A rapid DNA test that returns results in days could spare children with suspected cancer from unnecessary tests and treatment, a study has found.
The new test looks for genetic changes in tumours, but can return results in just two to three days, much faster than the “really long” wait times currently faced, according to experts. Youngsters undergoing whole genome sequencing (WGS) on the NHS are currently facing wait times of around four to six weeks, meaning doctors may have to make crucial treatment decisions before results come back.
Faster results change care for children
Researchers found the faster test made a significant difference to children, with some avoiding invasive treatment, including surgery, altogether, while others were diagnosed with a benign condition that resolved on its own.
A study of samples from 54 children found two youngsters with benign tumours were spared treatment, while another two underwent less extensive surgery. A fifth child was given precision medicine targeting a specific gene.
The study involved samples from 54 children treated at Addenbrooke’s Hospital in Cambridge with different types of cancer. Of those, 35 were analysed at the time of diagnosis or relapse, with the rapid results improving the care of around half.
Case study: nine-year-old with collapsed lung
One nine-year-old involved in the study was rushed to hospital with a collapsed lung after scans revealed a mass feared to be cancerous. Doctors suspected lymphoma, but the youngster was too unwell to undergo the procedure normally needed to take a tissue sample.
Instead, medics used fluid from the child’s chest for rapid WGS. It detected a rare cancer called T-cell lymphoblastic lymphoma (T-LBL), allowing doctors to begin treatment more quickly.
Dr Aditi Vedi, a paediatric oncologist at Cambridge University Hospitals, said the current wait for WGS results was “really long”.
She said: “It takes about four to six weeks in reality for the results to come back, and as you can imagine, for childhood cancer we can’t really wait four to six weeks to make treatment decisions. We often have to rely on multiple other tests to come to the same conclusion. Our study showed that we can return that same data just as accurate within two to three days, which means that we can actually make a meaningful difference to these patients.”
National trial backed by NHS England
WGS works by comparing genetic information from a patient’s tumour with a sample of their skin or saliva to identify differences. It can help doctors establish what type of cancer a child has, how it could behave and which treatment is most likely to work.
Dr Vedi said the children who were able to avoid or scale back treatment were particularly important because it could also spare them potentially long-term side effects.
She said: “The most important category for me was the group of patients that didn’t have any treatment, or avoided treatment, or downscaled the treatment that they got as a result of getting their whole genome sequencing back faster. There’s a handful of patients who either avoided treatment altogether, got less treatment, got more targeted therapy, and I think that’s the group that we want to try and identify early, so that we can not just avoid treatment, but avoid all the side-effects of having treatment, not just now, but long term as well for these patients.”
WGS has been available for children with suspected cancer in England since 2021. NHS England has now backed a national trial involving 200 children over the next two years to see whether the rapid approach can work on a wider scale. Researchers hope it could eventually mean children across England get faster results regardless of where they live.
Dr Vedi said: “We’re keen not to have a postcode lottery and have children outside of Cambridgeshire access this technology as well. NHS England have given us some funding to broaden this on a national scale, so that children across the country can access this rapid sequencing as well. If we can show that there’s a health economic benefit, the aim is that NHS England will then commission this for children across the country and make it more widely available.”
Researchers are also developing a national paediatric genomic network which could help doctors spot similarities between conditions and understand why some children respond differently to chemotherapy. The genomic information could eventually form a database used to help future patients.
Dr Vedi said: “The patients who are participating in this network of excellence will not only benefit from the network themselves, but will also benefit future patients through creating this library.”
