title: The incidence and risk of second primary cancers in patients with nasopharyngeal carcinoma: a population-based study in Taiwan over a 25-year period (1979-2003).
abstract: BACKGROUND
  Very few reports are available on the incidence and risk of second primary cancers in nasopharyngeal carcinoma (NPC) cases, and most of these are single-institution reviews with relatively small case numbers and short follow-up.
  
  
  METHODS
  A population-based study was conducted. We quantified standardized incidence ratios (SIRs) and cumulative incidence of second cancers among 23 639 individuals with initial diagnoses of NPC.
  
  
  RESULTS
  We found a 24% increased risk of second cancers in NPC patients compared with the general population [SIR = 1.24, 95% confidence interval 1.15-1.33]. Elevated SIRs were observed in the following second primary cancers: oral/pharyngeal, salivary gland, sarcoma, skin and leukemia/lymphoma. The cumulative incidence >10 years was 3.26%. The risk was higher in younger patients, especially those <40 years old. After diagnosis of second cancers, the median survival time was 1.7 years.
  
  
  CONCLUSIONS
  This is the largest population-based study to date from a high-incidence area. We found that NPC is associated with an increased risk of second malignancies, which had a negative impact on the survival of patients who survived NPC.
authors.affiliation: Department of Public Health and Biostatistics Consulting Center, School of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: M-C
authors.initials: MC
authors.lastname: Chen
authors.forename: I-J
authors.initials: IJ
authors.lastname: Feng
authors.forename: C-H
authors.initials: CH
authors.lastname: Lu
authors.forename: C-C
authors.initials: CC
authors.lastname: Chen
authors.forename: J-T
authors.initials: JT
authors.lastname: Lin
authors.forename: S-H
authors.initials: SH
authors.lastname: Huang
authors.forename: K-D
authors.initials: KD
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology*; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology