Cancer Research UK-funded scientists 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, the most significant ovarian cancer gene discovery for more than a decade, reveals a study in Nature Genetics1 today (Sunday).
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 1060 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.
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.
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 which make them more likely to turn into cancer.
The team also showed that cells with faulty RAD51D can be selectively destroyed by a relatively new class of cancer drugs called PARP inhibitors. These drugs are showing great promise in clinical trials for the treatment of breast and ovarian cancers with faults in the BRCA1 and BRCA2 genes, which are also important for repairing damaged DNA.