Avastin, a cancer drug which offers a new way to combat colon cancer, has won US approval and boosted the hopes of other sufferers. Nigel Hawkes, Health Editor, left, reports.

What is this drug? What will it do?

It is the first drug to be licensed in a new class of cancer drugs that aim to starve tumours by cutting off their blood supply - the so-called "anti-angiogenesis" drugs.

They have attracted a lot of attention and some controversy after Dr Judah Folkman of Harvard claimed in 1998 to have cured mice of cancer using such a drug. Human trials have not lived up to this initial promise. But Avastin has shown some results in prolonging the life of patients with advanced colon cancer.

Will it be useful for all cancer patients?

Drugs of this sort are appropriate only for solid tumours that need a blood supply. But that covers most of them, excluding leukaemia and myeloma. Avastin is in trials for kidney and lung cancer, and some 30 other experimental drugs of the same type are being developed by several drug giants. including Novaris, Bayer and Pfizer.

Will it be available here on NHS?

It has no European licence yet, and costs are expected to be £2,500 a month, which is likely to raise serious difficulties for funding in the NHS. If it were a cure, of course, such a cost might easily be justified - but for prolonging life for a few months the cost-benefit figures may not stack up.

How big a problem is colon cancer?

Colon cancer is the third most common cancer with nearly a million cases worldwide every year, and 33,000 a year in the UK. If caught early the outlook is good.

Are scientists winning the war against cancer tumours?

Progress in cancer research is slow, but steady. Real breakthroughs are rare, though Novartis' Glivec, for chronic myeloid leukaemia and a rare stomach tumour, is an exception - it seems to provide a cure. There have also been encouraging signs in two recent trials that vaccines may have a role to play in combating cancer. But basically improvements are made up of many small steps, of which Avastin may be one.

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