Majority of melanomas occur de novo

September 12, 2017

Abstract

The reported prevalence of nevus-associated melanoma varies substantially. We performed a systematic review and meta-analysis to determine the incidence and prevalence of this disease; we also performed subanalyses considering age, tumor thickness, and nevus-type classification. In 38 observational cohort and case–control studies, 29.1% of melanomas likely arose from a preexisting nevus and 70.9% de novo. Any given melanoma was 64% less likely to be nevus-associated than de novo (risk ratio 0.36, 95% confidence interval [CI] 0.29-0.44; P < .001; I2 = 99%); nevus-associated melanomas had a lower mean Breslow thickness than de novo melanomas (mean difference –0.39 mm; 95% CI –0.60 to –0.18; P = .0003; I2 = 66%). No significant differences were noted regarding the association of nevus-associated melanomas with nondysplastic nevi or dysplastic nevi (risk ratio 0.77, 95% CI 0.49-1.20; P = .24; I2 = 98%).

Source:

Pampena, R, et al. A meta-analysis of nevus-associated melanoma: Prevalence and practical implications.  JAAD. Article in Press. Published online 29 August 2017.  http://www.jaad.org/article/S0190-9622(17)32051-0/fulltext