title: Time trends and age-period-cohort analyses on incidence rates of nasopharyngeal carcinoma during 1993-2007 in Wuhan, China.
abstract: BACKGROUND
  Declines in incidence rates of nasopharyngeal carcinoma (NPC) were observed in Hong Kong and Taiwan but not other high-risk regions in China, while evidences from low-risk regions in China are still lacking. This study aimed to examine the time trends (1993-2007) of NPC in Wuhan (a low-risk region) and assess the birth cohort and calendar period effects on the observed temporal trends.
  
  
  METHODS
  Using data from Wuhan Cancer Registry, age-standardized annual incidence rates of NPC were calculated by the direct method using the WHO World Standard Population (2000) as the reference. Trend in incidence rates of NPC during 1993-2007 was evaluated. Age-period-cohort models were also applied to assess the effects of age, calendar time and birth cohort on the observed temporal trends.
  
  
  RESULTS
  A total of 1685 new NPC cases (1210 males and 475 females) were diagnosed during 1993-2007 in Wuhan. The annual percentage change in incidence rates of NPC were 0.15% (95% confidence interval: -3.88% to 4.34%) for males and -1.17% (95% confidence interval: -4.85% to 2.66%) for females. No obvious cohort or period effect on the incidence rates of NPC was observed.
  
  
  CONCLUSIONS
  The incidence rates of NPC remained stable during 1993-2007 in Wuhan, a low-risk region in China.
authors.affiliation: School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Shao-Hua
authors.initials: SH
authors.lastname: Xie
authors.forename: Jie
authors.initials: J
authors.lastname: Gong
authors.forename: Nian-Nian
authors.initials: NN
authors.lastname: Yang
authors.forename: Lap-Ah
authors.initials: LA
authors.lastname: Tse
authors.forename: Ya-Qiong
authors.initials: YQ
authors.lastname: Yan
authors.forename: Ignatius Tak-Sun
authors.initials: IT
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology* / Q000401:mortality; D012042:Registries; D016019:Survival Analysis; D055815:Young Adult