UK scientists create new skin cancer test that could dramatically boost patient's lives

UK scientists have developed the world's first skin cancer DNA blood test so doctors can hone their patients' treatment for their melanoma. Currently, patients with advanced melanoma carrying a BRAF mutation - the most serious form of skin cancer - are treated with targeted therapy or immunotherapy.

But medics have the challenge of picking the best sequence and timing of their treatments, so if a quick and simple blood test could reveal how a cancer sufferer is responding could make a life or death difference. That's when the pioneering CAcTUS clinical trial in Manchester developed their test to look for tiny fragments of tumour DNA shed by cancer cells and circulating in the bloodstream, called circulating tumour DNA or ctDNA.

They found that ctDNA levels fell rapidly in patients responding to treatment so can provide an indication of success, or in the opposite way resistance, weeks before conventional scans and so saving crucial time.

For example, if a patient began with a short course of targeted therapy to quickly shrink their tumours - they could switch to immunotherapy once the DNA blood test shows ctDNA levels showed a major response.

The results of the CAcTUS clinical trial, published in the medical journal Nature Communications, proves ctDNA testing can be delivered quickly on the NHS to guide future treatment decisions for patients with advanced melanoma carrying the BRAF mutation.

Professor Paul Lorigan, chief investigator for the CAcTUS clinical trial and Professor of medical oncology at The University of Manchester, said: "This study shows that we can use a simple blood test to monitor melanoma in real time and potentially adapt treatment much earlier than has previously been possible.

"For patients with advanced melanoma, particularly those with rapidly progressing disease, having this information quickly is incredibly important.

"I hope in the future analysing the tiny pieces of DNA coming from the cancer found in the patient’s bloodstream could be commonly used to tell when a patient is responding to treatment, and when the best time to change to a new therapy."

The study was led by researchers at the Cancer Research UK National Biomarker Centre and The Manchester Cancer Research Centre and funded by The Christie Charity and Cancer Research UK.

The CAcTUS trial involved using two types of treatment in sequence to attack the melanoma in two different ways. One is targeted therapy, which interferes with how cancer cells grow and survive.

The other is immunotherapy, which helps the immune system ‘see’ the melanoma and attack it.

Dr Rebecca Lee, consultant oncologist and clinician scientist at The Christie and The University of Manchester, who helped develop the trial, said: "This blood test has proved to be accurate, reliable, and sensitive.

"What is particularly exciting is that ctDNA changes can tell us whether treatment is working before we could see it on scans.

"This opens the possibility of making faster, more personalised treatment decisions for patients in the future."

She added: "We now know we can use this blood test in patients as a tool to guide treatment, which will be important in developing personalised treatments in the future.

"This study also highlights the growing role of blood tests in cancer care, where blood samples can provide ongoing insights into tumour behaviour without invasive tissue biopsies."

The trial recruited 21 patients between 2019 and 2022 and focused on patients with a poorer prognosis who had advanced melanoma that could not be removed with surgery.

Patients participated in the research at the National Institute for Health and Care Research (NIHR) Manchester Clinical Research Facility (CRF) at The Christie.

Professor Caroline Dive, Director of the CRUK National Biomarker Centre in Manchester where the blood test was developed and validated, said: "We’re so delighted.

"Results from the blood testing we performed in our laboratories have been shown to be effective in helping our clinical colleagues make informed decisions for patients with melanoma."