WOMEN who take hormone replacement therapy (HRT) after years on the pill may be more than doubling their risk of breast cancer, writes Roger Dobson.

A study of more than 30,000 women who had gone through the menopause found that those who used HRT but had not been on the pill were 67% more likely to have developed breast tumours than women who had used neither. Those who used both were at 145% greater risk.

While the results are not conclusive, the researchers believe they are important for women who, after the explosion in the use of the pill from the 1960s onwards, are now going through the menopause.

“There appears to be a ‘double whammy’ effect,” said Eiliv Lund, a professor at the Institute of Community Medicine at Tromso University, Norway, who led the study. “The increased risk we found was substantial and has significant implications because of the increasing number of women who used the contraceptive pill who will be coming to the age when they will be using HRT.”

An estimated 1.7m women in Britain use HRT, finding it reduces menopausal effects such as hot flushes, headaches and nausea, and also boosts energy.

Previous research has suggested separately that HRT and the oral contraceptive may increase the risk of breast cancer, which kills more than 12,000 women a year in Britain.

Lund and his team studied 30,118 Norwegian women and found that the highest proportion of cancer cases was in those who had used the pill and were still using HRT. The study suggests, however, that the increased risk may fall off substantially after women stop using the hormone therapy.

Dr Sarah Cant, senior policy officer at the Breakthrough Breast Cancer charity, said: “This is the first large-scale, long-term study to suggest that taking both in your lifetime could increase the risk further.”

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