title: Combined effect of tobacco and alcohol on laryngeal cancer risk: a case-control study.
abstract: OBJECTIVE
  To provide information on the effects of alcohol and tobacco on laryngeal cancer and its subsites.
  
  
  METHODS
  This was a case-control study conducted between 1992 and 2000 in northern Italy and Switzerland. A total of 527 cases of incident squamous-cell carcinoma of the larynx and 1297 hospital controls frequency-matched with cases on age, sex, and area of residence were included. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using multiple logistic regression.
  
  
  RESULTS
  In comparison with never smokers, ORs were 19.8 for current smokers and 7.0 for ex-smokers. The risk increased in relation to the number of cigarettes (OR = 42.9 for > or = 25 cigarettes/day) and for duration of smoking (OR = 37.2 for > or = 40 years). For alcohol, the risk increased in relation to number of drinks (OR = 5.9 for > or = 56 drinks per week). Combined alcohol and tobacco consumption showed a multiplicative (OR = 177) rather than an additive risk. For current smokers and current drinkers the risk was higher for supraglottis (ORs 54.9 and 2.6, respectively) than for glottis (ORs 7.4 and 1.8) and others subsites (ORs 10.9 and 1.9).
  
  
  CONCLUSIONS
  Our study shows that both cigarette smoking and alcohol drinking are independent risk factors for laryngeal cancer. Heavy consumption of alcohol and cigarettes determined a multiplicative risk increase, possibly suggesting biological synergy.
authors.affiliation: Servizio di Epidemiologia, Centro di Riferimento Oncologico, Istituto Nazionale Tumori, Aviano, Italy. talaminir@cro.it
authors.forename: R
authors.initials: R
authors.lastname: Talamini
authors.forename: C
authors.initials: C
authors.lastname: Bosetti
authors.forename: C
authors.initials: C
authors.lastname: La Vecchia
authors.forename: L
authors.initials: L
authors.lastname: Dal Maso
authors.forename: F
authors.initials: F
authors.lastname: Levi
authors.forename: E
authors.initials: E
authors.lastname: Bidoli
authors.forename: E
authors.initials: E
authors.lastname: Negri
authors.forename: C
authors.initials: C
authors.lastname: Pasche
authors.forename: S
authors.initials: S
authors.lastname: Vaccarella
authors.forename: L
authors.initials: L
authors.lastname: Barzan
authors.forename: S
authors.initials: S
authors.lastname: Franceschi
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects*; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007822:Laryngeal Neoplasms / Q000453:epidemiology / Q000209:etiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013557:Switzerland / Q000453:epidemiology