Alcohol consumption increases risk of breast cancer recurrence, study finds

Marilyn L. Kwan, Ph.D., staff scientist in the Division of Research at Kaiser Permanente, Oakland, Calif., presented detailed results of this study at the CTRC-AACR San Antonio Breast Cancer Symposium, held Dec. 9-13, 2009.

Based on these findings, Kwan suggested, "women previously diagnosed with breast cancer should consider limiting their consumption of alcohol to less than three drinks per week, especially women who are postmenopausal and overweight or obese."

Previous research has shown that consumption of alcohol is associated with an increased risk of breast cancer, but there are limited studies to date about alcohol's role in patient prognosis and survival among those already diagnosed with breast cancer. 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 cohort 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 questionnaire. 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 the study population), 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. Alcohol consumption was not associated with overall mortality.

"Considering the few studies that have addressed alcohol and its influence on breast cancer prognosis, and that the increased risk of recurrence was observed in only some subgroups, our results should be confirmed in other prospective studies. Yet, these results can help women make a more informed decision about lifestyle choices after a diagnosis of breast cancer," said Kwan.