title: Betel quid chewing and upper aerodigestive tract cancers: a prospective cohort study in khon kaen, Thailand.
abstract: BACKGROUND
  This study aimed to determine the association between betel quid chewing and the occurrence of upper aerodigestive tract (UADT) cancers.
  
  
  METHODS
  A cohort of 17,388 subjects, recruited and interviewed over the 1990-2001 period, in Khon Kaen, Thailand, was followed up until 2011. The data were linked to the Khon Kaen Population-Based Cancer Registry.
  
  
  RESULTS
  The prevalence of betel quid chewing was 15.9%, with a female predominance (97.7%); the mean age of chewers was 57.7 years (SD 6.6). The overall incidence of UADT cancers from the cohort was 14.7 per 100,000 person-years, whereas the incidence among the chewers was 45.7. Betel nut chewing was the only major risk factor for UADT cancers in this population (HR=5.26, 95%CI=2.51- 11.0), while weak associations were found for tobacco smoking and alcohol (HR=1.16, 95%CI=0.45-3.01 and 1.47, 95%CI=0.72-3.03 respectively).
  
  
  CONCLUSIONS
  We found betel quid chewing to be a main risk factor for UADT cancers, resulting in a higher incidence in females. However, further study is required to explore the potential risk factors among non-chewers, non-smokers, and non-drinkers.
authors.affiliation: Nongkungsri Public Health Office, Kalasin, Thailand.
authors.forename: Wilas
authors.initials: W
authors.lastname: Kampangsri
authors.forename: Patravoot
authors.initials: P
authors.lastname: Vatanasapt
authors.forename: Siriporn
authors.initials: S
authors.lastname: Kamsa-Ard
authors.forename: Krittika
authors.initials: K
authors.lastname: Suwanrungruang
authors.forename: Supannee
authors.initials: S
authors.lastname: Promthet
mesh_terms: D000328:Adult; D000368:Aged; D001114:Areca / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects*; D013785:Thailand / Q000453:epidemiology