Exploring the relation of alcohol consumption to risk of breast cancer.
There are lingering questions regarding the relation between alcohol consumption and breast cancer risk in women. The authors performed a meta-analysis of epidemiologic studies carried out through 1999 to examine the dose-response relation and to assess whether effect estimates differed according to various study characteristics. Overall, there was a monotonic increase in the relative risk of breast cancer with alcohol consumption, but the magnitude of the effect was small; in comparison with nondrinkers, women averaging 12 g/day of alcohol consumption (approximately one typical drink) had a relative risk of 1.10 (95% confidence interval (CI): 1.06, 1.14). Estimates of relative risk were 7% greater in hospital-based case-control studies than in cohort studies or community-based case-control studies, 3% greater in studies published before 1990 than in studies published later, and 5% greater in studies conducted outside of the United States than in US studies. The findings of five US cohort studies published since 1990 yielded a relative risk of 1.06 (95% CI: 1.00, 1.11) for consumers of 12 g/day, as compared with nondrinkers. Cohort studies with less than 10 years of follow-up gave estimates 11% higher than cohort studies with longer follow-up periods. No meaningful difference was seen by menopausal status or type of beverage consumed.
Ellison
R C
RC
Section of Preventive Medicine and Epidemiology, Evans Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA. ellison@bu.edu
Zhang
Y
Y
McLennan
C E
CE
Rothman
K J
KJ
D000428:Alcohol Drinking / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D012307:Risk Factors