title: Second primary cancers in patients with nasopharyngeal carcinoma: a pooled analysis of 13 cancer registries.
abstract: OBJECTIVE
  To study the risk of second primary cancers in nasopharyngeal carcinoma (NPC) patients and the risk of NPC as second primary cancer.
  
  
  METHODS
  We used data from the cancer registries from Singapore and from 12 low-incidence areas, including a total of 8,947 first occurring NPC cases, and 167 second occurring cases. We calculated standardized incidence ratios (SIRs) by comparing the second cancer incidence in NPC patients to the first primary cancer incidence in non-cancer population. We also calculated SIRs of second NPC after other primaries.
  
  
  RESULTS
  In Singapore, the risk of cancers of the lung (SIR=0.42), stomach (SIR=0.41), and colon (SIR=0.23) was significantly decreased after NPC, whereas that of cancer of the tongue (SIR=11.1) was significantly increased. In Australia, Canada, and Europe, the risk of non-Hodgkin's lymphoma (NHL) (SIR=3.06), tongue cancer (SIR=5.29), brain cancer (SIR=3.89), myeloid leukemia (SIR=3.85), and non-melanoma skin cancer (NMSC) (SIR=3.47) was significantly increased after NPC. Incidences of second occurring NPCs following various primary cancers were not significantly altered compared to the incidence of first occurring NPCs.
  
  
  CONCLUSIONS
  Immune suppression (NHL, NMSC), shared genetic factors (lung cancer, NHL, myeloid leukemia), and shared environmental risk factors (tongue and brain cancers) might explain the associations. Except for NHL, there was no evidence of association with other Epstein-Barr virus-related cancers.
authors.affiliation: International Agency for Research on Cancer, 150 cours Albert Thomas, Lyon, 69008, France.
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Scélo
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
authors.forename: Marilys
authors.initials: M
authors.lastname: Corbex
authors.forename: Kee-Seng
authors.initials: KS
authors.lastname: Chia
authors.forename: Kari
authors.initials: K
authors.lastname: Hemminki
authors.forename: Soren
authors.initials: S
authors.lastname: Friis
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
authors.forename: Elisabete
authors.initials: E
authors.lastname: Weiderpass
authors.forename: Mary L
authors.initials: ML
authors.lastname: McBride
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tracey
authors.forename: David H
authors.initials: DH
authors.lastname: Brewster
authors.forename: Vera
authors.initials: V
authors.lastname: Pompe-Kirn
authors.forename: Erich V
authors.initials: EV
authors.lastname: Kliewer
authors.forename: Jon M
authors.initials: JM
authors.lastname: Tonita
authors.forename: Carmen
authors.initials: C
authors.lastname: Martos
authors.forename: Jon G
authors.initials: JG
authors.lastname: Jonasson
authors.forename: Paul
authors.initials: P
authors.lastname: Brennan
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology*; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012042:Registries; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology