Researchers at Sutton’s Royal Marsden Hospital in Sutton say they have made the biggest breakthrough in prostate cancer in 60 years.

The hospital’s experts say trials of a new drug, abiraterone, has shown a high success rate in treating men with an aggressive, drug-resistant and often fatal form of prostate cancer.

The phase one clinical trial, which involved 21 men was undertaken by the Institute of Cancer Research and the Royal Marsden Hospital.

Between 70 and 80 per cent of the men on the trial experienced dramatic reductions in PSA - a protein marker for prostate cancer - and tumour shrinkage, even in tumours that had spread to bone and other tissue.

Scientists said the drug could potentially treat up to 80 per cent of patients with a deadly form of prostate cancer currently resistant to chemotherapy - potentially prolonging the lives of up to 10,000 British men every year as well as giving them relief for back pain.

Lead researcher Dr Johann de Bono said the drug abiraterone worked to block the generation of key hormones that drive the growth of prostate cancers.

“Clinical benefits included evidence of PSA falls and tumour shrinkage which was observed in 70-80 per cent of patients,” he said.

“Abiraterone works not only in blocking the generation of these hormones in the testes, but also elsewhere in the body, including generation of hormones in the cancer itself.

“Tumour shrinkage was determined by a reduction in the blood level of prostate specific antigen (PSA) – a protein associated with prostate cancer activity, and also with analyses of CAT scans, MRI scans and bone scans.

“The Royal Marsden patients in this study have been monitored for up to two-and-a-half years and with continued use of abiraterone they were able to control their disease with few side effects. A number of patients were able to stop taking morphine for the relief of bone pain.

“These men have very aggressive prostate cancer which is exceptionally difficult to treat and almost always proves to be fatal.

“We hope that abiraterone will eventually offer them real hope of an effective way of managing their condition and prolonging their lives.

“It is envisioned that this drug will be available for general use from 2011 and we hope it can become widely available. In the interim, it is available through clinical trials only.”