Scientists discover high risk gene for ovarian cancer

8^th August 2011 - Scientists funded by Cancer Research UK have discovered that women who carry a faulty copy of a gene called RAD51D have almost a one in 11 chance of developing ovarian cancer. In their study, published in Nature Genetics, they describe this as the most significant ovarian cancer gene discovery for more than a decade.

The team at The Institute of Cancer Research (ICR) examined DNA from women from 911 families with ovarian and breast cancer and compared differences in DNA with a control group of 1,060 people from the general population.  

The team discovered eight gene faults in the RAD51D gene in women with cancer, compared with one in the control group.

One in 11 chance of ovarian cancer

Ovarian cancer is the fifth most common cancer in women - around 6,500 cases are diagnosed annually in the UK. The researchers estimate that RAD51D gene faults are present in almost one per cent of women with ovarian cancer - around 50 UK women each year.  Around one woman in 70 in the general population is at risk of developing ovarian cancer, but for those with a RAD51D gene fault this risk is increased to one in 11, making these women six times more likely to develop the disease.

Key repair pathway fails

The RAD51D gene is important for repairing damaged DNA. When the RAD51D gene is faulty, a key repair pathway fails. This means DNA damage is not fixed and DNA faults build up in cells, making them more likely to turn into cancer.

Cancer Research UK-funded scientist and study author Professor Nazneen Rahman, head of the Division of Genetics and Epidemiology at The Institute of Cancer Research and The Royal Marsden, said: "Women with a fault in RAD51D gene have a one in 11 chance of developing ovarian cancer. At this level of risk, women may wish to consider having their ovaries removed after having children, to prevent ovarian cancer occurring."

 According to Professor Rahman: "There is also real hope on the horizon that drugs specifically targeted to the gene will be available."

Professor Nic Jones, Cancer Research UK’s chief scientist, said: "It’s incredibly exciting to discover this high risk gene for ovarian cancer. It’s further evidence that a range of different high risk genes are causing the development of breast and ovarian cancer and we hope there are more waiting to be discovered in different cancers." 

"We believe the results of this research will help inform personalised treatment approaches and give doctors better information about risks of cancer to tell patients."

Another piece of the jigsaw

Harpal Kumar, Cancer Research UK’s chief executive, said: “Survival from ovarian cancer has almost doubled in the last 30 years. This landmark discovery is another piece of the jigsaw deepening our understanding of the disease. We hope this will have a significant impact in providing more personalised treatments for patients.

Ovarian cancer often develops without any clear symptoms and many women only discover they have it once it has spread. Survival for ovarian cancer has improved over the last 35 years, but long-term rates are still low. For women diagnosed in England during 2003-07, the one- and five-year age-standardised relative survival rates are 70% and 41% respectively, compared with 42% and 21% respectively, for women diagnosed in England and Wales during 1971-75. Early diagnosis is an important factor in determining ovarian cancer survival.

 It may be possible eventually to offer families with ovarian cancer a genetic test to see if they carry the faulty RAD51D gene.

Cancer Research UK is the largest single funder of ovarian cancer research in the UK - last year it spent more than £12 million of public donations on tackling the disease.