Cancer Research UK-funded scientists from the University of Cambridge looked at the seven common 'modest risk' gene sites which, in combination, put women at increased risk of developing breast cancer. They wanted to see what impact testing women for these genes might have on future public health policy - such as lowering or increasing the age at which they start to be screened for breast cancer and targeting lifestyle advice to women to reduce their risk of developing the disease.
Study author Dr. Paul Pharoah from the University of Cambridge said, "We are a few years away from a new and powerful range of genetic tests for breast cancer. We believe genetic testing has the potential to enable doctors to identify a woman with an increased risk of breast cancer who would benefit from mammography at an early age or woman who may benefit from regular MRI scanning as well. This approach would also identify a 55-year-old woman with a low chance of breast cancer who possibly wouldn't need such regular checks."
Currently doctors only test women who have a very strong family history of breast cancer for the high risk breast cancer genes such as BRCA1, BRCA2, PTEN, and TP53. But these gene faults are rare and few women in the general population will benefit from such testing.
In contrast, genes that give woman a slightly increased risk are common and although each one has little impact alone, testing for their combination could prove useful.
"It is very exciting to see workable and affordable approaches to genetic screening for breast cancer on the horizon. We expect such technology to develop very fast in the next decade so it's important that we start thinking about how best to apply these advances," said lead author Professor Sir Bruce Ponder, director of the Cancer Research UK Cambridge Research Institute at the University of Cambridge.
"This study marks the potential for a tailor-made approach to screening for breast cancer which could radically change who we target and how we detect early signs of the disease. Great progress has been made to improve our understanding of the ways in which certain genes affect the risk of breast cancer - and as scientists find even more of these 'risk genes,' our ability to use genetic tests to identify a woman at risk will improve,” said Dr. Lesley Walker, director of cancer information at Cancer Research UK. “But there is still some way to go before this kind of profiling becomes a reality."
Some people are born with a fault in one of their genes. This does not mean that they will definitely develop cancer, but it does mean that fewer other things need to go wrong for disease to develop. Doctors say people with a fault in certain genes are more likely to get cancer or have a genetic predisposition to the disease.
Women who have a very strong family history may have a faulty gene or genes in their family that increases their risk of breast cancer. There are number of faulty genes that have been shown to increase breast cancer risk. But, so far, doctors only test for four genes—BRCA1, BRCA2, TP53 and PTEN—as these are associated with high risks of developing cancer.
Illustration: Mammogram showing breast cancer (indicated by arrow). Wikipedia.
University of Cambridge News Release (06/26/08)
Cambridge Research Institute News Release (06/26/08)
Medical News Today (06/27/08)
Abstract (The New England Journal of Medicine, Volume 358, No. 26, 2796-2803, June 26, 2008)