Brain tumour breakthrough

Scientists believe they have identified a gene that triggers brain tumours, in what has been described as a potentially "major discovery". The defective gene was found in about a third of tumour samples of the most lethal form of brain cancer, glioblastoma multiforme. Similar gene mutations were seen in some prostate and breast cancer cells.

The gene, known as PTEN, is believed to be involved in controlling cell growth, preventing the kind of rampant cell division that leads to cancer. It is thought mutations in the cancerous gene may deactivate it, allowing tumours to develop.

The findings, from a team of researchers led by Jing Li, of Columbia University College of Physicians and Surgeons in New York, were published yesterday in the American journal Science.

Glioblastoma multiforme kills between 5,000 and 6,000 people a year in the US. There are no similar figures available in the UK, but all types of brain and central nervous system tumours together account for about 2 per cent of deaths in western countries. Their overall incidence is between one and 15 deaths per 100,000 of population.