title: Association between oral leukoplakia and upper gastrointestinal cancers: a 28-year follow-up study in the Linxian General Population Trial.
abstract: BACKGROUND
  Oral leukoplakia is a precancerous disorder that is common among residents in Linxian. However, the associations between oral leukoplakia and upper gastrointestinal cancers have not been reported. We investigated the relationships between oral leukoplakia and upper gastrointestinal cancers in the Linxian General Population Trial cohort.
  
  
  METHODS
  The Linxian General Population Trial cohort, with 29,584 healthy adults enrolled in 1985 and followed through the end of 2012. With collected baseline data, hazard ratios (HR) and 95% confidence intervals (95% CI) for developing upper gastrointestinal cancers were estimated using Cox proportional hazard models.
  
  
  RESULTS
  During 28 years of follow-up, we confirmed a total of 2924 incident esophageal squamous cell carcinoma (ESCC) cases, 1644 gastric cardia cancers and 590 gastric non-cardia cancers. Overall, participants with oral leukoplakia had significantly higher risk of developing ESCC (HR=1.18, 95% CI: 1.08, 1.29). Among individuals ⩽52 years old at baseline, oral leukoplakia was associated with elevated risk of ESCC (HR=1.31, 95%CI: 1.15, 1.49). No significant associations were observed for gastric cardia or non-cardia cancers in either all subjects or subgroups.
  
  
  CONCLUSIONS
  Oral leukoplakia was associated with increased risk of ESCC, particularly in younger population. Future studies are needed to confirm these findings.
authors.affiliation: Department of Cancer Epidemiology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: J-H
authors.initials: JH
authors.lastname: Fan
authors.affiliation: Department of Cancer Epidemiology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Department of Epidemiology and Health Statistics, School of Public Health, Zhejiang University, Hangzhou, China.
authors.forename: J-B
authors.initials: JB
authors.lastname: Wang
authors.affiliation: Department of Cancer Epidemiology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: C-X
authors.initials: CX
authors.lastname: Qu
authors.affiliation: Department of Cancer Epidemiology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Y-Q
authors.initials: YQ
authors.lastname: Zhang
authors.affiliation: Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, USA.
authors.forename: P R
authors.initials: PR
authors.lastname: Taylor
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Abnet
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Dawsey
authors.affiliation: Department of Cancer Epidemiology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China. Electronic address: qiaoy@cicams.ac.cn.
authors.forename: Y-L
authors.initials: YL
authors.lastname: Qiao
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D004938:Esophageal Neoplasms / Q000150:complications* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007972:Leukoplakia, Oral / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000150:complications* / Q000453:epidemiology
keywords: Esophageal squamous cell carcinoma; Gastric cardia carcinoma; Gastric non-cardia carcinoma; Linxian General Population Trial; Oral leukoplakia