title: Relationship of Lifetime Exposure to Tobacco, Alcohol and Second Hand Tobacco Smoke with Upper aero-digestive tract cancers in India: a Case-Control Study with a Life-Course Perspective
abstract: Background: Squamous cell carcinomas of the upper aero-digestive tract (UADTSCC) are a multifaceted public
  health problem. Effects of lifestyle risk factors, including tobacco (chewing and smoking), alcohol drinking and exposure
  to second hand tobacco smoke (SHS) at home and their association with UADT cancers was assessed in a case-control
  study with a life-course perspective. The study was conducted at two different hospitals in Pune, India. Material and
  methods: The total sample size (N=480) included 240 histopathologically confirmed cases of UADT cancers and an
  equal number of controls frequency matched with cases by gender and age distribution (+5 years). All the patients were
  interviewed face-face using structured questionnaires. Self-reported information on socio-demographic and lifestyle
  risk factors from childhood to the date of diagnosis of disease/cancer was obtained. Frequency, duration and age of
  initiation of habits were also recorded to study dose-response relationships. Odds ratios and their 95% confidence
  intervals were calculated through unconditional logistic regression, adjusting for relevant potential confounders. Results:
  Chewing tobacco emerged as the strongest predictor for UADT cancers (OR=7.61; 95% CI 4.65-12.45) in comparison
  to smoking and drinking alcohol. Exposure to SHS during childhood (<16 years) rather than ≥16 years increased the
  risk (OR=4.05; 95% CI 2.06-7.95). Combined effects of tobacco and alcohol consumption habits elevated the risk by
  twelve fold (OR=12.05; 95% 4.61-31.49) in comparison to never users of these habits. Furthermore, the combination of
  these lifestyle risk factors accounted for 86.8% of population attributable risk. Conclusions: Early exposure to various
  modifiable lifestyle risk factors has a strong positive association with UADT cancer incidence. Effective future public
  health interventions with focus on vital time points in life targeting these risk factors could possibly be a major step in
  primary prevention and control of this cancer at the population level.
authors.affiliation: School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia. Email:bhawna.gupta@griffithuni.edu.au
authors.forename: Bhawna
authors.initials: B
authors.lastname: Gupta
authors.forename: Narinder
authors.initials: N
authors.lastname: Kumar
authors.forename: Newell W
authors.initials: NW
authors.lastname: Johnson
keywords: Upper aero-digestive tract cancer; chewing tobacco; smoking; alcohol; second hand tobacco smoke