title: Epidemiology and clinical risk factors predisposing to thromboembolism in children with cancer.
abstract: OBJECTIVE
  The prevalence and risk factors for thromboembolism (TE) in children with cancer are largely unknown. This retrospective cohort study aims to determine the epidemiology of TE and to identify potential risk factors for TE in children with cancer.
  
  
  METHODS
  We used logistic regression to determine the association of age (<10 years vs. > or =10 years), gender, type of cancer, presence or absence of intra-thoracic disease (mediastinal mass or any primary or metastatic pulmonary disease), type of central venous line (CVL) and CVL-dysfunction (difficulty of blood draw, infusion or documented CVL infection) on the risk of developing TE.
  
  
  RESULTS
  Fifty-seven of 726 patients [7.9%; 95% confidence intervals (CI); 6.0,10.0] developed TE; children with brain tumors (n = 201) had significantly lower prevalence of TE (0.5%; P < 0.001). Older patients had increased risk of developing TE compared to younger patients [Odds ratios (OR) 1.8; 95% CI; 1.0,3.2; P = 0.036]. Children with acute lymphoblastic leukemia (ALL) (OR 4.6; 95% CI; 1.8, 12.3; P = 0.002), lymphoma (OR 3.8; 95% CI; 1.3, 11.1; P = 0.016), and sarcoma (OR 4.3; 95% CI; 1.4, 13.3; P = 0.012) had an increased risk of TE. Subgroup analyses showed that patients with CVL-dysfunction and intra-thoracic disease had a higher prevalence of TE compared to those without CVL-dysfunction (22.8% vs. 8.8%; 95% CI; 4.0, 24.3; P = 0.006) and intra-thoracic disease (18.0% vs. 6.1%; 95% CI; 2.4, 21.4; P = 0.02).
  
  
  CONCLUSIONS
  TE is common in children with cancer. Age and type of cancer are independent risk factors for TE in children with non-CNS cancers. CVL-dysfunction and intra-thoracic disease are significantly associated with the diagnosis of TE.
authors.affiliation: Division of Hematology/Oncology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada. athaleu@mcmaster.ca
authors.forename: Uma
authors.initials: U
authors.lastname: Athale
authors.forename: Sabrina
authors.initials: S
authors.lastname: Siciliano
authors.forename: Lehana
authors.initials: L
authors.lastname: Thabane
authors.forename: Nikhil
authors.initials: N
authors.lastname: Pai
authors.forename: Stephanie
authors.initials: S
authors.lastname: Cox
authors.forename: Anita
authors.initials: A
authors.lastname: Lathia
authors.forename: Anees
authors.initials: A
authors.lastname: Khan
authors.forename: Ankelly
authors.initials: A
authors.lastname: Armstrong
authors.forename: Anthony K C
authors.initials: AK
authors.lastname: Chan
mesh_terms: D001932:Brain Neoplasms / Q000150:complications / Q000628:therapy; D002405:Catheterization, Central Venous / Q000009:adverse effects; D002648:Child; D015331:Cohort Studies; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D008223:Lymphoma / Q000150:complications / Q000628:therapy; D008297:Male; D009369:Neoplasms / Q000473:pathology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D012509:Sarcoma / Q000150:complications / Q000628:therapy; D013923:Thromboembolism / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology