Circulating Tumour DNA guidEd Therapy for Stage IIB/C mElanoma After surgiCal resecTION

The trial is looking for new and better ways to treat melanoma, an aggressive type of skin cancer. Having surgery to remove the melanoma will cure the majority of patients with early stage disease. However, a small percentage of these patients will go on to develop further disease, which may spread to other places in their body. Currently, patients who have been cured of melanoma will have appointments in clinic to check that further disease has not developed or returned and some may also receive regular scans. The trial team has developed a blood test that tells us whether cancer cells are still present or is becoming active after a patient has been 'cured' of melanoma, even if a scan looks normal. The test looks for pieces of DNA in the blood that are known to have come from the cancer, which we call 'circulating tumour DNA', or ctDNA. Patients who have ctDNA in their blood have an extremely high chance of the cancer returning. By using the blood test that we have developed we think that we can identify patients earlier than normal. We think that some of the treatments that are used when melanoma cancer has spread may benefit patients at this earlier stage. We want to see if these patients with ctDNA in their blood, who have a higher risk of their cancer returning or spreading, and receive treatment early have a better response to their cancer compared to those patients who receive treatment when their cancer has returned and it can be seen on a scan. This could mean we would be able to offer patients earlier treatment in the future using just a blood test rather than a scan, while also providing reassurance to those patients that do not have ctDNA in their blood that they do not need treatment and their cancer is not returning.