Serum hormones and the alcohol-breast cancer association in postmenopausal women.
BACKGROUND
Alcohol ingestion is associated with an increased risk of breast cancer in most epidemiologic studies. Results, however, are heterogeneous at lower levels of alcohol intake, and a biologic mechanism for the association has not been clearly identified. To determine whether alcohol consumption by postmenopausal women elevates serum levels of hormones associated with an increased risk of breast cancer, we performed a controlled feeding study.


METHODS
Participants were 51 healthy postmenopausal women not using hormone replacement therapy. Each participant rotated through three 8-week dietary periods in which she consumed 15 or 30 g of alcohol per day or an alcohol-free placebo beverage. The order of assignment to the three alcohol levels was random. During the dietary periods, all food and beverages were supplied by the study, and energy intake was adjusted to keep body weight constant. Levels of estradiol, estrone, estrone sulfate, testosterone, androstenedione, progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), and androstenediol were measured by radioimmunoassays in serum collected at the end of each dietary period. All statistical tests are two-sided.


RESULTS
When women consumed 15 or 30 g of alcohol per day, respectively, estrone sulfate concentrations increased by 7.5% (95% confidence interval [CI] = -0.3% to 15.9%; P =.06) and 10.7% (95% CI = 2.7% to 19.3%; P =.009) and DHEAS concentrations increased by 5.1% (95% CI = 1.4% to 9.0%; P =.008) and 7.5% (95% CI = 3.7% to 11.5%; P<.001) relative to levels when women consumed placebo. None of the other hormones measured changed statistically significantly when women consumed alcohol.


CONCLUSIONS
Results suggest a possible mechanism by which consumption of one or two alcoholic drinks per day by postmenopausal women could increase their risk of breast cancer.
Dorgan
J F
JF
Fox Chase Cancer Center, Philadelphia, PA 19111, USA. JF_Dorgan@fccc.edu
Baer
D J
DJ
Albert
P S
PS
Judd
J T
JT
Brown
E D
ED
Corle
D K
DK
Campbell
W S
WS
Hartman
T J
TJ
Tejpar
A A
AA
Clevidence
B A
BA
Giffen
C A
CA
Chandler
D W
DW
Stanczyk
F Z
FZ
Taylor
P R
PR
D000368:Aged; D001943:Breast Neoplasms / Q000139:chemically induced*; D003687:Dehydroepiandrosterone / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D015914:Estrogen Replacement Therapy; D000431:Ethanol / Q000009:adverse effects*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D012738:Sex Hormone-Binding Globulin / Q000032:analysis
D012739:Gonadal Steroid Hormones; D012738:Sex Hormone-Binding Globulin; D000431:Ethanol; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate