Two women have become the first in Britain to be given Herceptin, a radical drug for breast cancer - but they have had to pay for it themselves after tracking it down on the internet.

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Louise Thomas and Helen Mabbott both have advanced cancer, and believe that the drug represents their last hope, even though it is not yet licensed for use in the UK.

But despite trials which show it improves survival rates for the disease in certain patients, and lessens the horrific side-effects associated with chemotherapy, it may never be available on the NHS, as it is too expensive.

The treatment costs £20,000 a year per patient, and could cost the government £10m a year.

Internet search

Ms Mabbott, 47 , found out about the drug on the Internet, and family and friends are paying for it with a fundraising campaign.

Helen Mabott found details of Herceptin on the internet

She told the BBC: "With the Herceptin I don't get any bouts of sickness, I don't feel quite as tired, I don't feel as depressed.

"Before I had the Herceptin I thought I had no chance - now I feel a lot more positive."

A study of Herceptin, presented in September at the European Congress of Clinical Oncology, has shown its success in treating cancer which has spread beyond the breast.

Professor Anthony Howell, at the Christie Hospital in Manchester, is overseeing the treatment of the two women.

He said: "It does increase the length of life of patients with cancer, and it's up to the government to take a value judgement on how much that is worth."

The addition of the drug to standard chemotherapy improved survival time by a quarter - on average adding an extra five months.

Professor Howell: 'It will prolong life'

In addition, women taking the drug reported a far better quality of life, with fewer disease symptoms such as pain and shortness of breath.

Herceptin works by targeting a gene, HER2, which is over-produced in many women with advanced breast cancer.

There is too much of the gene in approximately 25 to 30% of breast cancer patients, and these are often those with the most aggressive cancers.

Addition of the drug to other chemotherapy treatments both slowed the overall disease progression and produced tumour shrinkage in more than twice as many patients.

Prohibitive cost

The potential demand for the drug in the UK could be huge, but its cost could be prohibitive.

Stephen Thornton, the chief executive of the NHS Confederation, which represents health service managers, said: "Unfortunately the health service has to take tough decisions about the treatments it can afford.

"If somebody has treatment with a drug of this sort that is money that isn't available to treat somebody else."

The drug is likely to be a candidate for referral to the National Institute for Clinical Excellence, which is already examining the case for funding Taxol, a drug for ovarian and breast cancers which also costs thousands per patient per year.