CANCER GENE RISK FOR 1 IN 5 WOMEN

REVEALED: Study finds 179 DNA faults that significantly raise dangers YOUR BRILLIANT GOOD HEALTH PULLOUT IS FREE INSIDE

SCIENTISTS say one in five women are in greater danger of getting breast cancer because of faults in their genes. Most women already know that if their mother, daughter or sister has the cancer, they themselves are at higher risk of getting the disease.

But the largest genetic study ever carried out on this type of cancer has managed to pinpoint the 179 separate mutations passed on through families.

For one in five women, the errors written into their genes mean they have almost a third higher chance of getting breast cancer. An unlucky 1% have three times the risk.

This remarkable research could now be used to save lives, as a simple blood test could identify these women.

One in nine Irish women will develop

breast cancer in their lifetime, with 2,500 new cases diagnosed every year. Annually, the disease kills some 680 people here.

An international team of hundreds of scientists, led by Cambridge University, in England, analysed DNA from 275,000 women. Their results almost double the number of genetic variants now known by scientists to cause breast cancer.

The study looked at 11.8million single-letter ‘spelling mistakes’ in women’s DNA which increase their risk of breast cancer. It discovered nine more variations affecting the gene BRCA1, which caused actress Angelina Jolie to have a double mastectomy after discovering she carried the gene which led to her mother’s death.

They have confirmed 107 genetic variants and discovered 72 new ones. The discovery allowed the team to calculate that one in ten women have a 70% higher risk of getting breast cancer.

Dr Robert O’Connor, head of research with the Irish Cancer Society, welcomed the findings, saying: ‘It gives better definitions and explanation as to some of the origins of breast cancer.’

He added: ‘It does present a number of challenges and problems as well, because there are difficulties in actioning some of the information, so what this is showing is that often there are multiple mutations that can give rise to breast cancer. It’s not necessarily a specific one.’

He said there are challenges in helping people to understand the risk and how they can mitigate it. ‘Just because you’re at increased risk of breast cancer, doesn’t mean you’re going to get it.’

He added: ‘We know there are a number of lifestyle factors that can increase the risk of cancer. For post-menopausal breast cancer, for example, being overweight is an increased risk factor and alcohol consumption is a pretty big risk factor that, again, people can have control over.’

Professor John Crown, an oncologist in St Vincent’s Hospital, Dublin, said the research is likely to have an important impact in terms of cancer prevention and early diagnosis. He said: ‘Most patients with breast cancer have no clear family basis, a very important minority do. In recent years it has been possible to test patients to see if they had susceptibility genes. If they have them, such patients require additional screening, additional testing and sometimes preventative surgery.

‘We were always of the opinion that there were other patients whose family histories were very suspicious but who tested negative on the classic gene testing. And so this new research is important as it appears to be identifying additional genes which can be tested which will enable us to extend the benefits of genetic screening further.’

Prof. Crown said the research highlights the need for investment in genetic testing services here.

Last year the UK’s chief medical officer, Sally Davies, used her annual report to talk about ‘riskbased’ screening for the cancer instead of all women being screened from the age of 50.

The new study, which used microchips costing less than £50 (€56) to test women’s breast cancer risk from their blood, could bring this closer to reality.

Professor Doug Easton, one of the lead investigators for the study from Cambridge University, said: ‘We have known for a long time that breast cancer runs in families and has a substantial genetic component.

‘But judging someone’s risk based on their family is a blunt tool. This provides the exact genes which are important.

‘It means some women could be offered more precise screening, using an MRI machine, if their genetic risk is higher.’

The research also offers hope for women like Angelina Jolie, who had thought their chances of breast cancer jump by 70% if they carry the gene. In fact it is only 35%, the new study shows.

‘Some could get precise screening’