Medicineworld.org: New genetic links to ovarian cancer risk
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New genetic links to ovarian cancer risk
An international consortium of researchers has discovered new genetic variants in five regions of the genome that affect the risk of ovary cancer in the general population, as per two separate studies published recently (Sunday), online in Nature Genetics
The scientists have now found additional stretches of DNA on chromosomes 2, 3, 8, 17 and 19 after grouping patients as per the type of ovary cancer they had developed. Four out of five of the new DNA variations were more common in women who had developed the most common and aggressive form of disease, known as serous ovary cancer.
Andrew Berchuck, MD, professor of gynecologic oncology at Duke University Medical Center and head of the steering committee of the international Ovarian Cancer Association Consortium (OCAC), says the associations of these genetic variants with ovary cancer were discovered using genome-wide association studies (GWAS).
"Since the critical validation of these findings waccording toformed by a large consortium of researchers from around the world, we see this research as a triumph of science without borders for the benefit of women everywhere."
Ovary cancer is the fifth most common cancer among women in developed countries, and often detected in later stages when the chances of cure are small. As a result, the disease claims more lives in the U.S. than all other gynecological cancers combined. Every year, about 13,000 women in the U.S. and 130,000 worldwide die from the disease.
"These latest findings raise the possibility that in the future, women in the general population who are at the greatest risk of developing ovary cancer because they carry these newly discovered DNA variants can be identified and given closer surveillance to look for early signs of ovary cancer when it is most treatable," says Berchuck. "It also suggests that preventive approaches could be targeted towards these women."
Ellen Goode*, PhD, a genetic epidemiologist at the Mayo Clinic College of Medicine and the main author of one of the studies, says "additional research will be mandatory to learn more about the specific genes and DNA changes in these DNA stretches that could be causing ovary cancer," but she says the newly implicated regions of the genome also contain some familiar suspects.
"Common genetic 'typos' at 8q24 have already been shown to render some people vulnerable to prostate, colorectal, breast and bladder cancers, so it's not too surprising that there appears to be something there correlation to ovary cancer," Goode said. "What is surprising is that we observed that three of the most common SNPs for ovary cancer lie quite a distance away from this bunch of troublemakers in an apparent gene desert which suggests they appears to be causing functional problems by a very different mechanism".
A second study** in the same issue of Nature Genetics found a region of DNA on chromosome 19 that also affects ovary cancer risk. And a third study in the same issueobserved that variation in this same region of chromosome 19 also increases the risk of breast cancer in women who already carry a faulty copy the BRCA1 gene*** on chromosome 17.
Scientists 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 ovary cancer, but these mutations only account for a small percent of ovary cancers. Because DNA variations such as those described in these new studies are much more common in the general population than BRCA1 and BRCA2, scientists conclude that they probably cause a much greater proportion of all ovary cancers, even though the overall cancer risks linked to these SNPs are smaller.
Simon Gayther, PhD, Professor of Preventive Medicine at the University of Southern California and senior author of the second ovary cancer study, said: "Our study shows that the same genetic region plays a role in both breast and ovary 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 ovary cancers".
Paul Pharoah, PhD, of Cancer Research UK Center for Genetic Epidemiology at Cambridge University and a senior author on both studies, says, "I believe that the most important message women can take away from this work is that we are making progress in understanding ovary 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 ovary cancer and respond with appropriate prevention and therapy options."
The findings may represent the tip of the iceberg, as per Georgia Chenevix-Trench, PhD, from the Queensland Institute of Medical Research in Australia, who led development of a consortium dedicated to studying the outcomes linked to BRCA1 and BRCA2 mutations. She said future research may yield additional genetic regions that alter a woman's risk of ovarian and other cancers.
Posted by: Emily Source
Did you know?
An international consortium of researchers has discovered new genetic variants in five regions of the genome that affect the risk of ovary cancer in the general population, as per two separate studies published recently (Sunday), online in Nature Genetics The consortium, including researchers from the U.S., Europe, Canada and Australia, based the new work on their earlier research comparing 10,283 women with ovary cancer to 13,185 women without the disease. That effort had found a stretch of DNA on chromosome 9 containing single DNA letter variations (SNPs) linked to ovary cancer risk.
Medicineworld.org: New genetic links to ovarian cancer risk
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