British gene team are on the brink of cancer breakthrough

It shuts down the rogue genes that cause cancer and is due to be tested on humans for the first time in the next few months.

If successful, the drug will be used to stop the disease spreading to other parts of the body, at the same time improving quality of life and life expectancy.

The technique, known as RNA interference therapy, is still in its early stages of development but one day it could be extended to treat other conditions ranging from asthma to Aids.

The drug works by preventing genes from making disease-causing proteins. Similar in structure to DNA, it should halt the disease in its tracks.

A London-based company, SR Pharma, was awarded a patent for a drug which specifically targets the genes involved in pancreatic cancer - one of the most deadly varieties of all.

Animal tests have shown the treatment both stops the tumour from growing and prevents it from spreading elsewhere in the body.

The first human trials are due to start in the next few months and it could be on the market within three years.

SR chairman Iain Ross said: "We are not attacking the tumour itself but attacking the spread. It is not a cure but it will prolong life and improve quality."

Pancreatic cancer accounts for three per cent of all cancers. It is most common in people in middle and old age.

About two thirds of cases are diagnosed in both men and women aged over 70 years. Often the cancer has a poor prognosis as it doesn't show symptoms until the disease is relatively advanced.

Using the same therapy to target other disease-causing genes could one day lead to new treatments for a host of other cancers and illnesses. "If it is proven to work in humans, interfering RNA will dramatically increase the possibility of producing drugs a lot more quickly," said Mr Ross.

Present naturally in the body, interfering RNA is thought to defend against invading viruses.

However, its importance remained unclear until nine years ago when U.S. scientists showed it had the ability to shut down specific genes.

The discovery of the effects of interfering RNA has proved so important that in October last year the U.S. researchers, Dr Andrew Fire and Dr Craig Mello, were awarded the Nobel Prize for Medicine.

Pharmaceutical and biotechnology companies around the world are now trying to produce drugs which harness the phenomenon.

At the forefront of the research, SR Pharma is the closest to testing a cancer treatment on humans.

Experts say the technique has potential - as long as researchers can administer the drug in a way that ensures it is not broken down by the body before it takes effect.

Hazel Nunn, of Cancer Research UK, said: "From laboratory studies it seems that RNA interference techniques could, in principle, hold the potential to treat a range of diseases.

"But we need to see significant advances in methods of delivering RNA into human cells before this technology could be used to treat diseases like pancreatic cancer."