http://www.digitaljournal.com/tech-and-science/science/major-study-reveals-12-new-variants-for-ovarian-cancer/article/489002

Major study reveals 12 new variants for ovarian cancer

Posted Mar 28, 2017 by Tim Sandle
A review of 100,00 samples of DNA taken from 17,000 patients has revealed 12 new genetic variants of ovarian cancer. This suggests the disease is more complex, and potentially harder to treat, than previously known.
The discovery of the 12 new variants suggests that there is an increased risk of developing the disease and the 12 will be added to the18 of the previously known variants. The discovery has come from the OncoArray Consortium and the samples were provided from U.K., the U.S. and Australia. In all some 418 international researchers were involved in what turned out to be a mammoth DNA screening project.
Ovarian cancer is a cancer that forms in an ovary. The cancer leads to abnormal cells forming, which have the ability to invade or spread to other parts of the body. Symptoms can include bloating, pelvic pain, abdominal swelling, and loss of appetite. Most cases are epithelial ovarian cancer and the peak rate of cases is among women aged 75-79 years old.
A pathological specimen of ovarian carcinoma.
A pathological specimen of ovarian carcinoma.
Wikipedia
Commenting on the research, one of the leads, Paul Pharoah, from the University of Cambridge, told Bioscience Technology why genetic screening was important: “We know that a woman's genetic make-up accounts for about one third of her risk of developing ovarian cancer. This is the inherited component of disease risk.” The genes responsible for triggering this type of cancer include BRCA1 and BRCA2, which account for about 40 per cent of the inherited component. Variants common in the population (carried by around one in 100 people) are likely to account for most of the rest of the inherited component of risk. The 12 new genetic variants relate to these other genetic causes.
With the new research the OncoArray Consortium tested the genomes of over 25,000 people with epithelial ovarian cancer. These were compared with some 41,000 healthy controls. With these data sets the researchers also analyzed results from a further 31,000 BRCA1 and BRCA2 mutation carriers. This set included around 4,000 epithelial ovarian cancer patients. This screening led to the 12 new variants. This means there now 30 risk variants and these variants account for 6.5 percent of the inherited component of risk.
Genetic risk does not necessarily mean that cancer will develop, for environmental factors also play a part. Raising the impact of the environment upon genetics, Dr. Pharoah: “We're less certain of environmental factors that increase our risk, but we do know that several factors reduce the risk of ovarian cancer, including taking the oral contraceptive pill, having your tubes tied and having children."
The discovery has been published in the journal Nature Genetics. The paper is titled “Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.”