RESUMO
BACKGROUND: Fast-growing melanomas are thought to be responsible for the stable incidence of thick melanomas. It has been suggested that campaigns for early diagnosis are unlikely to have a major impact on prognosis as rapid vertical growth rather than diagnostic delay is the major determinant for thick melanomas. OBJECTIVE: We investigated the impact of follow-up examinations on the incidence of thick second primary melanomas (SPMs) and analysed their clinic-pathologic characteristics. METHODS: We analysed a single-centre cohort of 2253 patients of the German Central Malignant Melanoma Registry with prospectively documented follow-up examinations. RESULTS: Primary tumour and patient characteristics were well balanced between patients with and without SPMs except for age (median 61 years, interquartile range [IQR] 51-67 vs. 56 years, IQR 43-67; P = 0.005). Metachronous SPMs occurred in 107 patients (4.7% of total) were thinner than the respective first primary melanoma (FPM) (median Breslow thickness of invasive melanomas 0.40 mm, IQR 0.28-0.75 vs. 0.80 mm, IQR 0.50-2.00; P < 0.001) and less often ulcerated (0.9% vs. 15.0%; P < 0.001). Melanomas >2.00 mm occurred in 2.8% of SPMs as compared to 23.4% of FPMs (P < 0.001). Thick SPMs (>1.00 mm; 14.0%) despite close-meshed follow-up examinations were frequently associated with atypical clinical presentation and uncommon histopathologic subtypes. One-third (5/15) of thick SPMs were clinically misdiagnosed as non-melanocytic lesions, most of them as basal cell carcinomas (n = 4). CONCLUSIONS: Regular total body skin examinations enable a highly efficient detection of early-stage melanomas and reduction of thick melanomas as compared to first primary melanomas. Our data indicate that fast-growing melanomas without opportunity of early detection are rare and cannot explain the stable incidence of thick melanomas. This highlights the importance of close-meshed total body skin examinations in patient groups that are at high risk of first or multiple primary melanomas.
