Breast cancer victims who would currently be refused the 'miracle' drug Herceptin by the NHS have been treated by their private medical insurers instead.

Bupa says that since last year it has provided Herceptin to about 100 women who have been diagnosed in the early stages of the deadly HER-2 positive form of breast cancer, while Standard Life has paid for the drug in 30 early stage cases. Norwich Union has also provided funding for Herceptin in early stage cases since June last year.

Herceptin recently hit the headlines as two women with early stage breast cancer went to the High Court in a bid to get treatment with the drug through their health trusts. A year-long course of Herceptin costs more than £20,000, and some cash-strapped trusts have refused the drug in early stage cases, even though Health Secretary Patricia Hewitt has ordered them to provide it if doctors think it will help.

The drug, which is used after surgery, radiotherapy and chemotherapy to prevent HER-2 positive recurring, has been prescribed by the NHS for women with late-stage cancer since September 2002. But its manufacturer, Roche, has only recently applied to the licensing body, the National Institute for Health and Clinical Excellence, for approval for it to be used in early stage cases.

Shelley Jackson first spotted she had a lump in her breast when she was seven months' pregnant: 'My GP initially thought it was a blocked milk duct. But it didn't go away, so after I had Ella [her baby] I mentioned it during a check-up, and was referred to a consultant.'

Shelley, 39, was diagnosed with HER-2 positive breast cancer, but lives in Windsor, where Herceptin was withheld by the local health trust. Luckily, she had private medical insurance with Bupa, which was willing to pay for the drug on the recommendation of her doctor.

'If someone had said I couldn't have it, I would have been devastated,' she says. 'You are fighting to get better anyway, so you don't need an extra fight for the drug that will help you get there.'

Herceptin can cause heart failure, so Bupa will only fund the drug when it has been decided jointly by the patient and her oncologist that this is the right action. Dr Paula Franklin, Bupa's deputy medical director, says: 'Many drugs have potential side effects. We haven't made this decision in the absence of evidence. We feel we have made an appropriate review. And we are not alone - parts of the NHS have funded Herceptin in early stage cases.'

But not all private medical insurers will cover the cost of Herceptin. Axa PPP says: 'Our policies provide for the treatment of conditions that respond quickly, which we define as acute. For cancer, this can include surgery, radiotherapy and chemotherapy. We do not pay for treatment that is not established as being effective, that is preventive or long term. So we do not pay for Herceptin treatment of breast cancer that has not spread [that is, primary disease]. We are aware of recent trials with Herceptin for treating breast cancer that has not spread, but this evidence has yet to be appraised by the licensing authorities so has not been subject to the proper scrutiny.'

Bupa says women who want to ensure they are fully covered should ask their PMI insurer the following questions:

· Will I be covered for secondary cancer (ie, if I get breast cancer and then it spreads to my lungs)?

· Will my private insurer cover me for every stage from diagnosis to treatment?

· Will it cover for Herceptin for both early and late stages of cancer, and if so, for how long?

· What quality accreditation does it have in place to ensure that I am diagnosed and treated only by experts?

· At what point will it stop paying for my cancer care?

What is herceptin?

Women who have lots of HER-2 receptors on their cancer cells are known has HER-2 positive. About 25 women a day are diagnosed with it. Herceptin is only effective for this particularly fast-growing cancer. It works by preventing growth factor produced naturally in the body from attaching to the HER-2 receptors on the surface of cancer cells, and stimulating those cells to grow and divide. A large-scale global trial involving 5,000 breast cancer patients showed treatment with Herceptin after chemotherapy could reduce the chances of cancer recurring in about 50 per cent more women, compared to those treated only with chemotherapy.