title: Tobacco and alcohol as risk factors for oesophageal cancer in a high incidence area in South Africa.
abstract: BACKGROUND
  The Eastern Cape Province of South Africa, which includes the former Transkei has high rates of squamous cell oesophageal cancer (OC), thought to be caused mainly by nutritional deficiencies and fungal contamination of staple maize. A hospital-based case-control study was conducted at three of the major referral hospitals in this region to measure, among other suspected risk factors, the relative importance of tobacco smoking and alcohol consumption for the disease in this population.
  
  
  METHODS
  Incident cases (n=670) of OC and controls (n=1188) were interviewed using a structured questionnaire which included questions on tobacco and alcohol-related consumption. Odds ratios (ORs) with 95% confidence intervals for each of the risk factors were calculated using unconditional multiple logistic regression models.
  
  
  RESULTS
  A monotonic dose-response was observed across the categories of each tobacco-related variable in both sexes. Males and females currently smoking a total of >14g of tobacco per day were observed to have over 4-times the odds of developing OC (males OR=4.36, 95% CI 2.24-8.48; females OR=4.56, 95% CI 1.46-14.30), with pipe smoking showing the strongest effect. Similar trends were observed for the alcohol-related variables. The quantity of ethanol consumed was the most important factor in OC development rather than any individual type of alcoholic beverage, especially in smokers. Males and females consuming >53g of ethanol per day had approximately 5-times greater odds in comparison to non-drinkers (males OR=4.72, 95% CI 2.64-8.41; females OR=5.24, 95% CI 3.34-8.23) and 8.5 greater odds in those who smoked >14g tobacco daily. The attributable fractions for smoking and alcohol consumption were 58% and 48% respectively, 64% for both factors combined.
  
  
  CONCLUSIONS
  Tobacco and alcohol use are major risk factors for OC development in this region.
  
  
  CONCLUSIONS
  This study provides evidence for further reinforcement of cessation of smoking and alcohol consumption to curb OC development.
authors.affiliation: African Cancer Institute, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town 8000, South Africa; Division of Community Health, Department of Interdisciplinary Health Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town 8000, South Africa. Electronic address: vsewram@sun.ac.za.
authors.forename: Vikash
authors.initials: V
authors.lastname: Sewram
authors.affiliation: Cancer Research Division, Cancer Council New South Wales, P.O. Box 572, Kings Cross, NSW 1340, Australia; Sydney School of Public Health, University of Sydney, Camperdown, Australia; School of Public Health and Community Medicine, University of New South Wales, Kensington, Australia.
authors.forename: Freddy
authors.initials: F
authors.lastname: Sitas
authors.affiliation: Cancer Research Division, Cancer Council New South Wales, P.O. Box 572, Kings Cross, NSW 1340, Australia; Sydney School of Public Health, University of Sydney, Camperdown, Australia; School of Public Health and Community Medicine, University of New South Wales, Kensington, Australia; School of Medicine and Public Health, University of Newcastle, Australia.
authors.forename: Dianne
authors.initials: D
authors.lastname: O'Connell
authors.affiliation: Centre for Occupational and Environmental Health Research, School of Public Health and Family Medicine, University of Cape Town, Observatory 7925, South Africa.
authors.forename: Jonny
authors.initials: J
authors.lastname: Myers
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D004938:Esophageal Neoplasms / Q000453:epidemiology* / Q000209:etiology; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013019:South Africa / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: Alcohol; Attributable proportion; Oesophageal cancer; Risk factors; South Africa; Tobacco