title: Second primary tumors in children and young adults in the North of England (1968-99).
abstract: BACKGROUND
  This study describes the risk of second malignancy in patients diagnosed with cancer under the age of 25 years, registered on the Northern Region Young Person's Malignant Disease Registry.
  
  
  METHODS
  Incidence rates were calculated to describe the occurrence of second malignancies, rate ratios were estimated to compare rates between subgroups. Standardized incidence ratios (SIRs) were calculated for comparison with a reference population.
  
  
  RESULTS
  There were 4,072 children and young adults diagnosed with a first malignancy from 1968 to 1999, of whom 68 had a second malignancy (including basal cell carcinomas and meningiomas). The incidence rate of second malignancy is 1.7 per 1,000 survivor person-years (95% CI: 1.4, 2.2), reflecting a four-fold increased risk of malignancy compared with the general population. The rate of second malignancy was non-significantly higher for those diagnosed during young adulthood rather than childhood (RR = 1.2, 95% CI: 0.7, 2.0), significantly higher in females than males (RR = 1.8, 95% CI: 1.1, 3.0) and significantly lower for those diagnosed in more recent years (RR = 0.4, 95% CI: 0.2, 0.8). In contrast, the SIRs indicated that children were at substantial increased risk; whilst males and females, and those diagnosed in earlier and later time periods, were at equivalent risks.
  
  
  CONCLUSIONS
  There is evidence of a sustained increased risk of second malignancy in those treated for primary cancer, especially those diagnosed in childhood; with no evidence that this risk is reducing.
authors.affiliation: School of Clinical Medical Sciences (Child Health), University of Newcastle Upon Tyne, United Kingdom. D.M.Hammal@ncl.ac.uk
authors.forename: Donna M
authors.initials: DM
authors.lastname: Hammal
authors.forename: Claire L
authors.initials: CL
authors.lastname: Bell
authors.forename: Alan W
authors.initials: AW
authors.lastname: Craft
authors.forename: Louise
authors.initials: L
authors.lastname: Parker
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012306:Risk; D017678:Sex Distribution