Cancer sufferers are given hope of painless treatment

Researchers have found a way of making tumour cells far more sensitive to lower doses of anti-cancer drugs. This could mean patients no longer have to deal with the side effects of chemotherapy.

The treatment attacks healthy cells as well as cancer cells, and can cause nausea, vomiting and hair loss.

Other side effects include liver and kidney problems and permanent damage to fastgrowing cells, such as those in the reproductive system.

The U.S. research focused on 'silencing' or 'switching off' genes that appear to be turned on as part of the cancerous process.

In an experiment on lung cancer, they found a set of genes that, when used with chemotherapy, made tumours much more vulnerable to the treatment. More than 20,000 genes in lung cells were screened. They were then examined to see their susceptibility to the chemotherapy drug Taxol.

The scientists, led by Michael White of the University of Texas Southwestern Medical Centre, in Dallas, identified 87 genes that made tumours more susceptible to the cancer drug - even when the dosage was 1,000 less than normal.

Taxol, also known as paclitaxel, is also used to treat ovarian cancer and advanced breast cancer. Its side effects treatment include fatigue, nausea, numbness and bone-marrow depletion - leading to lowered immunity from infections.

The findings, published in the journal Nature, suggest it should be possible to treat patients with lower doses of chemotherapy - which will help keep healthy cells free from harm.

'More potent at lower doses'

Dr White said: 'Chemotherapy is a very blunt instrument. It makes people sick and its effects are very inconsistent.

'Identifying genes that make chemotherapy drugs more potent at lower doses is a first step towards alleviating these effects in patients.'

It is thought that the findings will lead to further research into how they can be used most effectively.

One option is to screen a patient's cancer for specific genes which make it more vulnerable to drugs. These could then be administered in low doses. The information could be used to create drugs which won't run treatment specifically target the critical genes, making the cancer cells more sensitive to treatment.

The study focused on why some cancer patients fail to respond to chemotherapy and why some develop severe sideeffects from the treatment.

It used a revolutionary technique called RNA-interference which allows scientists accurately to target a gene and turn down its activity.

But researchers have emphasised that more research on animals and in the laboratory is needed before clinical trials can go ahead.

It is thought that it could take up to five years before clinical trials can get under way - and up to ten years before new drugs can be developed on the back of the findings.

Dr White added: 'We're still at the beginning but this sort of approach is very fast and very effective.' Recent research has also provide an insight into how breast cancer can be more effectively treated.

A team of scientists in New York and Barcelona have discovered a 'gang of four' genes which are responsible for the spread of the cancer.