Alcohol and breast cancer. Where are we now where do we go from here?

Abstract

The alcohol-breast cancer hypothesis is important because (1) breast cancer is a major source of morbidity and mortality, (2) alcohol consumption is common, and (3) drinking is modifiable. Reports from more than 50 epidemiologic investigations of this hypothesis have now appeared. A recent metaanalysis of these studies indicates both a modest positive association between alcohol and breast cancer (an approximate 25% increase in risk with daily intake of the equivalent of two drinks) and a doseresponse relation. Data suggest that risk increases with consumption of alcohol in general, regardless of beverage type. Several factors, including age, weight, and estrogen usage, have been shown to modify this relation in some studies. The authors discuss a series of methodologic issues in the study of alcohol and breast cancer. These include error in alcohol assessment, difficulties in evaluating small relative risks, and the potential for confounding. Several biologic mechanisms could account for an alcohol-breast cancer relation, with increasing attention being paid to a possible mediating effect of reproductive steroid hormones. Animal studies are a relatively recent development in this area; results have been mixed. Incorporation of more refined temporal, quantitative, and qualitative indicators of alcohol exposure in future epidemiologic studies would be valuable, as would further exploration of the endocrine and other metabolic effects of moderate alcohol consumption. The alcohol-breast cancer hypothesis remains intriguing, but causality has not been established. Cancer 1994; 74:llOl-10.

Alcohol metabolism, alcohol intake, and breast cancer risk: a sister-set analysis using the Breast Cancer Family Registry

“…per day [1][2][3][4][5][6][7][8][9][10][11][12]. It is more difficult to rule out confounding and bias as alternative explanations for associations of low magnitude, even if the findings have been consistently replicated [13].…”

Perspectives on the chemical etiology of breast cancer.

“…The relationship of alcohol consumption to risk of breast cancer has been studied for many decades (50,51). Low consumption levels (1-3 drinks per week) were not found to increase risk of breast cancer (52).…”

Hormone replacement therapy and breast cancer.

“…Since then the association has been examined in more than 50 epidemiological studies (Schatzkin & Longnecker 1994). A meta-analysis of 28 case control and 10 cohort studies indicated a doseresponse association between the amount of alcohol consumed and the risk of breast cancer (Longnecker 1994).…”