Faulty gene linked to half of all breast cancers

Scientists have discovered a gene which links half of all breast cancers and when damaged, may be responsible for allowing the disease to develop and grow. The researchers noticed that parts of chromosome 8 were missing from tissue which had been removed from 54 breast cancer patients. When they compared the missing area against the information from the Human Genome Project, they discovered it was the NRG1 gene which had been lost.

'I believe NRG1 could be the most important tumour suppressor gene discovery in the last 20 years as it gives us vital information about a new mechanism that causes breast cancer,' said Dr Paul Edwards from the department of pathology at the University of Cambridge, who discovered the gene with his colleagues.

In 84 per cent of the breast cancer cell lines tested, the NRG1 gene showed only limited activity and in some cases was completely 'switched off'.

'In every case we looked at where a big chunk of chromosome 8 had been lost, at least part of the gene was lost,' said Edwards, who added that when the gene is faulty, healthy tissue loses the ability to protect against cancer cells.

Arlene Wilkie, director of research and policy at Breast Cancer Campaign, which part-funded the study said: 'This research is a major step forward in understanding the genetics of cancer and could open up a host of new strategies to improve diagnosis and treatment.' She added: 'In the UK 12,000 women die from this disease every year, so it is vital we understand how breast cancer develops in order to stop it happening.'

Previous research has shown that the NRG1 gene is implicated in other cancers such as bowel, prostate and bladder cancer. Edwards said that we now have 'got strong evidence that the gene is implicated in breast cancer but we have no reason to think it's not the same for other cancers, including prostate and colon cancer.' The researchers acknowledge that further study is now needed to identify what causes this gene to become damaged or lost and whether the results could be used to develop treatments and new ways of screening people who may be susceptible to developing cancer.