Moderate to heavy alcohol consumption may trigger increased risk of breast cancer recurrence.
Post-menopausal or overweight women may be most susceptible to the effects of alcohol on recurrence, said the study conducted by Marilyn L. Kwan, Kaiser Permanente research scientist.
"Women previously diagnosed with breast cancer should consider limiting their consumption of alcohol to less than three drinks per week," says Kwan.
Kwan and colleagues examined the effects of alcohol on cancer recurrence and mortality in the Life After Cancer Epidemiology (LACE) Study.
LACE is a prospective study of 1,897 early-stage breast cancer survivors diagnosed with early-stage invasive breast cancer between 1997 and 2000.
The researchers recruited participants from the Kaiser Permanente Northern California Cancer Registry. Information on wine, beer and liquor consumption was documented via questionnaires.
Each year, participants also filled out information on health outcomes, including recurrence of breast cancer, which was then verified by their medical records.
After eight years of follow-up, Kwan and colleagues found 349 breast cancer recurrences and 332 deaths.
Among drinkers (50 percent of participants), wine was the most popular choice of alcohol (90 percent), followed by liquor (43 percent) then beer (36 percent). Increased risk of cancer recurrence was most predominant among those who consumed two or more glasses of wine per day.
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, says a Kaiser Permanente release.