Age at cancer diagnosis, non-O blood group and asparaginase therapy are independently associated with deep venous thrombosis in pediatric oncology patients: A risk model.
BACKGROUND
Pediatric oncology patients are at increased risk for deep venous thrombosis (DVT). Determining the sub-population of children at increased DVT risk is critical for optimum clinical management. Therefore, the aim of the current study was to identify clinical risk factors for DVT which are easily identifiable at cancer diagnosis.


METHODS
A Canadian multicenter case control study in survivors of childhood cancer. Survivors who had DVT (Cases) while being treated for pediatric cancer where matched by center with a minimum of two survivors who did not experience DVT (Controls). Clinical information including age at diagnosis, type of cancer and chemotherapy were collected. Genotyping of blood group was done by single nucleotide polymorphisms analysis.


RESULTS
218 subjects were recruited at 4 Canadian pediatric centers. Multivariable analysis demonstrated 3 significant variables (reported as Odds Ratio (OR), (95% CI), p value): age at diagnosis p<0.001, non-O blood group OR 2.6 (1.3-5.2) p=0.005 and asparaginase treatment OR 2.4 (1.2-4.8) p=0.011. In order to optimise clinical utility, we reanalysed the study data with age at diagnosis categorised into four subgroups 0-≤2years, >2-≤7years, >7≤10years, >10years. A significant association with DVT were seen in children 0-≤2years (OR 3.1 (1.1-8.3) p=0.026) and >10years (OR 3.8, 1.7-8.5 p=0.001). Significant associations with DVT remained for non-O blood group, OR 2.2 (1.2-4.4) p=0.016 and asparaginase treatment, OR 2.1 (1.1-4.0) p=0.027. The value for the clinical risk model receiver operating characteristics curve was 0.67.


CONCLUSIONS
We have shown 3 independent risk factors for DVT in childhood cancer.
University of Alberta, Edmonton, Alberta, Canada.
Maria
M
Spavor
Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
Jacqueline
J
Halton
University of Alberta, Edmonton, Alberta, Canada.
Kevin
K
Dietrich
Cancer Care Manitoba, Winnipeg, Manitoba, Canada.
Sara
S
Israels
BC Children's Hospital, Vancouver, British Columbia, Canada.
Evan
E
Shereck
University of Alberta, Edmonton, Alberta, Canada.
Jian
J
Yong
University of Alberta, Edmonton, Alberta, Canada.
Yutaka
Y
Yasui
University of Alberta, Edmonton, Alberta, Canada. Electronic address: lesley.mitchell@albertahealthservices.ca.
Lesley Gayle
LG
Mitchell
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001215:Asparaginase / Q000009:adverse effects* / Q000627:therapeutic use; D001789:Blood Group Antigens / Q000097:blood*; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D006801:Humans; D009369:Neoplasms / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy*; D016017:Odds Ratio; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D055815:Young Adult
D000970:Antineoplastic Agents; D001789:Blood Group Antigens; D001215:Asparaginase
Deep venous thrombosis; Oncology; Pediatrics; Risk Factors