Alcohol consumption has been associated with increased breast cancer risk in most studies that have examined its effects.
However, relatively few studies have examined the influence of alcohol consumption on survival after a diagnosis of breast cancer and they have produced inconsistent results:
- A 2012 German prospective study of 2,706 postmenopausal breast cancer patients was designed to investigate the associations between alcohol consumption and survival and recurrence. Consumption was divided into four levels: <0.5 g/day, 0.5 to <6 g/day, 6 to <12 g/day, and ≥12 g/day. Alcohol intake of ≥ 12 g/day was found to be associated with 1.7 times the risk of breast cancer-specific death compared to < 0.5 g/day. However, the results were no longer statistically significant when only Stage I-IIIa patients were included in the analysis. Body mass index (BMI), use of hormone replacement therapy (HRT), and estrogen receptor (ER) status did not influence the risk of death. Furthermore, no association with breast cancer recurrence was observed. The authors concluded that consumption of more than 12 g alcohol (equivalent to approximately one alcoholic drink) per day is associated with increased risk of breast cancer-specific death but not with breast cancer recurrence.
- A 2012 Swedish study was also designed to investigate the influence of alcohol consumption on survival among breast cancer patients. The study included 3,146 women with invasive breast cancer in the Swedish Mammography Cohort. No statistically significant association was found between alcohol intake and breast cancer-specific survival. Women who consumed 10 g (approximately 0.75 to 1 drink) or more of alcohol per day had 1.36 times the risk of breast cancer-specific death compared to non-drinkers, but this result did not reach statistical significance. On the other hand, alcohol consumption was significantly associated with reduced non-breast cancer deaths. Women who consumed 3.4 to 9.9 g per day of alcohol had a 33% lower risk of death compared with non-drinkers. The authors concluded that alcohol consumption up to approximately one small drink per day does not negatively influence breast cancer-specific survival and a half drink per day is associated with a decreased risk of death from other causes.
- A 2010 California prospective study was designed to investigate the association between alcohol consumption in women with early-stage breast cancer and breast cancer recurrence and mortality. The study included 1,897 women primarily from the Kaiser Permanente Northern California Cancer Registry. Nine hundred and fifty-eight of the women (51%) were considered to be alcohol drinkers (> 0.5 g/day of alcohol); the majority drank wine (89%). Compared with abstinence from alcohol, drinking at least 6 g/day of alcohol was found to be associated with a 1.35 times the risk of breast cancer recurrence and 1.51 times the risk of death due to breast cancer. The increased risk of recurrence attributable to alcohol was higher among postmenopausal, as well as overweight and obese women. Alcohol intake appeared to be associated with a decreased risk of death from causes other than breast cancer. The authors concluded that consuming three to four alcoholic drinks or more per week after a breast cancer diagnosis may increase risk of breast cancer recurrence, particularly among postmenopausal and overweight/obese women. However, the data also suggests a cardioprotective effect of moderate alcohol consumption.
- Another 2010 U.S. study examined alcohol intake (beer, wine, spirits, and total) in 3,088 women previously diagnosed and treated for breast cancer. Alcohol intake was found to be significantly associated with higher education and physical activity levels. Neither light alcohol intake nor obesity was found to be significantly associated with breast cancer recurrence, but moderate alcohol intake was protective against death from any cause. The authors concluded that light alcohol intake, regardless of body weight, did not increase the risk of breast cancer recurrence or all-cause mortality in this cohort of middle-aged women previously diagnosed with breast cancer. Alcohol intake was associated with other favorable prognostic indicators, which may explain its apparent protective effect in nonobese women.
Latest research finds alcohol intake before diagnosis is associated with recurrence
The study referenced at the beginning of this news article was designed to investigate the association between pre-diagnostic alcohol consumption and breast cancer recurrence and death. The study included 1,052 women diagnosed with early breast cancer in a prospective cohort of 29,875 women. The women were followed for a median of six years after diagnosis.
Alcohol consumption before diagnosis was found to be associated with a modest but significant increase in breast cancer recurrence. The results held both when using baseline measures of alcohol intake and cumulative lifetime alcohol intake. Results for breast cancer-specific death were also suggestive of a higher risk for alcohol consumption but were not statistically significant. The authors conclude that, in addition to being a risk factor for the development of breast cancer, a high pre-diagnostic alcohol intake appears to have an unfavorable effect on the course of the disease. The findings were not associated with specific tumor types.
Please see our article on whether to drink red wine for more information.