After eight years of follow-up, Kwan and colleagues found 349 breast cancer recurrences and 332 deaths from cancer and other causes. Among drinkers (50 percent of the study population), wine was the most popular choice of alcohol (90 percent), followed by liquor (43 percent) then beer (36 percent).

The increased risk of recurrence appeared to be greater among participants who were postmenopausal and overweight or obese, and was present regardless of type of alcohol. Alcohol consumption was not associated with overall mortality.

"These results can help women make more informed decisions about lifestyle choices after a diagnosis of breast cancer," Kwan said. She added that these findings should be confirmed with more research because few studies have addressed the influence of alcohol on breast cancer prognosis, and the increased risk of recurrence was observed in only some subgroups.

Additional researchers on the study include Erin Weltzien, Emily Tam, Adrienne Castillo, Lawrence Kushi and Bette Caan, all with the Kaiser Permanente Division of Research; and Carol Sweeney, with the division of clinical epidemiology and department of internal medicine at the University of Utah. Funding for the study was provided by the National Cancer Institute.

Source: Kaiser Permanente