The dynamics of circulating tumour DNA (ctDNA) during treatment reflects tumour response in advanced melanoma patients.

Despite the introduction of targeted (BRAFi/MEKi) and immune checkpoint inhibitors (ICIs) has significantly reduced the recurrence rate and improved the overall survival (OS) of patients with Stage III and IV melanoma, only a percentage will benefit of durable disease control. The aim of this study was to examine whether the levels of circulating tumour DNA (ctDNA) in plasma of advanced melanoma patients undergoing BRAFi/MEKi or ICIs vary according to the patients' survival outcomes (i.e. progression-free survival (PFS) and OS) and disease progression. Plasma samples of Stage III-IV melanoma patients were collected at baseline (treatment initiation) and thereafter every 3 months. Circulating BRAFV600E/K and NRASQ61R/K mutations were analysed through droplet digital PCR (ddPCR, Bio-Rad) in a total of 177 plasma samples from 48 melanoma patients (19 Stage III, 29 Stage IV). Baseline ctDNA concentration was significantly associated with OS (HR = 1.003, 95% CI = 1.000-1.006, p = 0.043) and PFS (HR = 1.004, 95% CI = 1.000-1.007, p = 0.029) independent of clinical-prognostic confounders. For each unit increase in the ∆ctDNA (concentration difference between the last follow-up and baseline) there was a 24% increased risk of disease progression, irrespective of treatment type and stage at diagnosis (OR = 1.24, 95% CI = 1.03-1.49, p = 0.020, AUC = 0.93). Patients with reduction of ctDNA level from baseline to the last follow-up had longer OS (HR = 0.14; 95% CI = 0.05-0.44, p = 0.001) and PFS (HR = 0.08; 95% CI = 0.03-0.27, p < 0.0001) compared to patients with increased ctDNA, including adjustment for confounding factors. Our findings suggest that variation of ctDNA over time during melanoma treatment reflects the clinical outcome and tumour response to therapy and might be helpful in clinical monitoring.

Melanocytic Lesions with Peripheral Globules: Proposal of an Integrated Management Algorithm.

INTRODUCTION: A peripheral rim of globules represents a marker of the horizontal growth phase in nevi and is a common feature in children and adolescents. The observation of melanocytic lesions with peripheral globules (MLPGs) in adulthood deserves more attention, since melanoma may exhibit this feature, albeit rarely. Risk-stratified management recommendations considering a global clinical approach are still missing. OBJECTIVES: To analyze current knowledge on MLPGs and propose an integrated management algorithm stratified for age groups. METHODS: We conducted a narrative review of current published data on MLPGs, analyzing clinical dermoscopic and confocal distinguishing features of melanoma from benign nevi. RESULTS: The risk of finding a melanoma when removing an MLPG increases with age, especially in people >55 years old, and is significantly higher in the extremities, head/neck and in case of a single asymmetrical lesion, ≥6 mm in diameter. Dermoscopic features associated with melanoma diagnosis include atypical peripheral globules, asymmetrical distribution, multiple rims as well as the reappearance of globules after prior loss. In addition, wide blue-grey regression areas, atypical networks, eccentric blotches, tan structureless peripheral areas and vascularization are atypical dermoscopic features. Confocal worrisome findings are represented by pagetoid cells within the epidermis, architectural disarrangement and atypical cells of the dermo-epidermal junction with irregular peripheral nests. CONCLUSION: We proposed a multi-step age-stratified management algorithm integrating clinical, dermoscopic and confocal findings that may increase the early recognition of melanoma and avoid surgical excision of benign nevi.