title: [A case-control study on non-smoking primary lung cancers in Sichuan, China].
abstract: OBJECTIVE
  The incidence of lung cancer in non-smokers is increasing in recent years. The aim of this investigation is to explore main risk factors of non-smoking primary lung cancers in Sichuan province in order to provide more accurate data for clinical.
  
  
  METHODS
  One hundred and fourty-five non-smoking pairs of cases and 145 of controls were matched by age and sex. The patients were newly-diagnosed definitely as primary lung cancer at West China Hospital of Sichuan University from March to December 2009.
  
  
  RESULTS
  Seventeen exposure factors were explored as epidemic agents for non-smoking lung cancer in Sichuan by using univariate analysis; mutivariate conditional Logistic regression analysis showed that passive smoking, moved into newly renovated homes over the past 10 years, family cancer history from second/ third-degree relatives, lack of emotion regulation, heavy work pressure and poor quality of sleep were main risk agents for the non-smoking lung cancer incidence with OR 2.267 (95% CI: 1.231-4.177), 5.080 (95% CI: 1.632-15.817), 7.937 (95% CI: 1.815-34.705), 2.491 (95% CI: 1.230-4.738), 5.769 (95% CI: 2.030-16.396), 2.538 (95% CI: 1.277-4.861), respectively. While higher body mass index, eating fruit and vegetable and regular participating in physical exercise might be protective factors with OR 0.419 (95% CI: 0.226-0.779), 0.344 (95% CI: 0.155-0.762), 0.507 (95% CI: 0.274-0.937), respectively.
  
  
  CONCLUSIONS
  The occurrence of non-smoking primary lung cancer associated with a variety of exposure factors including passive smoking, history of exposure to harmful environmental, family cancer history, mental and psychological factors in Sichuan Province.
authors.affiliation: Department of Thoracic Cancer, Cancer Center, West China Hospital, Chengdu 610041, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Jiang
authors.forename: Huan
authors.initials: H
authors.lastname: Song
authors.forename: Xiaying
authors.initials: X
authors.lastname: Peng
authors.forename: Libo
authors.initials: L
authors.lastname: Yan
authors.forename: Min
authors.initials: M
authors.lastname: Yu
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Haoshu
authors.initials: H
authors.lastname: Liu
authors.forename: Feifei
authors.initials: F
authors.lastname: Liu
authors.forename: You
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002681:China; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking