Leading article: The NHS should explain

Many breast cancer patients are delighted by the approval of Herceptin for NHS use. But the joy of this newspaper, which campaigned on their behalf, is bounded. In a minority of cases of early breast cancer, Herceptin is an effective treatment. The difficulties arise because it is only the most famous of a new family of drugs already proven effective against different forms of cancer.

Herceptin was given fast-track approval by Nice, the National Institute for Clinical Excellence. It is hard to avoid the suspicion that the procedure was accelerated partly by lobbying by popular cancer charities and by a media campaign for a fashionable cause. The Independent on Sunday played a leading role in that campaign, of which we are proud, but the Herceptin decision is very much the beginning of a victory rather than an occasion for lasting self-congratulation.

Today, we return to the question of the 20 other cancer drugs that are still waiting for Nice approval. In none of these cases does there appear to be doubt about the effectiveness or the safety of the treatment. On page 13, we report the case of Tamar Bailey, who died last week, and whose 26-year life could have been prolonged by early treatment with Avastin, a drug that shrinks tumours. But Avastin is still waiting for Nice approval, and so Tamar's primary care trust refused to pay for it.

Of course, Avastin is expensive. It costs £20,000 a year per patient. We do not argue that all treatments that could extend lives - or even all treatments that could extend the lives of young people - should be funded. If Nice decides that public money could secure better quality of lives elsewhere, that would be a decision that could be debated and challenged. What is not acceptable, though, is to use bureaucratic delay as a way of rationing by stealth.

As we have argued before, openness is the key. Everyone accepts that limited NHS resources have to be prioritised; what matters is that the process by which such priorities are set commands respect. The delay in approving the new generation of cancer drugs - which are almost certain to be approved - undermines that respect. So, too, for example, does Nice's refusal to publish the computer model used to assess the cost-effectiveness of drugs to treat Alzheimer's disease.

It may be objected that we are arguing for clinical priorities to be set by public sentimentality and media sensation. And it is certainly the case that breast cancer - and Herceptin - attracts more attention than the bowel cancer that killed Tamar or the Avastin that could have helped her. Yet the answer to that is more information and more openness, not less. The development of a new generation of expensive anti-cancer drugs requires the NHS to make some difficult trade-offs. But the public support needed to make those trade-offs can only be obtained by facing them explicitly and openly.