Thromboembolic events in children and young adults with pediatric sarcoma

Purpose: Adults with malignancy are at increased risk for venous thromboembolic events (TEs). However, data in children and young adults with cancer are limited. Patients and Methods: To determine the risk and clinical features of TEs in children and young adults with sarcoma, we reviewed records on 122 consecutive patients with sarcoma treated from October 1980 to July 2002. Results: Twenty-three TEs were diagnosed in 19 of 122 (16%; 95% CI, 10% to 23%) patients. Prevalence by diagnosis was Ewing sarcoma, eight of 61 (13%); osteosarcoma, two of 20 (10%); rhabdomyosarcoma, four of 26 (15%); and other sarcomas, five of 15 (33%). TEs developed in 23% of patients with metastases at presentation versus 10% with localized disease (odds ratio, 2.59; 95% CI, 0.9 to 7.1; P < .06). Fifty-three percent of patients with thrombosis had a clot at presentation. A lupus anticoagulant was detected in four of five evaluated patients. There was a single fatality due to pulmonary embolism. Patients who were diagnosed with cancer after 1993 had a higher rate of TE (7% v 23%; P < .015). Of the 23 events, 43% were asymptomatic. Main sites of thromboses were deep veins of the extremities (10 of 23; 43%), pulmonary embolism (five of 23; 22%), and the inferior vena cava (four of 23; 17%). TEs were associated with tumor compression in eight of 23 (35%) and with venous catheters in three of 23 (13%). Conclusion: Thromboembolism is common in pediatric patients with sarcomas. Thromboses are detected frequently around the time of oncologic presentation, may be asymptomatic, and seem to be associated with a higher disease burden. Children and young adults with sarcoma should be monitored closely for thrombosis.