||Ali AM, Schmidt MK, Bolla M, Wang Q, Gago-Dominguez M, Esteban Castelao J, Carracedo A, MuÃ±oz GarzÃ³n V, Bojesen SE, Nordestgaard BG, Flyger H, Chang-Claude J, Vrieling A, Rudolph A, Seibold P, Nevanlinna H, Muranen TA, Aaltonen K, Blomqvist C, Matsuo K, Ito H, Iwata H, Horio A, John EM, Sherman M, Lissowska J, Figueroa JD, Garcia-Closas M, Anton-Culver H, Shah M, Hopper JL, Trichopoulou A, Bueno-de-Mesquita HB, Krogh V, Weiderpass E, Andersson A, Clavel-Chapelon F, Dossus L, Fagherazzi G, Peeters PH, Olsen A, Wishart GC, Easton DF, Borgquist S, Overvad K, Barricarte A, GonzÃ¡lez CA, Sanchez MJ, Amiano Etxezarreta P, Riboli E, Key TJ, Pharoah PD
||Background Evidence for the association of alcohol consumption with prognosis after a diagnosis of breast cancer has been inconsistent. We have reviewed and summarised the published evidence and evaluated the association using individual patient data from multiple case cohorts. Materials and Methods A MEDLINE search to identify studies published up to January 2013 was performed. We combined published estimates for survival time in "moderate drinkers" versus non-drinkers. An analysis of individual participant data using Cox regression was carried out using data from eleven case cohorts. Results We identified eleven published studies suitable for inclusion in the meta-analysis. Moderate post-diagnosis alcohol consumption was not associated with overall survival (HR = 0.95, 95% CI 0.85-1.05), but there was some evidence of better survival associated with pre-diagnosis consumption (HR = 0.80, 95% CI 0.73-0.88). Individual data on alcohol consumption for 29,239 cases with 4,839 deaths were available from the eleven case cohorts, all of which had data on ER status. For women with ER-positive disease there was little evidence that pre- or post-diagnosis alcohol consumption is associated with breast cancer-specific mortality, with some evidence of a reduction in all-cause mortality. Based on a single study, moderate post-diagnosis alcohol intake was associated with a small reduction in breast cancer-specific mortality in women with ER-negative disease. There was no association for pre-diagnosis intake in women with ER-negative disease. Impact Considering the totality of the evidence, moderate post-diagnosis alcohol consumption is unlikely to have a major adverse effect on survival of women with breast cancer.