The Relationship Between Alcohol and Breast Cancer Differs by Tumor Receptor Status

The association between alcohol intake and breast cancer may differ by the positive or negative estrogen-receptor (ER) and progesterone-receptor (PR) status of breast tumors. Researchers investigated this possibility using data from 51,847 postmenopausal participants in a population-based Swedish study. During approximately 8 years of follow-up, 1188 women with breast cancer with known ER and PR status were identified.

• In analyses adjusted for potential confounders (e.g., age, family history of breast cancer, body mass index), drinking approximately >=1 drinks per day significantly increased the risk of developing ER positive tumors—regardless of PR status—in women who had used postmenopausal hormones.
• Drinking also increased risk, but at a nonsignificant level, among women who did not use the hormones.
• Alcohol use did not significantly increase the risk of developing ER negative tumors.

Comments:

This study found that alcohol increased the risk of ER positive, but not negative, tumors—a finding that supports some previous research but contradicts other reports. Although these researchers examined postmenopausal hormone use and adjusted analyses for potential confounders, they did not account for folate intake, which can also modify the association between alcohol and breast cancer. Overall, the scientific data suggest an increased risk of breast cancer for women who consume alcohol, but the mechanisms for and modifiers of this risk remain unclear.

R. Curtis Ellison, MD

Reference:

Suzuki R, Ye W, Rylander-Rudqvist T, et al. Alcohol and postmenopausal breast cancer risk defined by estrogen and progesterone receptor status: a prospective cohort study. J Natl Cancer Inst. 2005;97(21):1601–1608.