Dozens Of New Genetic Markers For Cancer Risk Identified But Thousands More Remain

A large international study has identified more than 80 genetic markers for cancer risk, but researchers suggest that this is just the tip of the iceberg.

AsianScientist (Apr. 3, 2013) – A large international collaboration has identified more than 80 genetic markers that are linked to increased risks for developing three types of cancer, but researchers believe there may be thousands more that have yet to be uncovered.

These findings were released by the Collaborative Oncological Gene-environment Study (COGS) and published simultaneously in at least twelve articles in the current issues of Nature Genetics, Nature Communications, American Journal of Human Genetics, PLoS Genetics, and Human Molecular Genetics.

The study is an international effort to identify genetic markers, known as single nucleotide polymorphisms (SNPs), that make certain people more susceptible to developing prostate, breast, and ovarian cancers. The collaboration includes more than 160 research groups from all over the world.

In total, the researchers studied the DNA of more than 100,000 cancer patients around the world and another 100,000 people from the general population, identifying 83 novel genetic markers that were linked to increased risk of cancer.

For breast cancer the researchers found 49 SNPs, more than doubling the number that had previously been found. Notably, some of these SNPs were found in regions that had been linked to other cancers, suggesting that these cancers may have a common genetic cause.

In the case of prostate cancer, 26 novel SNPs were found, bringing the total number of genetic markers to 78. For ovarian cancer nine new SNPs were identified in the study.

Although each marker is associated with a very small change in risk of cancer, one percent of the general population have a large proportion of these errors. Compared to people who have an average number of these markers, people who belong to this “at risk” population are five times more likely to develop prostate cancer and three times more likely to develop breast cancer.

The researchers hope that these findings will help to pinpoint the causes behind these cancers and also identify the people most at risk of developing these cancers.

“We’re now on the verge of being able to use our knowledge to develop tests that could complement breast cancer screening and take us a step closer to having an effective prostate cancer screening program,” says Professor Doug Easton, who led several studies within the collaboration.

However, researchers suggest that this is just the tip of the iceberg and there could be more than 1,000 such markers that could influence a person’s chance of developing these cancers.

“An equally important finding is that we identified how many additional SNPs that could influence the risk of breast cancer and prostate cancer, respectively. For breast cancer the number is 1,000 and for prostate cancer 2,000,” says Professor Per Hall, the coordinator of the COGS consortium.

The main articles from the study can be found at:

Eeles et al. (2013) Identification Of 23 New Prostate Cancer Susceptibility Loci Using The iCOGS Custom Genotyping Array.

Pharoah et al. (2013) GWAS Meta-analysis And Replication Identifies Three New Susceptibility Loci For Ovarian Cancer.

Bojesen et al. (2013) Multiple Independent Variants At The TERT Locus Are Associated With Telomere Length And Risks Of Breast And Ovarian Cancer.

Garcia-Closas et al. (2013) Genome-wide Association Studies Identify Four ER Negative–specific Breast Cancer Risk Loci.

Michailidou et al. (2013) Large-scale Genotyping Identifies 41 New Loci Associated With Breast Cancer Risk.


Source: COGS.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Yew Chung is a postdoctoral research fellow at the Duke-NUS Graduate Medical School, Singapore.

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