ISLAMABAD: A new genomic study suggests that 12 genetic variants increase the chances of developing ovarian cancer. International team of scientists from United Kingdom, USA and Australia identified 12 genetic variations that raises the chance of epithelial ovarian cancer. OncoArray Consortium, a network for understanding the genetic architecture of common cancer, used a genotyping technique that allowed the researchers to identify nearly 500,000 single nucleotide polymorphisms (SNPs), which are the most common type of variation found in the human genome. “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,” explains Professor Paul Pharoah from the University of Cambridge, UK. “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,” he added. More than 31,000 people were investigated who had the BRCA1 and BRCA2 genetic mutations and almost 4,000 had EOC. The researchers identified 12 new genetic variants associated with EOC risk. Additionally, the new study confirmed 18 previously identified variants that had been linked to the risk of developing EOC. Overall, 6.5 percent of the inherited genetic risk of developing EOC is now known. Dr. Catherine Phelan from the Moffitt Cancer Center in Tampa, USA, explained, “Ovarian cancer is clearly a very complex disease – even the 30 risk variants that we now know increase risk of developing the disease account for just a small fraction of the inherited component.” “We believe that there will likely be many more genetic variants involved, each with extremely small effects. Most of these are likely to be common, but some will be rare,” she added. The authors pointed that some women have multiple risk-associated gene variants. However even if combined, these still do not account for more than 2.8 percent chance of developing ovarian cancer in their lifetimes. Moreover, Patients who are offered to have their ovaries surgically removed as a preventive measure, have a lifetime risk of minimum 10 percent. However, these variants also affect the risk of ovarian cancer in women who carry a fault in the BRCA1 or BRCA2 genes and this might be sufficient to call for preventive surgery. Dr Simon Gayther from Cedars-Sinai Medical Center, Los Angeles, USA, said, “In some ways, the hard work starts now. We really have little idea of the functional effect these variants have at the molecular or cellular level and so there are few clues as to how they might affect risk. If we can understand how they work, we will be in a better position to treat – and possibly prevent – ovarian cancer.”