Anastrozole found to be more effective than tamoxifen and raloxifene  - the two preventative drugs made accessable to thousands on NHS this year

A breast cancer drug that protects women more effectively than either of the current treatments should be made freely available on the NHS, experts have urged.

In trials, the drug anastrozole was found to reduce the likelihood of breast cancer in post-menopausal women who were already at high risk by 53 per cent, making it more effective than tamoxifen and raloxifene  - the two preventative drugs made available to thousands of women on the NHS earlier this year.

The study led by Queen Mary, University of London, and published in The Lancet, looked at almost 4,000 postmenopausal women, half of whom were given anastrozole daily for five years, while the other half took a placebo.

85 women in the placebo group developed breast cancer, compared to just 40 in the anastrozole group.

Tamoxifen and raloxifene reduce risk by around 40 per cent.

Professor Jack Cuzick, lead researcher and head of Queen Mary’s Centre for Cancer Prevention, said that anastrozole should now be the “drug of choice” for postmenopausal women with a family history of breast cancer, or other risk factors.

“This class of drugs is more effective than previous drugs and crucially, it has fewer side effects…in this study, the reported side effects were only slightly higher than in the placebo arm,” he said.

“Our priority now is ensuring that as many women as possible can benefit from these new findings,” Professor Cuzick added. “We strongly urge the National Institute for Health and Care Excellence (Nice) to consider adding anastrozole to their recommended drugs for women who are predisposed to developing breast cancer. By including this drug in their clinical guidelines, more women will benefit from this important advancement in preventive medicine.”

Professor Mark Baker, director of the Centre for Clinical Practice at Nice, said: "We will certainly consider this research - along with all other available evidence - when the Nice guideline on familial breast cancer is next updated.”