People in England will have access to DNA tests on an unprecedented scale from the autumn when the National Health Service (NHS) becomes the first health service in the world to routinely offer genomic medicine. The Guardian reports that from 1 October, hospitals across England will be connected to specialist centres that read, analyse and interpret patient DNA to help diagnose rare diseases, match patients to the most effective treatments, and reduce adverse drug reactions.
The move marks a big step towards “precision medicine”, which offers more efficient therapies that are tailored to individual patients.
The report says under the service, new cancer patients will routinely have their tumour DNA screened for key mutations that can point doctors towards the best drug to use in treatment, or to clinical trials of experimental therapies that patients are likely to benefit from.
For some diseases, such as leukaemia, sarcoma and childhood malignancies, doctors will have the cancer’s whole genome sequenced to identify the suite of mutations that drive their growth. Similarly broad sequencing will be available for medical staff caring for babies and children who are admitted to intensive care without an existing diagnosis.
Beyond its aim to bring patients the most effective treatments faster, the service is expected to generate a wealth of data on the interplay between DNA, health and lifestyles, which will become a powerful tool for research into cancer and other diseases.
The report says the genomic medicine service will launch in England initially, but discussions are under way with the devolved regions about how they might become involved. “We are ushering in a new era of genomic health,” said Mark Caulfield, the chief scientist at Genomic England and professor of cardiovascular genetics at the William Harvey Research Institute in London. “This is a big step and it grows over the new two years. It’s a total transformation.”
The NHS already provides some genetic tests but uptake has been patchy and depended on regional expertise, leading to stark differences in the tests available across the UK.
“This will really look to address that. It won’t matter if you live in the north east (of England) or the south west, you should have the same access to clinical genome testing and that’s a great thing,” said William Newman, professor of translational genomic medicine at Manchester University and vice-chair of the British Society for Genetic Medicine.
The report says the service will build on foundations laid down by the 100,000 Genomes Project, a huge DNA sequencing effort run by Genomics England, a company formed by the Department of Health in 2013. So far, the scientists have read more than 70,000 whole genomes of people with cancer or rare genetic diseases and expect to reach their target by the end of the year.
The project swiftly established that the standard surgical practice of preserving tumour biopsies in a solution of formaldehyde played havoc with DNA. To read the genetic makeup of a cancer the tissue must be fresh-frozen, a change of procedure that is steadily being adopted by surgeons.
The report says Genomics England has set up seven genomic hubs across the country to deliver DNA tests on cancer, rare diseases and other conditions. A separate lab in Cambridge will perform whole genome sequencing when all 3.2bn letters of the human DNA code are needed. Because DNA test results are often complex, 13 national genomic medicine centres will draw on multidisciplinary teams of specialists to work through results and write reports for patients. Details of available tests will be stored in a national directory that will be updated every year as genetic medicine advances.
Genetic medicine has already transformed the treatment of some cancer patients. The drug Herceptin was developed to knock out proteins called HER2 receptors that make some breast cancers grow faster. It takes a quick gene test to identify patients most likely to benefit. “It shows in a nutshell the elegance and the potential of targeted therapies,” said Louise Jones, professor of breast pathology at Barts Cancer Institute in London.
Currently, lung cancers are screened for a handful of mutations that make them susceptible to different drugs. But recent research suggests that simply knowing how many mutations a tumour carries is the best guide to how well it will respond to immunotherapy, which unleashes the body’s natural defences on the cancer. Over time, small, specific tests may become obsolete. “Gradually, through economies of scale we believe it will make sense to do whole genome sequencing on everything,” said Jones.
The report says the genomic medicine service will at first focus mainly on cancers and rare diseases where there are clear benefits. But more tests are in the pipeline to spot patients who may have bad reactions to certain drugs, and potentially to reveal the risk of severe early onset diseases such as Parkinson’s, multiple sclerosis and dementia. Research is ongoing into genetic tests that can be combined with other medical information to highlight patients most at risk of diseases such as breast cancer, diabetes and hypertension.
The report says concerns were raised by the House of Commons science and technology committee over training, expertise and IT infrastructure, and warning of teething problems. That is to be expected, said Newman. “When you set out an ambition it doesn’t mean everything will be in place from day one, but it gives a clear steer on the direction of travel. It’s good to be set a challenge that will put you at the forefront of medicine.”
[link url="https://www.theguardian.com/science/2018/jul/03/nhs-routine-dna-tests-precision-cancer-tumour-screening"]The Guardian report[/link]