title: Hookah smoking, nass chewing, and oesophageal squamous cell carcinoma in Kashmir, India.
abstract: BACKGROUND
  Although cigarette smoking is an established risk factor for oesophageal squamous cell carcinoma (ESCC), there is little information about the association between other smoking and smokeless tobacco products, including hookah and nass, and ESCC risk. We conducted a case-control study in Kashmir Valley, India, where hookah smoking, nass chewing, and ESCC are common, to investigate the association of hookah smoking, nass use, and several other habits with ESCC.
  
  
  METHODS
  We recruited 702 histologically confirmed ESCC cases and 1663 hospital-based controls, individually matched to the cases for age, sex, and district of residence from September 2008 to January 2012. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).
  
  
  RESULTS
  Ever-hookah smoking (OR=1.85; 95% CI, 1.41-2.44) and nass chewing (OR=2.88; 95% CI, 2.06-4.04) were associated with ESCC risk. These associations were consistent across different measures of use, including intensity, duration, and cumulative amount of use, and after excluding ever users of the other product and cigarette smokers. Our results also suggest an increased risk of ESCC associated with ever-gutka chewing and -bidi smoking. However, the latter associations were based on small number of participants.
  
  
  CONCLUSIONS
  This study shows that hookah and nass use are associated with ESCC risk. As prevalence of hookah use seems to be increasing among young people worldwide, these results may have relevance not only for the regions in which hookah use has been a traditional habit, but also for other regions, including western countries.
authors.affiliation: Department of Biochemistry, University of Kashmir, Hazratbal, Srinagar 190006, India. nazirramzan@gmail.com
authors.forename: N A
authors.initials: NA
authors.lastname: Dar
authors.forename: G A
authors.initials: GA
authors.lastname: Bhat
authors.forename: I A
authors.initials: IA
authors.lastname: Shah
authors.forename: B
authors.initials: B
authors.lastname: Iqbal
authors.forename: M A
authors.initials: MA
authors.lastname: Makhdoomi
authors.forename: M A
authors.initials: MA
authors.lastname: Kakhdoomi
authors.forename: I
authors.initials: I
authors.lastname: Nisar
authors.forename: R
authors.initials: R
authors.lastname: Rafiq
authors.forename: S T
authors.initials: ST
authors.lastname: Iqbal
authors.forename: A B
authors.initials: AB
authors.lastname: Bhat
authors.forename: S
authors.initials: S
authors.lastname: Nabi
authors.forename: S A
authors.initials: SA
authors.lastname: Shah
authors.forename: R
authors.initials: R
authors.lastname: Shafi
authors.forename: A
authors.initials: A
authors.lastname: Masood
authors.forename: M M
authors.initials: MM
authors.lastname: Lone
authors.forename: S A
authors.initials: SA
authors.lastname: Zargar
authors.forename: M S
authors.initials: MS
authors.lastname: Najar
authors.forename: F
authors.initials: F
authors.lastname: Islami
authors.forename: P
authors.initials: P
authors.lastname: Boffetta
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D004938:Esophageal Neoplasms / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000008:administration & dosage* / Q000009:adverse effects; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*
chemical_list: D010936:Plant Extracts; C015378:nas