New hope over prostate cancer

A mutant strain of the common cold virus is being tested as a treatment for prostate cancer, which kills 8,600 men a year in Britain.

American researchers believe they may have found a strain that targets and destroys the tumour, the second biggest cancer killer after lung cancer. A single injection directly into prostate cancers in mice shrank the tumours rapidly, without side-effects. Results reported in the US journal Cancer Research show that after six weeks the tumours were on average reduced to 16 per cent of their previous size. Human trials are due to start soon, according to New Scientist magazine.

Dr Lesley Walker, head of science information at the Cancer Research Campaign, said today: "It sounds very exciting. We would be enormously interested to see if these results can be reproduced in patients. If they were, it would be quite remarkable."

The mutant strain of the virus was created by researchers at the Johns Hopkins Oncology Center in Baltimore, Maryland, and a Californian biotech company, Calydon. Although it can penetrate any cell, it becomes active only in those producing prostate specific antigen (PSA) - a protein involved in the production of semen and found almost exclusively in the prostate. The researchers hope the virus will not only destroy the cancer in the gland but, if injected into the bloodstream, will hunt down cancerous cells spreading through the body.

Dr Walker said a new, effective and safe treatment for prostate cancer was urgently needed. With surgery and radiotherapy, the risk of incontinence or impotence was high, while hormone drug treatments had unpleasant side- effects.