An international effort involving more than 200 research groups and over 1,000 scientists has led to the discovery of 80 new genetic markers that lead to cancer, more than doubling the knowledge of the number of genes linked to these diseases.
The research, funded mainly by Cancer Research UK, the European Union and US National Institute of Health, investigated the role of mutations in different DNA strands and the genetic markers that can cause the hormone related diseases: breast, prostate and ovarian cancer.
The CEO of Cancer Council Australia, Professor Ian Olver, said that the study had identified the tip of the iceberg.
“Cancer needs to be triggered by several genetic mutations. The hope is that these findings will help us use these genetic markers for early detection and eventually develop genetic tests that could screen for risk.”
“Over time we could develop genetic tests to look at the pattern of genes to determine how aggressive the cancer could be, which would open up the potential for better screening and more effective treatment.”
The report, the Collaborative Oncological Gene-Environment Study, involved the Queensland Institute of Medical Research, the University of Melbourne and the Cancer Council of Victoria.
The University of Melbourne and the Cancer Council of Victoria provided 7,500 DNA samples, around two-thirds of the Australian contribution to the study. Over 100,000 cancer patients and 100,000 members from the general population participated in the study, providing an extensive collection of test subjects.
The discovery of 80 new genetic markers significantly increases the number of mistakes in a person’s DNA that doctors and scientists could soon be able to recognise, leading to the identification of more genetic markers that may increase the risk of disease.
The genetic makeup of 25,000 prostate cancer patients was compared to a similar number of unaffected men. Scientists were able to pinpoint 23 new faults in DNA that heighten the chance of developing prostate cancer, while 16 of these genetic markers can actually lead to the most life-threatening and aggressive forms of the disease.
While one in nine Australian men will develop prostate cancer, the study revealed that of the one per cent of men who had the most genetic faults, one in two would develop prostate cancer. This is more than five times the national average.
Research fellow at the Victorian Cancer Council’s Cancer Epidemiology Centre, Dr Liesel Fitzgerald, said that it was an exciting time for international and Australian scientists.
“We can now explain about 30 per cent of genetic markers that lead to prostate cancer. With the 23 newly discovered genetic faults and the 55 that we already knew about, we can now identify specific genetic variants and can see what these changes in DNA mean, allowing us to attribute a function to these genetic faults.”
Researchers more than doubled the number of genetic markers for breast cancer to 49. Women who were found to have most of these genetic markers had a 30 per cent risk of developing breast cancer, which is three times the national average.
The research revealed that women who have a mutation in the BRCA gene, already facing a risk of 65 per cent, are 80 per cent more likely to develop breast cancer if they carry some of the newly discovered genetic faults.
Possibly the least known type of cancer, ovarian cancer, formed the last part of the study. Although uncommon compared to prostate and breast cancer, ovarian cancer is still the sixth leading cause of cancer related death among Australian women. The study found eight new genetic markers for ovarian cancer, adding to the
previous four.
