Ovarian cancer gene discovered

By Dr. Ananya Mandal, MDAug 8 2011

A new study finds that around one woman in 70 is at risk of developing ovarian cancer, which claims more than 4,200 lives a year and this could be attributed to a faulty RAD15D gene. The gene raised the risk to one in 11.

This finding came from the scientists at the Institute of Cancer Research which is connected to The Royal Marsden hospital in London. Professor Nazneen Rahman, head of genetics and epidemiology, said, “At this level of risk, women may wish to consider having their ovaries removed after having children, to prevent ovarian cancer occurring.” The study published in the journal Nature Genetics, is limited to the knowledge that faulty copies of this gene raise ovarian cancer risk. But Prof Rahman said, “There is also real hope on the horizon that drugs specifically targeted to the gene will be available.” The team compared DNA of women from 911 families with ovarian and breast cancer, to that from 1,060 people in the general population.

Cancer Research UK, which helped fund the study, described it as “the most significant ovarian cancer gene discovery for more than a decade”. Prof Nic Jones, the charity'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 personalized treatment approaches and give doctors better information about risks of cancer to tell patients.”

According to Annwen Jones, chief executive of the charity Target Ovarian Cancer around 10 per cent of the 6,500 new cases of ovarian cancer every year are estimated to be in those with “a strong family history” of the disease. She said, “This new information, in the future, could help more women with a family history understand their personal risk of developing this disease.” Survival rates for ovarian cancer remain poor compared to other types. While 92 per cent of breast cancer patients now survive for at least five year from diagnosis, for ovarian cancer only about four in 10 do.

Tests to identify those at highest risk are expected to be available within a few years, according to Cancer Research UK.

The finding should also speed the search for new drugs. Laboratory experiments already suggest that cells with faulty RAD51D are sensitive to PARP inhibitors - a new class of drugs designed to target cancers caused by faults in two known breast and ovarian cancer genes, BRCA1 and BRCA2. Several large drug makers, including Abbott, Merck, Pfizer, Sanofi-Aventis and AstraZeneca are developing PARP inhibitors, which work by blocking DNA repair mechanisms in cancer cells, stalling the cell cycle and leading to cell death.

Rahman said the identification of RAD51D pointed to PARP inhibitors as a new class of drugs that might offer fresh hope. Initial tests in the laboratory found that cells with faulty RAD51D were highly sensitive to this class of drugs. “PARP inhibitors work because they were designed to target DNA repair pathways…They haven't been used in patients in that context yet but we would predict they would behave in the same way,” she said.