Researchers have known for some time that heritable mutations in the BRCA1 and BRCA2 genes can dramatically increase a woman's chances of developing breast and ovarian cancer, but these mutations only account for a small percent of ovarian cancers. Because DNA variations such as those described in these new studies are much more common in the general population than BRCA1 and BRCA2, researchers conclude that they probably cause a much greater proportion of all ovarian cancers, even though the overall cancer risks associated with these SNPs are smaller.

Simon Gayther, PhD, Professor of Preventive Medicine at the University of Southern California and senior author of the second ovarian cancer study, said: "Our study shows that the same genetic region plays a role in both breast and ovarian cancer, suggesting that the same faulty pathway can cause both diseases, just like BRCA1 and BRCA2 do. This is important because it suggests that women who carry certain versions of this stretch of DNA could benefit from closer monitoring for both breast and ovarian cancers."

Paul Pharoah, PhD, of Cancer Research UK Center for Genetic Epidemiology at Cambridge University and a senior author on both studies, says, "I think that the most important message women can take away from this work is that we are making progress in understanding ovarian cancer."

"We are slowly but clearly leading toward a time when we will be able to draw an individualized profile of a woman's risk of ovarian cancer and respond with appropriate prevention and treatment options."

The findings may represent the tip of the iceberg, according to Georgia Chenevix-Trench, PhD, from the Queensland Institute of Medical Research in Australia, who led development of a consortium dedicated to studying the outcomes associated with BRCA1 and BRCA2 mutations. She said future research may yield additional genetic regions that alter a woman's risk of ovarian and other cancers.

Source: Duke University Medical Center