Scientists say they now have an almost clear picture of the genetic events that lead to breast cancer.
The study was published in Nature.
The new study, the largest of its kind, has been described as a “milestone” moment that could help discover new ways of treating and preventing breast cancer.
Cancer Research UK said the findings of the new study would pave the way to finding new drugs for treating cancer.
Under the study, the research team looked at all 3 billion letters of people’s genetic code in 560 breast cancers.
The researchers found that 93 sets of instructions, or genes, if mutated, can cause tumours.
Scientists now expect this to be the definitive list, except a few rare mutations.
Complete View Of Breast Cancer
Prof Sir Mike Stratton, the director of the Sanger Institute in Cambridge which led the study, told the BBC,
“There are about 20,000 genes in the human genome. It turns out, now we have this complete view of breast cancer – there are 93 of those [genes] that if mutated will convert a normal breast cell into a breast cancer cell. That is an important piece of information.
“We hand that list over to the universities, the pharmaceuticals, the biotech companies to start developing new drugs because those mutated genes and their proteins are targets for new therapeutics.
“There are now many drugs that have been developed over the last 15 years against such targets which we know work.”
Patients with specific mutations are already using drugs such as Herceptin.
Prof Stratton expects new drugs will still take at least another ten years to reach patients. He said,
“Cancers are devious beasts and they work out ways of developing resistance to new therapeutics so overall I’m optimistic, but it’s a tempered optimism.”
The study revealed that 60% of the genetic mutations that lead to cancer are found in just 10 genes.
The team was able to identify 12 types of damage that cause mutations in the breast, with the help of the unique scars left by mutations, known as mutational signatures on our DNA.
Most of these mutations are still unexplained.
Researchers hope that the findings could finally lead to ways of reducing the risk of cancers.
Dr Serena Nik-Zainal, another researcher at the Sanger Institute, added,
“In the future, we’d like to be able to profile individual cancer genomes so that we can identify the treatment most likely to be successful for a woman or man diagnosed with breast cancer.
Dr Emma Smith, from Cancer Research UK, said,
“Understanding these underlying processes has already led to more effective treatments for patients, so genetic studies on this scale could be an important stepping stone towards developing new drugs and boosting the number of people who survive cancer.”