Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease.
Hamajima N., Hirose K., Tajima K., Rohan T., Calle EE., Heath CW., Coates RJ., Liff JM., Talamini R., Chantarakul N., Koetsawang S., Rachawat D., Morabia A., Schuman L., Stewart W., Szklo M., Bain C., Schofield F., Siskind V., Band P., Coldman AJ., Gallagher RP., Hislop TG., Yang P., Kolonel LM., Nomura AM., Hu J., Johnson KC., Mao Y., De Sanjosé S., Lee N., Marchbanks P., Ory HW., Peterson HB., Wilson HG., Wingo PA., Ebeling K., Kunde D., Nishan P., Hopper JL., Colditz G., Gajalanski V., Martin N., Pardthaisong T., Silpisornkosol S., Theetranont C., Boosiri B., Chutivongse S., Jimakorn P., Virutamasen P., Wongsrichanalai C., Ewertz M., Adami HO., Bergkvist L., Magnusson C., Persson I., Chang-Claude J., Paul C., Skegg DC., Spears GF., Boyle P., Evstifeeva T., Daling JR., Hutchinson WB., Malone K., Noonan EA., Stanford JL., Thomas DB., Weiss NS., White E., Andrieu N., Brêmond A., Clavel F., Gairard B., Lansac J., Piana L., Renaud R., Izquierdo A., Viladiu P., Cuevas HR., Ontiveros P., Palet A., Salazar SB., Aristizabel N., Cuadros A., Tryggvadottir L., Tulinius H., Bachelot A., Lê MG., Peto J., Franceschi S., Lubin F., Modan B., Ron E., Wax Y., Friedman GD., Hiatt RA., Levi F., Bishop T., Kosmelj K., Primic-Zakelj M., Ravnihar B., Stare J., Beeson WL., Fraser G., Bullbrook RD., Cuzick J., Duffy SW., Fentiman IS., Hayward JL., Wang DY., McMichael AJ., McPherson K., Hanson RL., Leske MC., Mahoney MC., Nasca PC., Varma AO., Weinstein AL., Moller TR., Olsson H., Ranstam J., Goldbohm RA., van den Brandt PA., Apelo RA., Baens J., de la Cruz JR., Javier B., Lacaya LB., Ngelangel CA., La Vecchia C., Negri E., Marubini E., Ferraroni M., Gerber M., Richardson S., Segala C., Gatei D., Kenya P., Kungu A., Mati JG., Brinton LA., Hoover R., Schairer C., Spirtas R., Lee HP., Rookus MA., van Leeuwen FE., Schoenberg JA., McCredie M., Gammon MD., Clarke EA., Jones L., Neil A., Vessey M., Yeates D., Appleby P., Banks E., Beral V., Bull D., Crossley B., Goodill A., Green J., Hermon C., Key T., Langston N., Lewis C., Reeves G., Collins R., Doll R., Peto R., Mabuchi K., Preston D., Hannaford P., Kay C., Rosero-Bixby L., Gao YT., Jin F., Yuan JM., Wei HY., Yun T., Zhiheng C., Berry G., Cooper Booth J., Jelihovsky T., MacLennan R., Shearman R., Wang QS., Baines CJ., Miller AB., Wall C., Lund E., Stalsberg H., Shu XO., Zheng W., Katsouyanni K., Trichopoulou A., Trichopoulos D., Dabancens A., Martinez L., Molina R., Salas O., Alexander FE., Anderson K., Folsom AR., Hulka BS., Bernstein L., Enger S., Haile RW., Paganini-Hill A., Pike MC., Ross RK., Ursin G., Yu MC., Longnecker MP., Newcomb P., Bergkvist L., Kalache A., Farley TM., Holck S., Meirik O., Collaborative Group on Hormonal Factors in Breast Cancer None.
Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.