Researchers have just discovered that women with a certain variant of the RAD51D gene may have a significantly higher risk of developing ovarian cancer. Knowing who’s at risk can help women and their doctors make better decisions about how to tackle the disease.

Some ovarian cancers have been linked to certain genes (like the BRCA genes) in the past, and women with a family history of ovarian or breast cancers are at higher risk. Ovarian cancer is the fifth most common cancer in women, and takes the lives of more women than any other cancer of the reproductive system.

The authors also suggest that women with the faulty gene may also want to consider having their ovaries removed after they have finished bearing children, as some women with the BRCA genes opt to do.

In the current study, the researchers looked at the DNA of 911 women with family histories of breast and ovarian cancer and compared it to the DNA of women with no family history. They found that women with a particular fault in the RAD51D gene had a one in 11 chance of developing ovarian cancer, compared to women with normal copies of the gene. The authors conclude that RAD51D is an "ovarian cancer predisposition gene."

Luckily, drugs known as PARP inhibitors, which are effective against cancers caused by the BRCA 1 and BRCA 2 genes, were also shown to be effective against RAD51D-related ovarian cancers. Major drug companies are working to develop the PARP inhibitors, which cause cancer cells to die by blocking their DNA repair systems.

The authors also suggest that women with the faulty gene may also want to consider having their ovaries removed after they have finished bearing children, as some women with the BRCA genes opt to do.

The more researchers understand how and why certain cancers develop, the more tools they can develop to help fight against them. This research adds one more piece of the puzzle to understanding why ovarian cancer develops in some women but not others.

The study was carried out by a team at The Institute of Cancer Research, in Sutton, UK, and published in the August 7, 2011 online issue of Nature Genetics.