2013 to 31.12.2019 had been performed. Such parameters as age and sex distribution of patients, the frequency, as well as the cumulative incidence of detection (CI) and differences in localization, the median time of detection of symptomatic (sVTE) and asymptomatic episodes of VT (aVTE), their relationship with central venous catheters (CVC) were analyzed. Statistical processing of the obtained data was carried out using the XLSTAT 2020 program (Addinsoft, France). The median age was 11,1 years (interquartile range (IQR) 6.5–15 years), the ratio of males to females was 2.2:1. There were 71 episodes of VTE in 65 patients (24.8%, 95% confidence interval (CI): 19.6–30). Among all episodes of VTE 31% were defined as sVTE at 400 day CI for sVTE was found to be 8.1% (95% CI: 5.4–12.2) and CI for aVTE – 18.7% (95% CI: 14.4–24.2). The median time to VTE episode was 38 days (IQR 16.5–91.5 days). There was a trend towards an earlier diagnosis of sVTE (median 23.5 days, IQR – 17–42 days) than aVTE (median 62 days, IQR 14–80 days), p = 0.075. VTE was CVC-related in 67.7 of all VTE cases. In one case, asymptomatic thrombosis of right atrium led to pulmonary embolism (PE). VTE is a frequent complication in children and adolescents with lymphomas. Most episodes of VTE were asymptomatic, one of which was the most likely cause of PE in the child. Further research is needed to find risk factors for VTE.