Coffee may help to reduce the risk of breast cancer recurring in women who are taking the commonly used drug, Tamoxifen, a new study indicates.

Over 2,000 women are newly diagnosed with breast cancer every year in Ireland and many of these are given the hormone therapy, Tamoxifen, for around five years. According to the Irish Cancer Society, it significantly reduces the risk of the cancer coming back and improves overall survival in all age groups.

Swedish researchers followed the progress of over 600 women with breast cancer for an average of five years. Half of the women were taking Tamoxifen.

The study found that those taking the drug, who also consumed two or more cups of coffee per day, had less than half the rate of disease recurrence compared to those taking the drug, but only consuming one cup of coffee or less per day.

"One theory we are working with is that coffee ‘activates' Tamoxifen and makes it more efficient," the researchers from Lund University said.

In previous research, they have found a link between coffee consumption and a reduced risk of developing some forms of breast cancer. Caffeine has also previously been shown to prevent the growth of cancer cells.

The team said that more research in this area is needed.

Details of their findings are published in the journal, Cancer Causes & Control.