Blood-Based MRD Test Predicts Recurrence Risk After Melanoma Surgery

After surgery, recurrence prediction remains difficult at the individual-patient level, and conventional clinicopathologic staging provides only a static estimate of risk. A newly evaluated tissue-free liquid biopsy approach now supports blood-based molecular residual disease detection and recurrence monitoring in resected melanoma.

Guardant Health’s Guardant Reveal is a tissue-free liquid biopsy test for molecular residual disease (MRD) detection and recurrence monitoring. The assay detects circulating tumor DNA (ctDNA) using an epigenomic approach and does not require tumor tissue. Results from COSMOS-MEL01, part of the COSMOS (COnquer Solid Malignancies by blOod Screening) program, were published in Cancer Research Communications, a journal of the American Association for Cancer Research.

COSMOS-MEL01 was the first published prospective, multicenter evaluation of Guardant Reveal in patients with resected stage II–III melanoma. The study analyzed 280 longitudinal surveillance samples from 48 patients with clinical stage II–III melanoma treated with surgery. Detection of ctDNA after surgery was strongly associated with recurrence and melanoma-related death.

During longitudinal surveillance, Guardant Reveal detected 81% of distant recurrences and showed 100% specificity in post-treatment samples from patients who remained recurrence-free. ctDNA detection preceded clinical identification of recurrence by a median of 70.5 days, with a reported lead time of up to 273 days. MRD detection approximately four weeks after surgery was independently associated with an approximately 12-fold increased risk of recurrence and a greater than 30-fold increased risk of death.

The findings support the use of Guardant Reveal as a rapid, noninvasive approach for earlier identification of patients at high risk for recurrence. The test is also described for MRD detection and recurrence monitoring in early-stage colorectal, breast, and lung cancers. It can also be used for late-stage therapy response monitoring in patients with solid tumors.

“Patients with resected, high-risk melanoma need more precise tools to assess how their risk changes after surgery and throughout surveillance. These results show that ctDNA detection using a tissue-free assay was associated with a substantially increased risk of recurrence and melanoma-related death and often preceded clinical detection of disease. Fast, broadly accessible testing would be valuable in helping to inform therapy for patients with substantially higher risk of melanoma recurrence and poorer survival than those who remained ctDNA-negative,” said Yoshiaki Nakamura, M.D., Ph.D., former Chief, International Research Promotion Office at National Cancer Center Hospital East in Chiba, Japan, and a co-lead author of the study.

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