TWO cups or more of coffee a day could stop breast cancer recurring in recovering patients, according to new research.
Swedish experts examined the possible link between women drinking several cups of coffee and hormone drug tamoxifen, which is designed to prevent the cancer coming back.
Breast cancer is the most common cancer to affect women in Sweden, which has one of the highest rates of coffee consumption in Europe, with an average 3.4 cups a day per person.
Helena Jernström, associate professor of experimental oncology at Lund University, said: “We would like to know more about how lifestyle can interact with breast cancer treatment.
“This is the first study, as far as we know, looking at the combination of this drug and coffee. We hope that someone else will now help confirm the research.”
A previous study found that coffee reduced the risk of one type of aggressive breast cancer tumour, but similar work was needed on the most common type, known as oestrogen receptor-positive (ER+), where cancer cells need the female hormone oestrogen to grow. This is usually treated, in part, with hormone therapy to block the oestrogen and prevent the cells returning.
Lund scientists studied 634 patients over six years from 2002 to 2008. About half of the patients were being treated with tamoxifen, which is commonly used after breast cancer surgery. In addition to basic health information and lifestyle factors such as smoking and alcohol consumption, patients ranked their coffee drinking from zero to eight or more cups of coffee a day.
Patients ranged in age from 25 to 99 and the proportion of the ER+ tumours decreased with higher amounts of coffee consumption.
Tamoxifen blocks oestrogen receptors to prevent the return of the cancer, but how the coffee interacts with that medication is not known. Researchers said it could be making the drug more efficient.
The study stated that for 310 women who had ER+ tumours and were given tamoxifen, moderate to high coffee consumption was linked to a lower risk for the cancer returning early.
Even after other factors were considered, the coffee was still found to make a significant difference.
Cancer charities cautioned against making assumptions about coffee as a cure, or prevention, based on one study.
James Jopling, director for Scotland at Breakthrough Breast Cancer, said: “Based on this research alone we wouldn’t advise that women taking tamoxifen increase their coffee intake.”
Henry Scowcroft, science information manager at Cancer Research UK, said: “It in no way means women with breast cancer should drink coffee to try to prevent their cancer returning.”