Interactions between intakes of alcohol and postmenopausal hormones on risk of breast cancer

Alcohol and postmenopausal hormone use are well‐established modifiable risk factors for breast cancer. Alcohol may decrease the metabolic clearance of estradiol, whereby the risk of breast cancer associated with hormone use may depend on blood alcohol levels. The objective is to determine whether alcohol interacts with hormone use on risk of breast cancer. The 5,035 postmenopausal women who participated in the Copenhagen City Heart Study were asked about their alcohol intake and hormone use at baseline in 1981–1983 and were followed until 2002 in the Danish cancer registry, with