New genetic cancer test for children slashes wait time to just days

Children with suspected cancer could be spared unnecessary medical interventions and treatment thanks to a rapid test that identifies genetic tumour changes in a matter of days, a study has found.

Turnaround times for whole genome sequencing (WGS) on the NHS are currently "really long", experts said, with young patients forced to wait between four and six weeks for their results.

Researchers discovered that the quicker analysis helped people avoid invasive surgery, while others were diagnosed with benign conditions that cleared up independently.

A nationwide trial has now been launched to evaluate whether these outcomes can be delivered across the wider health service.

The WGS technique involves taking a tumour sample from a patient and comparing it against skin or saliva samples to identify cellular differences.

This enables clinicians to determine why cancer has developed, identify the specific disease type and its trajectory, and select the most targeted treatments.

The NHS first commissioned WGS for children suspected of cancer in England in 2021.

However, Dr Aditi Vedi, paediatric oncologist at Cambridge University Hospitals and assistant research professor in the department of paediatrics, told the Press Association that turnaroud times are “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.”

The study, published in Nature Communications and supported by biotechnology company Illumina, included samples from 54 children at Addenbrooke’s Hospital with various types of cancer.

Of the total, 35 samples were analysed at the time of diagnosis, and around half of patients had their treatment improved.

Two children avoided invasive treatment for benign tumours, two were able to have less extensive surgery, and one had precision medicine that targeted a specific gene.

Dr Vedi 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.”

One nine-year-old who took part in the study was admitted to Addenbrooke’s Hospital with a collapsed lung, with scans showing a potentially cancerous mass.

Medics suspected lymphoma, with diagnosis usually requiring a tissue sample.

However, the patient was too unwell, so a sample of fluid was taken from his chest.

WGS using this fluid detected a rare condition called T-cell lymphoblastic lymphoma (T-LBL), allowing doctors to treat him more quickly.

NHS England has backed a national trial that will include 200 children over the next two years.

Researchers are developing a national paediatric genomic network of excellence, which will bring together experts to develop rapid WGS for use on the health service.

The national trial will examine if the rapid test is “just as accurate, deliverable, feasible and has a health economic benefit”, Dr Vedi told PA.

She added: “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.”

The network of excellence also has a “future benefit”, Dr Vedi said.

It will allow doctors to analyse data to pinpoint similar traits between conditions, or help understand gene mutations which may mean a patient responds to a chemotherapy drug differently.

“We’re going to develop a database which we can then mine for future research,” Dr Vedi told PA.

“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.”