Sensitivity and prognostic significance of circulating tumor DNA (ctDNA) in stage I to III malignant melanoma

Abstract Background Risk stratification to guide adjuvant treatment in early stages of melanoma becomes increasingly important. This study investigated circulating tumor (ct)DNA in early melanoma stages to predict disease progression in real-world settings in German melanoma patients. Methods In this retrospective, single-center study, 61 patients with melanoma stages I-III with known disease-progression following primary diagnosis were included. Patients were requested to have baseline serum samples ≤ 4 weeks after diagnosis and ≥ 12 weeks preceding disease progression. In ctDNA isolated from 185 serum samples matching inclusion criteria, BRAF V600E/K, NRAS Q61K/L/R and TERT promoter mutations were quantified and correlated with serum levels of S100 and LDH. Results Mutated ctDNA was detected in ≥ 1sample in 43 of 53 patients (81.13%). CtDNA was more sensitive in the prediction of melanoma relapse than established biomarker S100, LDH ( p < 0.001) and both LDH/S100 ( p < 0.001). Highest mean ctDNA was measured during shift of stage III to stage IV disease (24.25 cps/µL) and shift within stage III (12.42 cps/µL). The detection of ctDNA at any time point trended towards shorter overall survival. Conclusion Our study demonstrates the superiority of ctDNA harboring melanoma specific mutations over LDH and S100 in identifying patients at risk for recurrence in early melanoma stages in a single center cohort of melanoma patients. Future prospective trials are warranted to confirm this.