Australian researchers have uncovered six new gene variations that increase a woman's risk of ovarian cancer and the finding will help doctors better diagnose its cause.

The QIMR Berghofer Medical Research Institute, together with the University of Cambridge, studied more than 70,000 women from 30 countries and regions, and found 18 known ovarian cancer gene regions, up from 12.

QIMR Berghofer cancer program head Professor Georgia Chenevix- Trench told the Australian Broadcasting Corportation (ABC) on Wednesday that the discovery would help the better diagnosis and prevention of ovarian cancer and would reveal causes of other cancers.

"The more we find these kinds of regions in different cancers and different conditions, the more we realise that there are quite a lot of similarities," Chenevix-Trench said.

"So for example, one of the regions we found is also involved in the risk of pancreatic cancer, another region that's also involved in the risk of breast cancer, and another of the regions we found is involved in the risk of endometriosis, which is the inflammatory condition that can predispose to ovarian cancer.

"So understanding the genetics can also really help us get a handle and an understanding of the biology behind these diseases.

"If you've already got a very strong risk of ovarian cancer because of a mutation, the subtle differences that these other genetic regions can impose on top of that can make quite a big difference as to whether you are likely to get ovarian cancer at 30 or at 50."

Chenevix-Trench said by understanding more about who is at highest risk, researchers should be able to modify clinical treatment accordingly and that should reduce the risk of ovarian cancer.

She said ovarian cancer was difficult to diagnose, and the discovery of these gene variants should make it easier to prevent.