Submitted to: Journal of the National Cancer Institute
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2001
Publication Date: 5/2/2001
Citation: Dorgan, J., Judd, J.T., Baer, D.J., Clevidence, B.A. 2001. Serum hormones potentially mediate the alcohol-breast cancer association in postmenopausal women. Journal of the National Cancer Institute. 93:710-715.
Interpretive Summary: Moderate consumption of alcohol has been related to breast cancer risk in epidemiological studies. There is disagreement on the importance of alcohol in breast cancer risk at low levels of intake. In a controlled diet study with 51 postmenopausal women not using hormone replacement therapy, alcohol consumption equivalent to one to two drinks of alcoholic beverage per day was found to increase levels of two important steroid hormones that have been found in epidemiological studies to be elevated in women at increased risk of breast cancer. This study provides an important link between the clinical and epidemiological data on the diet- hormone theory of breast cancer risk, and should be of interest to research scientist, medical professionals, and consumers of alcohol who have elevations of other risk factors for breast cancer.
Technical Abstract: Background: Alcohol ingestion is positively related to breast cancer risk in most epidemiologic studies, but results are heterogeneous at lower levels of intake and the causal nature of the association remains controversial. We performed a controlled feeding study to evaluate the effect of chronic moderate alcohol ingestion on serum levels of hormones that have been related to an increased risk of breast cancer. Methods: Participants included 51 healthy postmenopausal women not using hormone replacement therapy. Each participant consumed 15 gm alcohol/day, 30 gm alcohol/day, or a placebo beverage during one of three 8-week dietary periods. The order of assignment to the three alcohol levels was random. Each dietary period was preceded by a 2-5 week washout period. All food and beverages were supplied by the study during the dietary periods, and energy intake was adjusted to keep body weight constant. Estradiol, estrone, estrone sulfate, testosterone, androstenedione, progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate, and androstenediol were measured in serum collected at the end of each dietary period. Results: When consuming 15 gm and 30 gm alcohol/day, respectively, participants' estrone sulfate concentrations increased by 7.5% (95% confidence interval (CI) = -0.3, 15.9) and 10.7% (95% CI = 2.7, 19.3), and their DHEAS concentrations increased by 5.1% (95% CI = 1.4, 9.0) and 7.5% (95% CI = 3.7, 11.5). None of the other hormones measured changed significantly when women consumed alcohol. Conclusions: Results from this study suggest a mechanism by which consumption of 1-2 alcoholic drinks/day by postmenopausal women could increase their risk of breast cancer.