title: Subsequent Malignant Neoplasms in a Population-Based Cohort of Pediatric Cancer Patients: A Focus on the First 5 Years.
abstract: BACKGROUND
  The purpose was to describe the development of subsequent malignant neoplasms (SMN) among a population-based cohort of pediatric cancer patients, with a focus on SMNs that occurred within the first 5 years from diagnosis.
  
  
  METHODS
  The cohort was identified from POGONIS, an active provincial registry. Cohort members were Ontario residents ages 0 to 14.9 years at primary diagnosis between January 1985 and December 2008. SMNs that developed <18 years were captured by POGONIS, whereas SMNs diagnosed later were identified through linkage. Cumulative incidence and standardized incidence ratios (SIR) were calculated, and proportional hazards models were estimated to examine factors associated with SMN development.
  
  
  RESULTS
  A total of 7,920 patients were eligible. 2.4% (188/7,920) developed 197 SMNs. Mean follow-up time was 10.7 years (SD = 7.6 years; range, 0.0-26.4 years) with mean time to SMN of 8.5 years (SD = 6.3 years; range, 0.0-24.9 years). The SIR for the development of a SMN was 9.9 [95% confidence interval (CI), 8.6-11.4]. 40.6% of SMNs (80/197) developed within 5 years. Early SMNs were more likely to be leukemia and lymphoma. Factors associated with early SMN were primary diagnosis of a bone tumor (OR, 4.88; 95% CI, 1.52-15.60), exposure to radiotherapy (OR, 1.82; 95% CI, 1.02-3.22), and the highest dose of epipodophyllotoxin (OR, 3.74; 95% CI, 1.88-7.42).
  
  
  CONCLUSIONS
  Over 40% of SMNs diagnosed in childhood cancer patients occurred in the first 5 years after diagnosis, suggesting a need for early and ongoing surveillance.
  
  
  CONCLUSIONS
  The early development of certain SMNs reinforces the need for early and continued surveillance at all stages for pediatric cancer patients.
authors.affiliation: Pediatric Oncology Group of Ontario, Toronto, Ontario, Canada. Dalla Lana School of Public Health, University of Toronto, Ontario, Canada. jpole@pogo.ca.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Pole
authors.affiliation: Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Lan Ying
authors.initials: LY
authors.lastname: Gu
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Ontario, Canada. Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Victoria
authors.initials: V
authors.lastname: Kirsh
authors.affiliation: Pediatric Oncology Group of Ontario, Toronto, Ontario, Canada. The Hospital for Sick Children, Division of Hematology/Oncology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada. Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Greenberg
authors.affiliation: The Hospital for Sick Children, Division of Hematology/Oncology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Nathan
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009369:Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D009864:Ontario / Q000453:epidemiology; D011159:Population Surveillance / Q000379:methods*; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult