title: Long-term risks of subsequent primary neoplasms among survivors of childhood cancer.
abstract: BACKGROUND
  Survivors of childhood cancer are at excess risk of developing subsequent primary neoplasms but the long-term risks are uncertain.
  
  
  OBJECTIVE
  To investigate long-term risks of subsequent primary neoplasms in survivors of childhood cancer, to identify the types that contribute most to long-term excess risk, and to identify subgroups of survivors at substantially increased risk of particular subsequent primary neoplasms that may require specific interventions.
  
  
  METHODS
  British Childhood Cancer Survivor Study--a population-based cohort of 17,981 5-year survivors of childhood cancer diagnosed with cancer at younger than 15 years between 1940 and 1991 in Great Britain, followed up through December 2006.
  
  
  METHODS
  Standardized incidence ratios (SIRs), absolute excess risks (AERs), and cumulative incidence of subsequent primary neoplasms.
  
  
  RESULTS
  After a median follow-up time of 24.3 years (mean = 25.6 years), 1354 subsequent primary neoplasms were ascertained; the most frequently observed being central nervous system (n = 344), nonmelanoma skin cancer (n = 278), digestive (n = 105), genitourinary (n = 100), breast (n = 97), and bone (n = 94). The overall SIR was 4 times more than expected (SIR, 3.9; 95% confidence interval [CI], 3.6-4.2; AER, 16.8 per 10,000 person-years). The AER at older than 40 years was highest for digestive and genitourinary subsequent primary neoplasms (AER, 5.9 [95% CI, 2.5-9.3]; and AER, 6.0 [95%CI, 2.3-9.6] per 10,000 person-years, respectively); 36% of the total AER was attributable to these 2 subsequent primary neoplasm sites. The cumulative incidence of colorectal cancer for survivors treated with direct abdominopelvic irradiation was 1.4% (95% CI, 0.7%-2.6%) by age 50 years, comparable with the 1.2% risk in individuals with at least 2 first-degree relatives affected by colorectal cancer.
  
  
  CONCLUSIONS
  Among a cohort of British childhood cancer survivors, the greatest excess risk associated with subsequent primary neoplasms at older than 40 years was for digestive and genitourinary neoplasms.
authors.affiliation: Centre for Childhood Cancer Survivor Studies, School of Health and Population Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom. r.c.reulen@bham.ac.uk
authors.forename: Raoul C
authors.initials: RC
authors.lastname: Reulen
authors.forename: Clare
authors.initials: C
authors.lastname: Frobisher
authors.forename: David L
authors.initials: DL
authors.lastname: Winter
authors.forename: Julie
authors.initials: J
authors.lastname: Kelly
authors.forename: Emma R
authors.initials: ER
authors.lastname: Lancashire
authors.forename: Charles A
authors.initials: CA
authors.lastname: Stiller
authors.forename: Kathryn
authors.initials: K
authors.lastname: Pritchard-Jones
authors.forename: Helen C
authors.initials: HC
authors.lastname: Jenkinson
authors.forename: Michael M
authors.initials: MM
authors.lastname: Hawkins
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000628:therapy*; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D018570:Risk Assessment; D017741:Survivors; D006113:United Kingdom / Q000453:epidemiology