Study summary: The current case-control study was designed to examine the relationship between alcohol consumption and the risk of the most hormonally-responsive breast cancer types (i.e., lobular or hormone receptor positive breast cancers). The study included 975 women 65 to 79 years of age diagnosed with invasive breast cancer during 1997–1999 in Washington State, as well as 1,007 controls. Ever-use of alcohol over the past 20 years was found to be associated with a 1.3-fold [95% confidence interval (CI), 1.0–1.5] increased risk of breast cancer, although this increase was mostly accounted for by women who drank at least 30.0 g per day of alcohol [OR, 1.7; CI: 1.1–2.6]. Ever-use of alcohol also was found to be associated with a 1.8-fold (CI: 1.3–2.5) increased risk of lobular cancer compared to a 1.2-fold (CI: 0.9–1.4) increased risk of ductal cancer. Ever-users of alcohol had an increase in risk of ER+/PR+ tumors (OR, 1.3; CI: 1.1–1.7), but no impact was observed for their risks of ER-/PR- or ER+/PR- breast cancer. The authors conclude that alcohol use appears to be more strongly associated with lobular and hormone receptor-positive cancers than it is with other types of breast cancer.