Thromboembolism in Children with Sarcoma.

Background: Thromboembolism (TE) is one of the common causes of death in adults with cancer. Cancer is a major risk factor in children with TE and over 40% of children with central venous line (CVL)-related deep venous thrombosis (DVT) had underlying cancer. However, the epidemiology of TE in children with cancer, especially in association with childhood solid tumors is still unknown.

Objective: To define the prevalence and epidemiology of TE in association with sarcoma in children.

Methods: Hospital records of children ≤18 years of age with sarcoma diagnosed and treated at McMaster Children’s Hospital during January 1990 to September 2004 were reviewed for demographic details, details of diagnosis and therapy for sarcoma, and details of diagnosis and management of TE. Statistical analysis was performed using Fisher’s exact test.

Results: Seven of 63 (11.11%) patients with sarcoma developed TE (Table). Six patients had DVT and one patient had right atrial thrombosis. All, but one, patients had central venous line (CVL); three patients had CVL-associated DVT. Four of 28 girls (14.29%; 95% CI 5.7, 31.49) developed TE. Six of 36 patients ≥ 12 years of age developed TE (16.67%; 95% CI 7.87, 31.89) compared to 1 out of 27 (3.7%; 95% CI 0.66, 18.28) patients <12 years of age (p =0.222). Three out of 16 patients with metastatic disease at diagnosis developed TE (18.75%; 95% CI 6.59, 43.01) compared to 4 out of 47 (8.51%; 95% CI 3.36,19.93) (p=0.356) patients with localized disease. Six patients received anticoagulant therapy; one of these six patients required thrombectomy. Four patients received secondary thromboprophylaxis. One patient had recurrence of TE while being off of anticoagulant. Although none of the patients died because of TE or TE-related complication, patients with TE were at high risk for adverse outcome. Four out of 7 (57.1%) patients with TE have died compared to 22 of 56 (39.3%) patients without TE.

Conclusions: TE is a significant complication in children with sarcoma and may increase the risk of overall adverse outcome. Older patients and patients with Ewing’s sarcoma seem to be at are at higher, albeit statistically non-significant, risk of TE compared to younger patients and those with other types of sarcoma. Prospective studies of larger patient-populations are needed to define the epidemiology of TE in association with childhood sarcoma.