Alcohol consumption (regardless of the type of alcohol) is linked to an increased risk of the most common type of breast cancer in postmenopausal women, according to researchers at the National Cancer Institute, who analyzed data from more than 184,000 women. Women who consumed one to two small drinks a day were 32 percent more likely to develop a hormone-sensitive tumor, and three or more drinks a day raised the risk by 51 per cent. The NCI study lends credence to the theory that alcohol's interference with the metabolism of estrogen raises the risk of cancer.