Breast cancer patient Ann Marie Rogers won her legal battle for NHS treatment with the drug Herceptin in the court of appeal yesterday, but primary care trusts will still be free to ration it for other women.

Ms Rogers, 54, hailed the "humanitarian" ruling, which she said had given her back her future and declared: "I feel like I've taken on the world and beaten it, not just for me but for everyone else."

But healthcare lawyers were quick to point out that the ruling does not open the way for every woman who could benefit from Herceptin to demand free treatment.

David Lock, head of the healthcare practice at law firm Mills & Reeve, said: "The decision does not mean that every PCT is obliged to fund every request for Herceptin. The court makes very clear that a primary care trust is entitled to balance its books by rationing Herceptin."

Ms Rogers, a divorced mother of three, went to court to fight a refusal by Swindon Primary Care Trust (PCT) to provide her with Herceptin, a decision she likened to a "death sentence". She is among the one in five breast cancer sufferers with an aggressive form of the disease - HER2 positive - which responds to the drug.

Herceptin has been licensed and approved so far only for late-stage HER2 positive breast cancer, and Ms Rogers' cancer is in the early stage. But after trials indicating that it halves the chances of recurrence in early stage sufferers, such patients have been fighting to be given the drug on the NHS - despite it not being licensed, or approved by the National Institute for Health and Clinical Excellence (Nice).

Some trusts are funding the treatment, which costs £26,000 a course. But many, such as Swindon, have been paying for it only in exceptional cases.

Ms Rogers' battle paid off yesterday when three court of appeal judges overturned an earlier decision by a high court judge in favour of the trust.

In a unanimous judgment the Master of the Rolls, Sir Anthony Clarke, Lord Justice Brooke and Lord Justice Buxton ruled that Swindon's policy of funding only exceptional cases was irrational and therefore unlawful.

Swindon's policy stated that cost was not a consideration, going beyond health secretary Patricia Hewitt's declaration, last October, that trusts should not refuse Herceptin "solely" on grounds of cost.

The judges held that, once the trust said there were no financial constraints, there was no rational basis to provide the treatment to one patient but not another.

But trusts will still be able to choose between patients as long as they make cost a factor in their decision, the judges held.

Peter Edwards, managing partner of the healthcare law firm Capsticks, said the judgment means PCTs "can continue to determine eligibility for Herceptin on the basis of the availability of resources, the clinical needs of the patient, and potentially personal and social circumstances."

Ms Rogers, a former restaurant manager from Haydon Wick, Swindon, will continue to receive Herceptin until her course of treatment finishes in a few months. Speaking outside court, she said: "I did this for all women battling this dreadful disease. I can now look towards the future and have more confidence that I will win this battle against breast cancer."

Jan Stubbings, chief executive of Swindon PCT, which was refused permission to appeal to the House of Lords, although it can apply directly, said the trust would "now revisit our policy taking into consideration the points made by the court."

Gill Morgan, chief executive of the NHS Confederation, said: "Today's ruling will have significant implications for the prescription of all unlicensed drugs - not just Herceptin. The NHS will need to take stock of the broader ramifications."

Nice is expected to decide on whether to approve the drug in July and, if approval is given, every eligible patient will be able to receive the treatment by October.

A Department of Health spokesman said: "We have clarified that PCTs should not rule out treatments on principle but consider individual circumstances when reaching decisions and should not refuse to fund Herceptin solely on the grounds of cost of the drug. This position remains unchanged."

Christine Fogg, joint chief executive of Breast Cancer Care said: "Clinicians should be able to feel confident that they can prescribe the treatment their patients could benefit from, wherever and whenever they need it."

Explainer: Herceptin

Herceptin, the so-called "wonder drug" for which Ann Marie Rogers was battling - can still be refused by primary care trusts after yesterday's judgment if they can argue it is unsuitable and costs too much.

That could all change in July if Nice, the body which regulates a drug's clinical and cost effectiveness, approves its use for HER-2 positive early stage breast cancer. If that happens it will be standard practice to prescribe it. Around 5,000 of the 41,000 women who contract breast cancer each year will be suitable for treatment at an annual cost of around £122m. Its manufacturer Roche applied to extend the drug's use to the early stages of the disease in February.

The drug first has to be licensed by the European Medicines Agency (EMEA). A panel will analyse the data this month. If the EMEA decides that the drug is safe, Nice's appraisal committee will meet on May 25 to discuss the scientific evidence and costs. The agency, which has been criticised for taking too long to make judgments, has already said it will fast-track its decision, and yesterday confirmed this would happen in July.