Association of Daily Alcohol Intake, Volumetric Breast Density, and Breast Cancer Risk.

Area of Science:

• Oncology
• Epidemiology
• Radiology

Background:

• High alcohol consumption is a known risk factor for breast cancer (BC).
• Increased breast density is also associated with higher BC risk.
• The interrelationship between alcohol intake and breast density in BC risk remains unclear.

Purpose of the Study:

• To investigate whether volumetric breast density modifies or mediates the association between alcohol consumption and breast cancer risk.
• To quantify the potential mediating role of dense breast volume in the alcohol-BC pathway.

Main Methods:

• Case-control study design using screening mammograms from BC cases and matched controls.
• Logistic regression analysis adjusted for age, BMI, and menopausal status.
• Mediation analysis quantified the proportion of the alcohol-BC association explained by dense breast volume.

Main Results:

• Alcohol consumption was significantly associated with increased BC risk (Ptrend = .004).
• Both volumetric percent density (OR = 1.45 per SD) and dense volume (OR = 1.30) were associated with higher BC risk.
• Breast density did not significantly modify the alcohol-BC association (P > .10).
• Dense breast volume mediated 25.0% (P = .01) of the alcohol-BC association.

Conclusions:

• Alcohol intake may increase breast cancer risk, in part, by increasing the volume of dense fibroglandular tissue.
• Dense breast volume acts as a significant mediator in the pathway between alcohol consumption and breast cancer.
• Findings suggest a potential biological mechanism linking alcohol and breast cancer through changes in breast tissue composition.