title: Alcohol drinking and non-Hodgkin lymphoma risk: a systematic review and a meta-analysis.
abstract: BACKGROUND
  Whether an association between alcohol drinking and non-Hodgkin lymphoma (NHL) risk exists is an open question. In order to provide quantification of the issue, we carried out a meta-analysis of published data.
  
  
  METHODS
  We identified 21 case-control and 8 cohort studies, including a total of 18,759 NHL cases. We derived meta-analytic estimates using random-effects models, taking into account correlation between estimates.
  
  
  RESULTS
  The overall relative risk (RR) of NHL for drinkers versus non-drinkers was 0.85 [95% confidence interval (CI) 0.79-0.91]. Compared with non-drinkers, the pooled RRs were 0.88 for light (≤1 drink per day), 0.87 for moderate (1 to <4 drinks per day), and 0.84 for heavy (≥4 drinks per day) alcohol drinking. There was no association for light drinkers in cohort studies, whereas for moderate and heavy drinkers, the RRs were similar in case-control (0.85 for moderate, 0.92 for heavy) and cohort (0.89 for moderate, 0.79 for heavy) studies. The inverse relation with alcohol consumption (drinkers versus non-drinkers) was similar in men (RR = 0.83) and women (RR = 0.86), but apparently stronger in studies from Asia (RR = 0.69) than other world areas (RR = 0.88).
  
  
  CONCLUSIONS
  This meta-analysis provides quantitative evidence of a favourable role of alcohol drinking on NHL risk, though the lack of a biological explanation suggests caution in the interpretation of results.
authors.affiliation: Department of Epidemiology, Mario Negri Institute for Pharmacological Research, Milan.
authors.forename: I
authors.initials: I
authors.lastname: Tramacere
authors.affiliation: Department of Epidemiology, Mario Negri Institute for Pharmacological Research, Milan. Electronic address: claudio.pelucchi@marionegri.it.
authors.forename: C
authors.initials: C
authors.lastname: Pelucchi
authors.affiliation: Department of Epidemiology, Mario Negri Institute for Pharmacological Research, Milan.
authors.forename: M
authors.initials: M
authors.lastname: Bonifazi
authors.affiliation: Department of Statistics, University of Milano-Bicocca, Milan; Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan.
authors.forename: V
authors.initials: V
authors.lastname: Bagnardi
authors.affiliation: Department of Statistics, University of Milano-Bicocca, Milan; Department of Clinical Medicine and Prevention, Centre of Biostatistics for Clinical Epidemiology, University of Milano-Bicocca, Monza, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rota
authors.affiliation: Department of Statistics, University of Milano-Bicocca, Milan; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Bellocco
authors.affiliation: Department of Statistics, University of Milano-Bicocca, Milan.
authors.forename: L
authors.initials: L
authors.lastname: Scotti
authors.affiliation: International Agency for Research on Cancer, Lyon, France; Digestive Disease Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran; The Tisch Cancer Institute, Mount Sinai School of Medicine, New York, USA.
authors.forename: F
authors.initials: F
authors.lastname: Islami
authors.affiliation: Department of Statistics, University of Milano-Bicocca, Milan.
authors.forename: G
authors.initials: G
authors.lastname: Corrao
authors.affiliation: The Tisch Cancer Institute, Mount Sinai School of Medicine, New York, USA; International Prevention Research Institute, Lyon, France.
authors.forename: P
authors.initials: P
authors.lastname: Boffetta
authors.affiliation: Department of Epidemiology, Mario Negri Institute for Pharmacological Research, Milan; Department of Occupational Health, University of Milano, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Department of Epidemiology, Mario Negri Institute for Pharmacological Research, Milan.
authors.forename: E
authors.initials: E
authors.lastname: Negri
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D012307:Risk Factors