A new breast cancer drug that can extend the lives of sufferers cannot be provided on the NHS, the drugs rationing body has announced.

The drug, Faslodex, may help women with breast cancer to live for a further three years but will not be provided on the NHS, the National Institute of Health and Clinical Excellence has ruled.

The drug costs £500 a month, up to 84 times more than alternatives already available, and the evidence it works any better is 'uncertain', a spokesman for Nice said.

Faslodex, also known as fulvestrant, is made by AstraZeneca, and is licensed to treat certain forms of breast cancer in older women who have already received some treatments.

 It was to be used as an alternative to anastrozole and letrozole which are already in use in the NHS and are cheaper.

Data shows women on Faslodex live for an average of 36 months, compared to 32 months for those on anastrozole and 31 months for those on letrozole.

Sir Andrew Dillon, Chief Executive of Nice, said: "While there is evidence that fulvestrant can delay the growth of breast cancer, our independent committee found that when used according to its marketing authorisation, its effectiveness is uncertain compared to aromatise inhibitors, which are currently the preferred treatment options on the NHS.

"NICE has to ensure that the NHS provides treatments that bring benefits which are value for money. As fulvestrant has not been proven to be cost-effective, we cannot justify diverting NHS funds from other areas of healthcare in order to fund its use."

If no appeals are received by Thursday 24 November, Nice hopes to publish final guidance for the NHS in January.

Maria Leadbeater, Clinical Nurse Specialist at Breast Cancer Care said the decision was 'disappointing'.

She added: "While we recognise that drug decisions must be based, to some degree, on cost effectiveness, this approach can fail to take into account what is important for the patient.

Treatment options for people living with secondary breast cancer are limited, so any drugs which delay time to progression are especially valuable.

"We do, however, welcome the acknowledgement of the importance of additional treatment options for this patient group. At Breast Cancer Care we support many people living with secondary breast cancer, some of whom are being treated with Fulvestrant, so we are also reassured to hear that these women will be able to remain on the drug until they or their consultant considers it appropriate to stop."