title: Tobacco and alcohol in relation to male breast cancer: an analysis of the male breast cancer pooling project consortium.
abstract: BACKGROUND
  The etiology of male breast cancer is poorly understood, partly due to its relative rarity. Although tobacco and alcohol exposures are known carcinogens, their association with male breast cancer risk remains ill-defined.
  
  
  METHODS
  The Male Breast Cancer Pooling Project consortium provided 2,378 cases and 51,959 controls for analysis from 10 case-control and 10 cohort studies. Individual participant data were harmonized and pooled. Unconditional logistic regression was used to estimate study design-specific (case-control/cohort) ORs and 95% confidence intervals (CI), which were then combined using fixed-effects meta-analysis.
  
  
  RESULTS
  Cigarette smoking status, smoking pack-years, duration, intensity, and age at initiation were not associated with male breast cancer risk. Relations with cigar and pipe smoking, tobacco chewing, and snuff use were also null. Recent alcohol consumption and average grams of alcohol consumed per day were also not associated with risk; only one subanalysis of very high recent alcohol consumption (>60 g/day) was tentatively associated with male breast cancer (ORunexposed referent = 1.29; 95% CI, 0.97-1.71; OR>0-<7 g/day referent = 1.36; 95% CI, 1.04-1.77). Specific alcoholic beverage types were not associated with male breast cancer. Relations were not altered when stratified by age or body mass index.
  
  
  CONCLUSIONS
  In this analysis of the Male Breast Cancer Pooling Project, we found little evidence that tobacco and alcohol exposures were associated with risk of male breast cancer.
  
  
  CONCLUSIONS
  Tobacco and alcohol do not appear to be carcinogenic for male breast cancer. Future studies should aim to assess these exposures in relation to subtypes of male breast cancer.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland. cook.mich@mail.nih.gov.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Cook
authors.affiliation: Inserm, CESP Center for Research in Epidemiology and Population Health, Environmental Epidemiology of Cancer, Villejuif, France. Université Paris-Sud, UMRS 1018, Villejuif, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Guénel
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, Georgia.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Gapstur
authors.affiliation: Department of Epidemiology, Maastricht University, Maastricht, the Netherlands.
authors.forename: Piet A
authors.initials: PA
authors.lastname: van den Brandt
authors.affiliation: Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Karin B
authors.initials: KB
authors.lastname: Michels
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California.
authors.forename: John T
authors.initials: JT
authors.lastname: Casagrande
authors.affiliation: Division of Genetics and Epidemiology, The Institute of Cancer Research, Sutton, Surrey, United Kingdom.
authors.forename: Rosie
authors.initials: R
authors.lastname: Cooke
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, California.
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Van Den Eeden
authors.affiliation: Department of Oncology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors.forename: Marianne
authors.initials: M
authors.lastname: Ewertz
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland.
authors.forename: Roni T
authors.initials: RT
authors.lastname: Falk
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, Georgia.
authors.forename: Mia M
authors.initials: MM
authors.lastname: Gaudet
authors.affiliation: Department of Surgery, Aretaieion University Hospital, Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Gkiokas
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, California.
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Habel
authors.affiliation: Cancer Prevention Institute of California, Freemont, California. Stanford Cancer Institute, Stanford, California.
authors.forename: Ann W
authors.initials: AW
authors.lastname: Hsing
authors.affiliation: Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Johnson
authors.affiliation: Cancer Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii.
authors.forename: Laurence N
authors.initials: LN
authors.lastname: Kolonel
authors.affiliation: Department of Clinical Science and Community Health, University of Milan, Milan, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Institute of Public Health, University of Copenhagen, Denmark.
authors.forename: Elsebeth
authors.initials: E
authors.lastname: Lynge
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland.
authors.forename: Jay H
authors.initials: JH
authors.lastname: Lubin
authors.affiliation: Section on Environment and Radiation, International Agency for Research on Cancer, Lyon, France.
authors.forename: Valerie A
authors.initials: VA
authors.lastname: McCormack
authors.affiliation: Istituto di Richerche Farmacologiche "Mario Negri," Milan, Italy.
authors.forename: Eva
authors.initials: E
authors.lastname: Negri
authors.affiliation: Department of Oncology, Lund University, Lund, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Olsson
authors.affiliation: Information Management Services, Inc., Rockville, Maryland.
authors.forename: Dominick
authors.initials: D
authors.lastname: Parisi
authors.affiliation: Department of Hygiene, Epidemiology, and Medical Statistics, Athens University Medical School, Athens, Greece.
authors.forename: Eleni Th
authors.initials: ET
authors.lastname: Petridou
authors.affiliation: School of Public Health, Imperial College, London, United Kingdom.
authors.forename: Elio
authors.initials: E
authors.lastname: Riboli
authors.affiliation: Divisions of Preventive Medicine and Aging, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Howard D
authors.initials: HD
authors.lastname: Sesso
authors.affiliation: Division of Genetics and Epidemiology, The Institute of Cancer Research, Sutton, Surrey, United Kingdom. Division of Breast Cancer Research, Institute of Cancer Research, London, United Kingdom.
authors.forename: Anthony
authors.initials: A
authors.lastname: Swerdlow
authors.affiliation: Program in Epidemiology, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: David B
authors.initials: DB
authors.lastname: Thomas
authors.affiliation: Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, Massachusetts. Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Brinton
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology*; D018567:Breast Neoplasms, Male / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D015331:Cohort Studies; D006801:Humans; D008297:Male; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology; D014026:Nicotiana