1.British scientists are preparing to launch trials of a radical new way to fight cancer, which kills tumours by infecting them with viruses like the common cold.

2.If successful, virus therapy could eventually form a third pillar alongside radiotherapy and chemotherapy in the standard arsenal against cancer, while avoiding some of the debilitating side-effects.

3.Leonard Seymour, a professor of gene therapy at Oxford University, who has been working on the virus therapy with colleagues in London and the US, will lead the trials later this year.Cancer Research UK said yesterday that it was excited by the potential of Prof Seymour’s pioneering techniques.

4.One of the country’s leading geneticists, Prof Seymour has been working with viruses that kill cancer cells directly, while avoiding harm to healthy tissue."In principle, you’ve got something which could be many times more effective than regular chemotherapy," he said.

5.Cancer-killing viruses exploit the fact that cancer cells suppress the body’s local immune system."If a cancer doesn’t do that, the immune system wipes it out.If you can get a virus into a tumour, viruses find them a very good place to be because there’s no immune system to stop them replicating.You can regard it as the cancer’s Achilles’ heel."

6.Only a small amount of the virus needs to get to the cancer."They replicate, you get a million copies in each cell and the cell bursts and they infect the tumour cells adjacent and repeat the process," said Prof Seymour.

7.Preliminary research on mice shows that the viruses work well on tumours resistant to standard cancer drugs."It’s an interesting possibility that they may have an advantage in killing drug-resistant tumours, which could be quite different to anything we’ve had before."