title: Smoking increases the risk for colorectal adenomas in patients with Lynch syndrome.
abstract: OBJECTIVE
  Individuals with Lynch syndrome have a high risk of developing colorectal carcinomas and adenomas at a young age, due to inherited mutations in mismatch repair genes. We investigated whether modifiable lifestyle factors, such as smoking and alcohol intake, increase this risk.
  
  
  METHODS
  Using data from the GeoLynch cohort study, a prospective analysis of 386 subjects with Lynch syndrome, we calculated hazard ratios for the association between smoking and alcohol intake and development of colorectal adenoma. We used robust variance estimates in the calculation of 95% confidence intervals to account for dependency within families and adjusted for confounding by age, sex, smoking (in the analyses of alcohol intake), number of colonoscopies during the follow-up, colonic resection, and body mass index.
  
  
  RESULTS
  During a median follow-up of 10 months, 58 subjects developed a histologically confirmed colorectal adenoma. The hazard ratio for current smokers was 6.13 (95% confidence interval, 2.84-13.22) and for former smokers was 3.03 (95% confidence interval, 1.49-6.16) compared with never smokers. Among ever smokers, a higher number of pack-years was associated with an increased risk for colorectal adenoma (P for trend = .03). There was a trend of alcohol intake increasing the risk of colorectal adenomas, although this was not statistically significant; the hazard ratio for the highest tertile of intake (median, 22 g/day) vs the lowest tertile (median, 0.4 g/day) was 1.56 (95% confidence interval, 0.71-3.43).
  
  
  CONCLUSIONS
  Among people with Lynch syndrome, current smokers have an increased risk of colorectal adenomas. Former smokers have a lower risk than current smokers, but greater risk than never smokers. Individuals with Lynch syndrome should be encouraged to avoid smoking.
authors: Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
authors: Renate M
authors: RM
authors: Winkels
authors: Akke
authors: A
authors: Botma
authors: Fränzel J B
authors: FJ
authors: Van Duijnhoven
authors: Fokko M
authors: FM
authors: Nagengast
authors: Jan H
authors: JH
authors: Kleibeuker
authors: Hans F A
authors: HF
authors: Vasen
authors: Ellen
authors: E
authors: Kampman
mesh_terms: D000236:Adenoma / Q000209:etiology*; D000428:Alcohol Drinking / Q000009:adverse effects; D015179:Colorectal Neoplasms / Q000209:etiology*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000150:complications*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D057566:Self Report; D012907:Smoking / Q000009:adverse effects*