ASO Visual Abstract: Prognostic Value of Nevus-Associated Melanoma in Patients with Melanoma

Background. Although most melanomas develop de novo, about 30% are nevus-associated melanomas, where the prognostic value is unclear. Our study aimed to determine whether nevus-associated melanoma is associated with sentinel lymph node (SLN) status and prognosis in patients with melanoma. Methods. The Sentinel Lymph Node Working Group database, which includes comprehensive clinicopathological and outcome data, was utilized to investigate the association of nevus-associated melanoma with SLN status as well as relapse-free (RFS), melanoma-specific (MSS), and overall survival (OS) using multivariable logistic regression and Cox regression modeling. Results. A total of 3447 adult patients with a median follow-up of 2.6 years (interquartile range 0.9-6.9) were evaluable. Compared with de novo melanomas, nevus-associated melanomas showed a significant correlation with younger age as well as favorable histological features. The presence of a nevus-associated melanoma was not identified as an independent factor for SLN status (odds ratio 1.06, 95% confidence interval [CI] 0.80-1.41; p = 0.68). Compared with de novo melanomas, nevus-associated melanomas provided independent prognostic information for a favorable RFS (hazard ratio [HR] 0.67, 95% CI 0.53-0.84; p < 0.001), MSS (HR 0.54, 95% CI 0.34-0.85; p = 0.008), and OS (HR 0.42, 95% CI 0.30-0.57; p < 0.001). Conclusion. Melanomas associated with pre-existing nevi appear to be an independent favorable prognostic factor for recurrence and survival and may potentially be used as a clinical parameter for identifying patients with lower risk of recurrence.