Tobacco and alcohol in relation to male breast cancer: an analysis of the male breast cancer pooling project consortium.
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland. cook.mich@mail.nih.gov.
- Inserm, CESP Center for Research in Epidemiology and Population Health, Environmental Epidemiology of Cancer, Villejuif, France. Université Paris-Sud, UMRS 1018, Villejuif, France.
- Epidemiology Research Program, American Cancer Society, Atlanta, Georgia.
- Department of Epidemiology, Maastricht University, Maastricht, the Netherlands.
- Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
- Department of Preventive Medicine, University of Southern California, Los Angeles, California.
- Division of Genetics and Epidemiology, The Institute of Cancer Research, Sutton, Surrey, United Kingdom.
- Division of Research, Kaiser Permanente Northern California, Oakland, California.
- Department of Oncology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland.
- Department of Surgery, Aretaieion University Hospital, Athens, Greece.
- Cancer Prevention Institute of California, Freemont, California. Stanford Cancer Institute, Stanford, California.
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
- Cancer Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii.
- Department of Clinical Science and Community Health, University of Milan, Milan, Italy.
- Institute of Public Health, University of Copenhagen, Denmark.
- Section on Environment and Radiation, International Agency for Research on Cancer, Lyon, France.
- Istituto di Richerche Farmacologiche "Mario Negri," Milan, Italy.
- Department of Oncology, Lund University, Lund, Sweden.
- Information Management Services, Inc., Rockville, Maryland.
- Department of Hygiene, Epidemiology, and Medical Statistics, Athens University Medical School, Athens, Greece.
- School of Public Health, Imperial College, London, United Kingdom.
- Divisions of Preventive Medicine and Aging, Brigham and Women's Hospital, Boston, Massachusetts.
- 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.
- Program in Epidemiology, Fred Hutchinson Cancer Research Center, Seattle, Washington.
- 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.
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.
IMPACT: 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.