A cancer charity today cautioned against a new treatment for gut and kidney cancers being seen as a 'wonder drug'.

The drug, Sutent, has been granted a conditional licence by the European Commission (EC) to treat two deadly cancers that affect the kidneys and the gut.

The drug works by starving tumours of the nutrients they need to develop, by stopping the growth of blood vessels.

Sutent's licence covers its use in the advanced stages of a type of kidney cancer, called renal cell carcinoma, and in gastrointestinal stromal tumour - a rare cancer diagnosed in about 900 people a year in the UK.

The drug is used to treat patients when other anti-cancer drugs have failed to improve their condition. The conditional approval means that the drug's manufacturer, Pfizer Ltd, needs to submit more evidence about the medicine to the EC committee that reviews medicines used in rare diseases.

A spokeswoman for Cancer Research UK said it was too soon to say whether the treatment was a wonder drug.

She said: "Sutent has been shown to shrink tumours but it has shown no benefit for patients with renal cancer in terms of lengthening their life. It has been shown to increase the life expectancy of patients with gastro-intestinal cancer, but it's a rare cancer that affects relatively few people.

"It could be an interesting development but we need to know more. It's very early days."

Stuart Danskin, a senior nurse at the charity Cancerbackup, said: "This is an important type of treatment which offers a new approach for cancers that have not responded to initial treatments. We hope to see more trials with this treatment to determine if it could be effective in other cancers."