Scientists work to unravel genetics of Cancer

By ahhb
Tuesday, 20 January, 2015

Head of QIMR Berghofer’s Cancer Program Professor Georgia Chenevix-Trench says scientists are playing a major role in the international effort to unravel the genetics of cancer - research with enormous importance for patients around the globe.

The research world has made remarkable advances in our understanding of cancers in the last 30 years, and the last 10 have been particularly exciting.
QIMR Berghofer is part of an international collaboration which has now identified more than 150 regions of the genome that can increase a person’s risk of breast, prostate and ovarian cancer.
The International Collaborative Oncological Gene-environment Study (iCOGS) of more than 200,000 people could lead to new treatments, targeted screening and a greater understanding of how the cancers develop.
This global effort has gone beyond gene discovery to providing a much better understanding of how cancer genes function – a major step forward in the battle to find new treatments. The study is looking for ‘typographical errors’ – called single nucleotide polymorphisms (SNPs) – that flag the presence of nearby genes, or genetic switches, which may increase the risk of developing cancer.
By studying the DNA makeup of more than 100,000 people with cancer and 100,000 without, the scientists found ‘typos’ which were more common in people with breast, prostate or ovarian cancers.
By themselves, each of these typos increases the risk of cancer by a very small amount. However, to use breast cancer as an example, women who have a large number of these typos are three times more likely to develop the disease than women who carry an average number.
Researchers have identified more than 90 SNPs for breast cancer, more than doubling the number found in previous studies. They were found in regions that have been linked to other cancers, suggesting a shared underlying mechanism that can cause cancer.
Scientists already knew that women with the BRCA gene faults are at greater risk of breast and ovarian cancers. This new study has established that the 5% of the women who carry the BRCA1 or BRCA2 fault also have many of the ‘typos’. As a result they have more than an 80% chance of developing breast cancer by the time they turn 80.
By using this genetic information, iCOGS scientists are on the verge of developing tests to complement existing breast screening, to identify those people at greatest risk. This step would bring information from the study into the clinic so that women with typos in BRCA1 or BRCA2 can be given their individual risk rating.
The international collaboration has found also 26 genetic typos for prostate cancer, but believe this is just the tip of the iceberg and there could be more than 2000 regions that influence a man’s chance of getting the disease.
This suggests further research will provide fresh insights into similarities between different cancers.

“The International Collaborative Oncological Gene-environment Study of more than 200,000 people could lead to new treatments, targeted screening and a greater understanding of how the cancers develop.”

Professor Georgia Chenevix-Trench

Professor Georgia Chenevix-Trench is a NHMRC Senior Principal Research Fellow and head of the cancer program at QIMR Berghofer Medical Research Institute. She is also the conjoint Professor in the Division of Health Sciences at the University of Queensland. She holds a BA (Hons) from the Department of Genetics at Trinity College in Ireland, and was awarded a PhD in 1985 from the Department of Human Genetics at the Medical College of Virginia in USA. Professor Chenevix-Trench chairs the Executive Committee of kConFab, the national consortium for research into familial breast cancer. She is a founding member of the Breast Cancer Association Consortium which published the first genome-wide association study for breast cancer.