Breast Cancer Breakthrough
HOPE FOR NEW TREATMENTS AFTER SCIENTISTS UNCOVER DETAILED PICTURE OF GENETIC EVENTS THAT CAUSE IT
Largest ever study uncovered 5 new genes associated with breast
Could lead to more personalised treatments for patients in the future
Breast cancer’s secrets have been cracked by scientists, who say they have a near perfect picture of the genes at the heart of the disease. The landmark research paves the way for new and better treatments – as well as ways of preventing the disease ever occurring.
In future, doctors could use ‘genetic x-rays’ to decide on the best drugs for each individual patient. The researchers, from the renowned Wellcome Trust Sanger Institute near Cambridge, said their study, the biggest of its kind, marks a ‘very significant moment for cancer research’. Breast cancer is caused by the DNA in the cells in a woman’s breast tissue gathering more and more mutations as she gets older. Eventually, the damage is too great for her body to contain, and a tumour forms. To find out more, an international team of scientists spent seven years peering deep into the DNA of breast tissue samples from 560 patients from around the world. Most come from women but a handful were from men. By capitalising on advances on technology, they were able to read each of the 3 billion letters that made up each person’s genetic code.
This uncovered 93 genes, that if mutated, can cause breast tumours. Some had been discovered before, but with the new editions, this is expected to be a near definitive list.
Sanger director Professor Sir Mike Stratton said: “In the latter part of the last century, we were able to identify the first individual genes that became mutated. “Now, with our ability to sequence the whole genome of very large numbers of cancers, we’re essentially moving to a more or less complete list of these mutated cancer genes, so it’s a very significant moment for cancer research.’
Crucially, each of these genetic errors is a weakness that could be exploited by new drugs. While some medicines, such as
breast cancer ‘wonder drug’ Herceptin, are already matched to a woman’s DNA, doctors want to be able to give every woman customised treatment. Researcher Dr Serena Nik-Zainal said: “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 is a step closer to personalised healthcare for cancer.”
Sir Stratton said: “This is no longer speculation or hand-waving.
“This huge study… shows it is possible to sequence individual cancer genomes and this should lead to benefits for patients.” The research, published in the journal Nature and Nature Commu
nications, could also shed light on what causes the mutations, and so causes cancer.
The scientists identified 20 different patterns of mutation thought to have separate causes. One was left by the BRCA1 gene, which is carried by actress Angelina Jolie, and greatly increases a woman’s odds of breast cancer. But the origins of many of the other patterns remain a mystery. Working out what food, drink, habit or other factor triggers the changes could lead to new ways of preventing the disease.
For instance, if a particular chemical is found to be sinister, women could be told to avoid it, in the same way as they are advised to quit smoking to cut their odds of lung cancer and wear sunscreen to protect themselves against skin cancer.
Excitingly, the team turn the vast amount of information into a ‘genetic x-ray’ – an easy to read report.
This is vital if the vast amount of information generated by genetic analysis is to be of practical benefit to patients. However, the researchers cau- tioned that drugs based on today’s findings could take decades to develop and even then, they may not always work. “Cancers are devious beasts and they work out ways of developing resistance to new therapeutics.
“Overall, I’m optimistic but it’s a tempered optimism,” the researchers said. Dr Emma Smith, of Cancer Research UK, said: ‘This study brings us closer to getting a complete picture of the genetic changes at the heart of breast cancer and throws up intriguing clues about the key biological processes that go wrong in cells and drive the disease. ‘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.’
Breast cancer is caused by the DNA in the cells in a woman’s breast tissue gathering more and more mutations as she gets older. This study brings us closer to getting a complete picture of the genetic changes at the heart of breast cancer and throws up intriguing clues about the key biological processes that go wrong in cells and drive the disease Dr Emma Smith Cancer Research, UK
Scientist from Cambridge-based Wellcome Trust Sanger Institute revealed what genetic variations exist in breast cancers and where they occur in the genome.
The research, published in the journal Nature and Nature Communications, could also shed light on what causes the mutations, and so causes cancer.