Diether Lambrechts (VIB/KU Leuven): “The results of this international collaboration demonstrate how complex cancer is. Hundreds of genes play a role in the development of cancer. Understanding why some people have a greater risk of cancer than others is very important. It opens up perspectives to reduce their risks of cancer in the future or to attack the disease at the earliest stage and thereby increasing their chances of survival.”
Looking for the difference between diseased and healthy
Scientists in more than 40 countries searched for genetic variations – so-called “single nucleotide polymorphisms (SNPs)” – that result in an increased risk of cancer. They compared the DNA of 100,000 cancer patients to the DNA of 100,000 healthy people. They found SNPs in DNA that were more common in people with prostate, breast or ovarian cancer. A single SNP results in a minimal increase in the risk of cancer. However, the scientists found that some people have many of these SNPs and when combined they increase the risk of prostate or breast cancer several times.
Control over crucial genes
Many of the newly identified high-risk SNPs are located in DNA regions that control the behavior of genes. These SNPs can disrupt the control and thereby contradict the “brake signals” that give cells the signal to stop growing. Further research into how these genes are involved in cancer is important to gain a better understanding of the development of cancer and thereby generate new insights into the treatment of cancer.
Estimating the risk of breast and ovarian cancer
The scientists found 49 SNPs that increase the risk of breast cancer. Some of these SNPs are located in regions that are also involved in other cancers. This indicates that they could affect a more general mechanism in the development of cancer. A total of 9 new SNPs were identified for ovarian cancer.
The consortium examined the extent to which certain SNPs affect the risk of cancer in people with errors in the known BRCA breast cancer genes. Women with a mutation in a BRCA gene know that they have an increased risk of developing breast or ovarian cancer. However, it is not yet clear what leads to them actually developing cancer. The scientists discovered that women with BRCA mutations and certain SNPs are almost certain to develop breast cancer before they turn 80. Further research should result in much better screening techniques.
More targeted screening for breast and prostate cancer
A total of 26 new SNPs were identified for prostate cancer, 20 of which that are associated with the disease in its most aggressive and life-threatening form. This allows scientists to set up tests to identify men with a very high risk of prostate cancer. By screening this group at very regular intervals, this could have a large impact on the number of men that die as a result of prostate cancer. This figure is currently 1 in 6. The plan is to use this new information to optimize the tests for prostate cancer with the aid of genetic screening. In the long term, a similar approach can also be implemented to predict breast cancer more accurately.
A unique collaboration
These results are published in 12 scientific articles in various leading journals such as Nature Genetics, Nature Communications and The American Journal of Human Genetics. They were published simultaneously. Such a co-coordinated simultaneous publication is exceptional and indicates the importance of the findings.