A NEW approach to treating cancer, which involves starving tumours of their blood supply, has been proved to work in humans, scientists said yesterday. Seventeen patients, with a range of cancers - including breast, bowel and lung - received the treatment at Mount Vernon and Hammersmith hospitals, in London. The early results show that the drug used, Combretastatin, derived from the African bush willow, acts in a different way from conventional chemotherapy, opening up a new front against the disease.

A NEW approach to treating cancer, which involves starving tumours of their blood supply, has been proved to work in humans, scientists said yesterday. Seventeen patients, with a range of cancers - including breast, bowel and lung - received the treatment at Mount Vernon and Hammersmith hospitals, in London. The early results show that the drug used, Combretastatin, derived from the African bush willow, acts in a different way from conventional chemotherapy, opening up a new front against the disease.

Some patients who were given the drug experienced pain at the site of the tumour, indicating that the drug was working and cutting off the tumour's blood supply.

Dr Gordon Rustin, director of medical oncology at Mount Vernon, who presented the findings at a conference in London yesterday, said: "This study is very exciting because it is the first time in cancer research that a drug has been shown to reduce blood flow to patients' tumours. This proves that the theory of starving someone's tumour of oxygen can work in practice, and it has opened the door for new cancer treatments in the future."

Combretastatin is one of a new family of drugs being developed by the Cancer Research Campaign and the biotechnology company Oxigene. The drugs appear to be effective against all solid tumours, but a tumour must be at least one millimetre in diameter, about the size of a grain of rice, to have its own blood supply. The drugs work differently from chemotherapy, which directly attacks cancer cells.

Two similar phase-one trials to test the safety of the procedure are underway in the United States. In all three trials, patients receive weekly infusions of the drug and are monitored by magnetic resonance imaging (MRI) scans, which show the effect on the flow of blood to the tumours. A larger trial could start in the United Kingdom next year, and if that were successful the drug could be made widely available in four or five years, the Cancer Research Campaign said. Professor Gordon McVie, director-general of the campaign, called the approach "revolutionary".

"It can be likened to cutting off the supply route to an invading army and provoking starvation. The principle has been proved in this preliminary trial. Further tests will be necessary to evaluate the benefits to patients," he said. But Dr Rustin warned that the treatment was unlikely to cure the cancers at which it was aimed, because restriction of the blood supply would still leave an outer rim of tumour cells that could obtain nourishment from the normal tissue surrounding them. However, in combination with other drugs, it might improve the effectiveness of existing treatments.

More than a year ago, tests on mice showed that Combretastatin selectively attacked blood vessels supplying tumours. Why it spared other blood vessels is not understood.

Research on the family of drugs was led by Dr Judah Folkman, of the children's hospital at Harvard Medical School, in Boston. Dr Folkman has worked for 30 years on angiogenesis - the growth of blood vessels. But the new drugs work by attacking existing blood vessels, rather than preventing their growth.

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