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Global Study Finds 12 New Genetic Wirings Behind Ovarian Cancer

Almost 1,600 Australian women will receive a new diagnosis in 2017.

30/03/2017 11:09 AM AEDT | Updated 31/03/2017 7:25 PM AEDT
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New genetic markers equal more powerful predictions.

A team of international researchers has identified 12 new genetic variants that increase a woman's risk of developing ovarian cancer.

With almost 1,600 Australian women estimated to be newly diagnosed in 2017, the findings offer critical clues about the "wiring" of various complex ovarian cancer types and which women are most (and least) at risk.

Despite the fact that each of these variants has a very subtle risk, we can start to use these new genetic markers to make more powerful predictions.

"We are realising more and more that ovarian cancer is not a single disease. Whilst the one commonality is that it starts in the ovary or in the fallopian tube, each type of cancer is associated with different genetic variants," Professor Georgia Chenevix-Trench from Australia's QIMR Berghofer Medical Research Institute told The Huffington Post Australia.

"This is a huge experiment that has been documented all over the world. The results feed on work that we've been doing for ten years, but they're bigger and better."

The study, published in Nature Genetics, saw 418 researchers trawl through the DNA of almost 100,000 people, including patients with the most common types of ovarian cancer.

Researchers came together from the Ovarian Cancer Association Consortium and the Consortium of Investigators of Modifiers of BRCA1/2, led by Chenevix-Trench, to better understand inherited genetic risk.

"What we commonly know is that women who have inherited faults (or mutations) of the BRCA1 and BRCA2 gene have an increased risk of ovarian cancer -- but it is far from 100 percent because there are all of these other genetic variants," Chenevix-Trench said.

"We've discovered in the last few years that the genetic variants in those families, who already have a strong mutation of BRCA 1/2, tend to be the same as the genetic variants that affect risk in the general population."

Prior to the study, researchers knew of 18 common genetic variants, each of which has "a very subtle increased risk". Now, they have identified 12 more.

What does all of this mean?

According to Chevenix-Trench, the findings offer direction to not only identify women at risk but also to tailor risk prevention.

"This gives us more genetic variants that we now need to understand at a biological level," Chevenix-Trench said.

"Despite the fact that each of these variants has a very subtle risk, we can start to use these new genetic markers to make more powerful predictions. The next stage will be developing better models, so that instead of women receiving information on an average risk, they will receive information on their individual risk."

If you have a 70 percent chance of having ovarian cancer, you are very likely to consider having your ovaries removed, whereas if you have a low chance, you may choose not to go ahead.

While the study has advanced knowledge of the genetic drivers, work remains in combining this with other risk factors, including environmental factors.

And women who already carry a mutation of the BRCA1 and BRCA2 gene will remain a priority.

"This is where there is real urgency. If you have a 70 percent chance of having ovarian cancer, you are very likely to consider having your ovaries removed, for example, whereas if you have a low chance, you may choose not to go ahead," Chevenix-Trench said.

"These are practical decisions that are being made all the time by women. One of the things we need to find out is how much these decisions would be altered by this information."

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