Venous Thromboembolism in Pediatric Bone Sarcoma Patients: A 10‐Year, Single‐Institution Experience Encompassing the COVID‐19 Pandemic

BACKGROUND: Osteosarcoma (OS) and Ewing sarcoma (EWS) are the most common primary bone cancers in children, but acute thrombosis is poorly characterized in this population. Our study evaluated the rates of venous thromboembolism (VTE) and associated risk factors in pediatric patients with bone sarcomas treated over a 10-year period encompassing the emergence of COVID-19. PROCEDURE: Data were obtained via EMR review for patients diagnosed with OS and EWS at Texas Children's Hospital from 2014 to 2023. Statistical analyses were performed using Fisher's exact, chi-square, and Wilcoxon rank-sum tests. Change in VTE rate prior to and after 2020 was compared using interrupted time series analysis. RESULTS: Among 137 eligible patients, the majority were diagnosed with OS (n = 85, 62%) compared to EWS (n = 52, 38%). Twelve patients (8.8%) developed VTEs during primary cancer therapy. Femoral tumor location was associated with increased VTE occurrence (p = 0.016), and there was a trend toward increased VTE in OS (p = 0.13) and obese patients (p = 0.2). VTE rates increased after the emergence of COVID-19, although only one affected patient tested positive. The incidence rate ratio pre- and post-COVID-19 emergence (2014-2019 vs. 2020-2023) was 8.7 (95% CI: 2.29-56.61; p = 0.005). This increase in VTEs after 2020 was sustained. CONCLUSION: Our cohort represents the largest population of pediatric patients with bone sarcomas studied to date. In our 10-year analysis, we observed a sustained increase in VTE events following the emergence of COVID-19. Additionally, our data suggest that subsets of this patient population, specifically obese patients with OS and femoral tumors, should be closely monitored for thrombosis.