The drug extends the current five years women can be treated

The team at Manchester's Christie Hospital showed femara (letrozole) reduces the likelihood of a woman dying by 39%.

Currently women with breast cancer undergo standard tamoxifen treatment, which must stop after five years, when the disease is likely to recur.

The trial showed femara reduced the chance of the cancer recurring by 42%.

Researchers have shown that currently more than a third of sufferers will experience a relapse after surgery, with half of those relapses happening after the five years of standard tamoxifen treatment.

The licence is now through and the drug can be prescribed Research spokeswoman

Femara can be prescribed after the standard treatment finishes and also reduces the risk of the cancer spreading by 39%.

Dr Paul Ellis, leading cancer specialist and research spokesman, said: "These results and the improved survival benefits are exciting for both patients and doctors."

The results were shown after an international breast cancer study of more than 5,000 women, with the Christie Hospital one of the main UK research centres.

A spokeswoman said the study began in about October 2001 and should have run for five years.

1,000 deaths

"However, because the results were so positive, it was halted at the two year mark to allow women to go on the drug," she said.

"The licence is now through a year later and the drug can be prescribed."

Femara is now being made available to women with breast cancer who have undergone the standard five year tamoxifen treatment.

"This is a significant and welcome step forward for post-menopausal women who have finished their tamoxifen treatment for early breast cancer but are naturally concerned about recurrence," said Antonia Bunnin, campaigns director of charity Breakthrough Breast Cancer.

Samia al Qadhi, of Breast Cancer Care said: "We are very excited by the launch of letrozole as we know that many women who have had breast cancer worry about its recurrence.

"We speak to many women who are very anxious about coming to the end of their tamoxifen treatment."

Statistics show that one in nine women in the UK will develop breast cancer, with more than 1,000 women dying from it every month.