UK scientists have developed the world's first skin cancer DNA blood test, allowing doctors to personalize treatment for patients with advanced melanoma. The breakthrough could significantly improve patient outcomes by enabling real-time monitoring of how well therapy is working.
How the Test Works
Currently, patients with advanced melanoma carrying a BRAF mutation are treated with targeted therapy or immunotherapy. However, doctors face challenges in choosing the best sequence and timing of treatments. The pioneering CAcTUS clinical trial in Manchester created a test that detects circulating tumour DNA (ctDNA) – tiny fragments of tumour DNA shed by cancer cells into the bloodstream.
The study found that ctDNA levels fell rapidly in patients responding to treatment, providing an early indication of success or resistance weeks before conventional scans. This allows doctors to adjust therapy sooner, potentially making a life-or-death difference.
Clinical Trial Results
For example, a patient could begin with a short course of targeted therapy to quickly shrink tumours, then switch to immunotherapy once the blood test shows ctDNA levels indicate a major response. The results, published in Nature Communications, prove that ctDNA testing can be delivered quickly on the NHS to guide treatment decisions for advanced melanoma patients with the BRAF mutation.
Professor Paul Lorigan, chief investigator of the CAcTUS 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 previously possible. For patients with rapidly progressing disease, having this information quickly is incredibly important."
Expert Insights
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."
Trial Details
The CAcTUS trial involved using two types of treatment in sequence: targeted therapy, which interferes with how cancer cells grow and survive, and immunotherapy, which helps the immune system attack the melanoma. The study recruited 21 patients between 2019 and 2022, focusing on those with a poorer prognosis who had advanced melanoma that could not be removed with surgery. Patients participated at the National Institute for Health and Care Research (NIHR) Manchester Clinical Research Facility 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."
The study was led by researchers at the Cancer Research UK National Biomarker Centre and The Manchester Cancer Research Centre, funded by The Christie Charity and Cancer Research UK.
