title: Consumption of cigarettes but not betel quid or alcohol increases colorectal cancer risk.
abstract: OBJECTIVE
  The effect of betel quid chewing on colorectal cancer (CRC) risk has not been reported. In addition, there is no consensus about the causal relationship between smoking or alcohol consumption and CRC risk. This study investigated the impact of betel quid chewing, cigarette smoking or alcohol consumption on CRC risk in Taiwan.
  
  
  METHODS
  Two hundred and fifty-eight patients with pathologically proven CRC (153 men, 105 women; mean age, 63.1 years) were recruited from two hospitals in southern Taiwan. The controls were 533 age- and gender-matched cancer-free subjects from the same hospitals. All subjects were interviewed using a standardized questionnaire to collect demographic and substance use data.
  
  
  RESULTS
  After adjusting for potential confounding factors, smoking (adjusted odds ratio [aOR], 1.65; 95% CI, 1.1-2.3), but not betel quid chewing (aOR, 1.3; 95% CI, 0.7-2.4) or alcohol drinking (aOR, 1.1; 95% CI, 0.7-1.8), was an independent significant risk factor for developing CRC. The significant risk effect of smoking was seen mainly among men, because the frequency of smokers was much higher among Taiwanese men than women.
  
  
  CONCLUSIONS
  Our results indicated that consumption of cigarettes but not betel quid or alcohol was a risk factor for male CRC. A large study is necessary to investigate the risk factors for female CRC in Taiwan, and to understand the effect of betel quid exposure on male CRC.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Graduate Institutes of Medicine, College of Medicine, Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: I-Chen
authors.initials: IC
authors.lastname: Wu
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Lee
authors.forename: Chao-Hung
authors.initials: CH
authors.lastname: Kuo
authors.forename: Fu-Chen
authors.initials: FC
authors.lastname: Kuo
authors.forename: Deng-Chyang
authors.initials: DC
authors.lastname: Wu
authors.forename: Ying-Chin
authors.initials: YC
authors.lastname: Ko
authors.forename: Fang-Jung
authors.initials: FJ
authors.lastname: Yu
mesh_terms: D000428:Alcohol Drinking / Q000453:epidemiology*; D001114:Areca; D016022:Case-Control Studies; D015984:Causality; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology