Researchers hope they can harness the immune system and use the antibodies that cause allergies to target cancer cells.

Ovarian cancer, which affects 6,000 women in the UK each year, is currently treated using a combination of surgery, chemotherapy and expensive specialist drugs such as Taxol.

But the researchers, at King's College London, found that an antibody called IgE - which is involved in allergic disease - could trigger an immune response against tumour cells.

Immune beacon

In hayfever, IgE attaches itself to pollen and then acting as a beacon to other antibodies - this immune response is what causes the sneezing and itchiness associated with the condition.

The King's researchers said laboratory tests had shown IgE worked in a similar way with ovarian cancer cells, except in this case the antibodies come and destroy cancer cells.

Professor Hannah Gould, who led the research, said: "Antibodies are important as they are proteins that the body develops naturally in the blood to fight infection.

"Early indications show that by harnessing the body's natural defences this antibody has the potential to stimulate the immune system into producing cells that are able to attack this cancer."

Useful condition

She told BBC News Online that any treatment would essentially make people allergic to cancer.

Gordon McVie: "Exciting discovery"

"But they would have a useful allergy," she said. "The allergy would cause the cancer to stop growing - it would inhibit its growth."

Although such treatments would be a long way off, the work at King's had shown that the theory worked and paved the way for clinical trials, she said.

Professor Gordon McVie, director of the Cancer Research Campaign, said it was an exciting piece of work.

"It could not only expand our knowledge if how cancer cells are recognised, but could also pave the way for a new treatment for ovarian cancer," he said.