More than 80 genetic “spelling mistakes” that may indicate an increased risk of breast, prostate, and ovarian cancers were revealed in the findings of a large, international research study within the framework of the European Union (EU) Network Collaborative Oncological Gene-environment Study (COGS). For the first time, researchers have a relatively clear picture of the total number of genetic alterations that can be linked to these cancers. Ultimately they hope to be able to calculate the risk of individual cancers, to better understand how they develop and to be able to tailor new treatments.
The main study findings are published in a special issue on genetic risk factors for cancer in the prestigious scientific journal Nature Genetics. Originating from COGS, an EU-based consortium that includes more than 160 research groups from all over the world, the studies included 100,000 patients with breast, ovarian, or prostate cancer and 100,000 healthy participants from the general population.
The scientists performed genetic analyses on all study participants. The composition of the nitrogen bases A, G, C and T was studied on 200,000 selected sections of the DNA strand. When cancer patients had significantly different compositions compared with healthy control subjects, the differences were considered to be relevant to risk of disease. The alterations can be described as a genetic spelling mistake, where A, G, C, or T have been replaced with another letter. This spelling mistake is called single nucleotide polymorphism (SNP, pronounced “snip”).
For breast cancer, the researchers found 49 genetic typos or SNPs, which is more than double the number previously found. In the case of prostate cancer, researchers discovered another 26 deviations, which means that a total number of 78 SNPs may be linked to the disease. For ovarian cancer, eight new relevant SNPs were found.
“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,” said Professor Doug Easton, PhD, of the University of Cambridge, United Kingdom, who has led several of the presented studies.