Non-pigmented melanoma: a clinical case and difficulties in diagnosis

bp), coefficient of variation (CV%), and the ratio of 20-150 bp/160-180 bp fragments.Statistical analyses comprised non-parametric tests for descriptive comparisons and Cox mixed-effects (CoxME) models for survival analysis. Example fragmentation pattern showing the regions studiedResults: cfDNA concentration significantly differs across clinical stages from 0.84 ng/ml (controls) to 1.20ng/ml (unresectable disease, p<0.01).The ranges of 20-150 and 250-320 bp showed significant differences in terms of proportion, average size and CV% across all clinical stages (all p<0.01).The ranges of 160-180 and 180-220 bp showed significant differences in proportion and CV% (p=0.03).In a multivariate CoxME model adjusting for clinical covariates, the ratio 20-150 bp/160-180 bp emerged as an independent predictor of melanoma relapse (HR: 13.11, 95% CI: 1.94-88.73,p<0.01).Conclusions: Distinct cfDNA fragmentation patterns characterize melanoma patients with and without active disease.cfDNA fragmentomics represents a promising biomarker for detecting melanoma relapse and assessing relapse risk, with potential clinical applications in personalized patient monitoring.