Tuesday May 3 2016
Scientists have mapped genes linked to breast cancer
"Breast cancer treatment breakthrough after 'milestone' genetic discovery," says The Independent, about widely reported research investigating genetic mutations in people with breast cancer.
The researchers took samples of cancer cells from 560 people with breast cancer (556 women and four men). They compared the DNA from the cancerous cells with DNA from normal cells.
They found 93 genes that had mutated in the cancer cells and concluded that they could have caused normal tissue to become cancerous. They also found 12 genetic patterns linked with breast cancer.
These findings have been called "groundbreaking" in the media. While they are certainly interesting, it's important to remember that, even if the gene is present, it doesn't mean the person will get cancer, just that their risk is increased.
It's hoped that the study will lead to more personalised treatments for breast cancer, similar to drugs used for other DNA mutations that are already known.
If there is a history of breast cancer in your family, you may be worried about your own risk. It's best to visit your GP, who can assess you and refer you to a genetic clinic if necessary.
Where did the story come from?
The study was carried out by researchers from a number of institutions, including the Wellcome Trust Sanger Institute, East Anglian Medical Genetics Service, and the Cambridge University Hospitals NHS Foundation Trust.
Funding for the study was provided by multiple organisations, including the European Community's Seventh Framework Programme, the Wellcome Trust and the Institut National du Cancer (INCa) in France. The ICGC Asian Breast Cancer Project was funded through a grant from the Korean Health Technology R&D Project, Ministry of Health and Welfare, Republic of Korea.
The study was published in the peer-reviewed scientific journal Nature.
These findings have been reported accurately in the media. It's good to see explanations stating that, while this may be an important discovery, it may still be decades before targeted treatments become available. One of the researchers told the media: "Overall, I'm optimistic, but it's a tempered optimism".
What kind of research was this?
This was a laboratory study, which aimed to gain a better understanding of genetic mutations that lead to breast cancer.
The researchers hope, by establishing a clear picture of the particular mutations and their causes, it may be possible to find ways to prevent them happening, or target treatment more effectively.
Professor Sir Mike Stratton, Director of the Wellcome Trust Sanger Institute and one of the research team, says: "This huge study, examining in great detail the many thousands of mutations present in each of the genomes of 560 cases, brings us much closer to a complete description of the changes in DNA in breast cancer and thus to a comprehensive understanding of the causes of the disease and the opportunities for new treatments."
What did the research involve?
The research included 560 people with breast cancer, comprising 556 women and four men. Researchers took samples from the cancer itself and surrounding tissue. These samples were analysed and only those with more than 70% tumour cells were included in the study.
The research involved identifying the sequence of each gene, the impact of mutations and the variation of the mutation rate across genes.
The genes were also analysed for "mutational signatures", or genetic patterns, associated with breast cancer. These were compared to genetic patterns that have already been identified.
What were the basic results?
The genetic analysis of the breast cancer samples identified 93 genes which, if they mutate, could cause breast cancer. Five of these genes (MED23, FOXP1, MLLT4, XBP1 and ZFP36L1) were previously unknown. There were 10 genes that were particularly likely to mutate and which led to 62% of cancers.
The team identified 12 genetic patterns linked to breast cancer, and another seven related to other cancer types.
How did the researchers interpret the results?
The researchers identified 12 genetic patterns relating to cancer and 93 genes. They say there may be others, but those most commonly linked with breast cancer are now known.
The team believes important questions remain and more research is needed in this area to complete our understanding.
This study looked at genetic mutations in people with breast cancer. The researchers found 93 genes that, if mutated, can make normal tissue become cancerous. They also found 12 genetic patterns or "mutational signatures" associated with the disease.
These findings have been reported in the media as a breakthrough, with one media outlet saying that this, "landmark research paves the way for new and better treatments – as well as ways of preventing the disease ever occurring".
While these findings are exciting, it's important to remember that, even if the gene is present, it doesn't mean the person will get cancer, just that their risk is increased.
More research is needed and it will take a number of years before any new treatments or guidance on how we can prevent the cancer to begin with become available. This research focused on the genetics of breast cancer and future work may look at other cancer types.
There are a number of genes that have already been identified as increasing a person's risk, but it doesn't mean that people with these genes will definitely develop cancer. You can reduce your risk of breast cancer by limiting your alcohol intake, maintaining a healthy weight and keeping physically active.
If there is a history of breast cancer in your family, you may be worried about your own risk. It’s best to visit your GP, who can assess you and refer you to a genetic clinic if necessary.