BACKGROUND: Melanoma is the most aggressive skin cancer with ability to recur also after early-stage tumor surgery. The aim was to identify early-stage melanoma patients at high risk of recurrence using liquid biopsy, estimating of mutated BRAF ctDNA and the level of tumor marker S100B in plasma. METHODS: Eighty patients were enrolled in the study. BRAF V600E mutation was determined in FFPE tissue and plasma samples using ultrasensitive ddPCR with pre-amplification. The level of S100B was determined in plasma by immunoassay chemiluminescent method. RESULTS: The best prediction of melanoma recurrence after surgery was observed in patients with combined high level of S100B (S100Bhigh) and ctDNA BRAFV600E (BRAFmut) in preoperative (57.1% vs. 12.5%, p = 0.025) as well as postoperative blood samples (83.3% vs. 14.3%, resp., p = 0.001) in comparison with low S100B and BRAF wild-type. Similarly, patients with preoperative and postoperative S100Bhigh and BRAFmut experienced worse prognosis (DFI p = 0.05, OS p = 0.131 and DFI p = 0.001, OS = 0.001, resp.). CONCLUSION: We observed the benefit of the estimation of combination of S100B and ctDNA BRAFmut in peripheral blood for identification of patients at high risk of recurrence and unfavorable prognosis. SIGNIFICANCE: There is still no general consensus on molecular markers for deciding the appropriateness of adjuvant treatment of early-stage melanoma. We have shown for the first time that the combined determination of the ctDNA BRAFmut oncogene (liquid biopsy) and the high level of tumor marker S100B in pre- and postoperative plasma samples can identify patients with the worst prognosis and the highest risk of tumor recurrence. Therefore, modern adjuvant therapy would be appropriate for these patients with resectable melanoma, regardless of disease stage.

• Klíčová slova
• BRAF V600E, S100B, ctDNA, ddPCR, melanoma,
• MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokální recidiva nádoru * genetika   krev   MeSH
• melanom * genetika   krev   patologie   diagnóza   chirurgie   MeSH
• mutace * MeSH
• nádorové biomarkery * krev   genetika   MeSH
• nádory kůže * krev   genetika   patologie   diagnóza   chirurgie   MeSH
• prediktivní hodnota testů MeSH
• prognóza MeSH
• protoonkogenní proteiny B-Raf * genetika   krev   MeSH
• S-100 kalcium vázající protein G, podjednotka beta * krev   genetika   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• staging nádorů MeSH
• tekutá biopsie metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BRAF protein, human MeSH Prohlížeč
• nádorové biomarkery * MeSH
• protoonkogenní proteiny B-Raf * MeSH
• S-100 kalcium vázající protein G, podjednotka beta * MeSH
• S100B protein, human MeSH Prohlížeč

BACKGROUND: Implementation of adjuvant therapies in non-metastatic melanoma improved treatment outcomes in some patients; however, adjuvant therapy can be associated with significant cost and risk of toxicity. Therefore, there is an unmet need to better identify patients at high risk of recurrence. PATIENTS AND METHODS: We carried out an ultrasensitive droplet digital PCR (ddPCR)-based detection of BRAFV600E-mutated circulating tumor DNA (ctDNA) from blood samples prospectively collected before surgery, 1 hour after surgery, and then serially during follow-up. RESULTS: In 80 patients (stages ≤III), BRAFV600E mutations were detected in 47.2% of tissue, in 37.7% of ctDNA samples collected before surgery, and in 25.9% of ctDNA samples collected 1 hour after surgery. Patients with detected ctDNA in blood collected 1 hour after surgery compared to patients without detected ctDNA had higher likelihood of melanoma recurrence (P < 0.001) and shorter median disease-free survival (P = 0.001) and overall survival (P = 0.003). CONCLUSIONS: Ultrasensitive ddPCR can detect ctDNA in pre- and post-surgical blood samples from patients with resectable melanoma. Detection of ctDNA in post-surgical samples is associated with inferior treatment outcomes.

• Klíčová slova
• circulating tumor DNA, liquid biopsy, melanoma,
• MeSH
• cirkulující nádorová DNA * genetika   MeSH
• lidé MeSH
• melanom * genetika   MeSH
• mutace * MeSH
• polymerázová řetězová reakce MeSH
• protoonkogenní proteiny B-Raf * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• BRAF protein, human MeSH Prohlížeč
• cirkulující nádorová DNA * MeSH
• protoonkogenní proteiny B-Raf * MeSH