Synchronous primary cutaneous melanomas: a descriptive study of their clinical features, histology, genetic background of the patients and clinical outcomes.

BACKGROUND: Around 0.5% of cutaneous melanoma (CM) patients will present with synchronous melanomas when first seen. Moreover, 26-40% of patients with multiple primary melanomas present with synchronous lesions. OBJECTIVES: To assess the prevalence, clinical and histopathological characteristics, germline mutations and outcome in patients with synchronous melanoma. METHODS: Clinical and histopathological data from 4703 melanoma patients were included. Clinical, histological and genetic mutational status information was analysed. Kaplan-Meier curves were used to investigate survival outcomes. RESULTS: A total of 144 patients (3.06%) presented simultaneously with two or more primary melanomas. During follow-up, 25.7% of patients with synchronous melanoma developed a new primary melanoma compared to 8.6% of patients diagnosed with single melanoma (P < 0.001). Germinal CDKN2A mutations were identified in 10.7% of patients with synchronous melanomas and genetic variants in MC1R in 72%. No significant differences in all survival outcomes between patients with synchronous melanomas and single melanomas were found. CONCLUSION: Synchronous melanomas are more frequent than previously reported and are more frequent in older patients compared to single melanomas. Moreover, these patients have a higher risk of developing a new primary melanoma during follow-up and have higher rates of germline susceptibility variants. Nevertheless, these findings were not associated with worse outcomes.

Inherited MC1R variants in patients with melanoma are associated with better survival in women.

BACKGROUND: Women have a better melanoma prognosis, and fairer skin/hair colour. The presence of inherited MC1R variants has been associated with a better melanoma prognosis, but its interaction with sex is unknown. OBJECTIVES: To evaluate the relationship between germline MC1R status and survival, and determine any association with sex. METHODS: This was a cohort study including 1341 patients with melanoma from the Melanoma Unit of the Hospital Clinic of Barcelona, between January 1996 and April 2018. We examined known sex-related prognosis factors as they relate to features of melanoma and evaluated the sex-specific role of MC1R in overall and melanoma-specific survival. Hazard ratios (HRs) were calculated using univariate and multivariate Cox logistic regression. RESULTS: Men showed lower overall survival than women (P < 0·001) and the presence of inherited MC1R variants was not associated with better survival in our cohort. However, in women the presence of MC1R variants was associated with better overall survival in the multivariate analysis [HR 0·57, 95% confidence interval (CI) 0·38-0·85; P = 0·006] but not in men [HR 1·26, 95% CI 0·89-1·79; P = 0·185 (P-value for interaction 0·004)]. Analysis performed for melanoma-specific survival showed the same level of significance. CONCLUSIONS: Inherited MC1R variants are associated with improved overall survival in women with melanoma but not in men. Intrinsic sex-dependent features can modify the role of specific genes in melanoma prognosis. We believe that survival studies of patients with melanoma should include analysis by sex and MC1R genotype. What's already known about this topic? Inherited MC1R variants have been associated with a better melanoma prognosis, but their interaction with sex is unknown. What does this study add? MC1R variants are related to better overall survival and melanoma-specific survival in women but not in men. What is the translational message? These differences between the sexes could imply future changes in melanoma follow-up and treatment strategies. This provides a basis for understanding the interaction between sex-related genes and germline variants in cancer.

Detection of cell-free circulating BRAFV 600E by droplet digital polymerase chain reaction in patients with and without melanoma under dermatological surveillance.

BACKGROUND: The p.V600E mutation in the BRAF protein is the most frequent mutation in cutaneous melanoma and is a recurrent alteration found in common benign naevi. Analysis of the cell-free BRAF c.1799T>A, p.V600E mutation (cfBRAFV 600E ) in plasma has emerged as a biomarker for monitoring prognosis and treatment response in patients with melanoma. OBJECTIVES: To quantify cfBRAFV 600E levels in plasma from patients with melanoma and from patients without melanoma undergoing regular follow-up of their melanocytic lesions, in order to assess the clinical significance of the test. METHODS: We quantified cfBRAFV 600E by droplet digital polymerase chain reaction in plasma from 146 patients without melanoma undergoing continuous dermatological screening, from 26 stage III and seven stage IV patients with BRAF-mutant melanoma, and from 32 patients with melanoma who were free of disease for 3 or more years. RESULTS: Among disease-free patients and individuals without melanoma, 52% presented a high naevus count (> 50) and 49% had clinically atypical naevi. cfBRAFV 600E was detected in 71% of patients with stage IV melanoma and 15% with stage III, and in 1·4% of individuals without melanoma. No cfBRAFV 600E mutation was detected in disease-free patients with melanoma. Individuals without melanoma had lower cfBRAFV 600E levels than patients with melanoma. We established a variant allelic frequency of 0·26% or 5 copies mL-1 of cfBRAFV 600E as the optimal cutoff value for identifying patients with melanoma with > 99% specificity. CONCLUSIONS: This study suggests that naevus-related factors do not influence the detection of cfBRAFV 600E in individuals without melanoma, and supports the clinical diagnostic value of plasma cfBRAFV 600E quantification in patients with melanoma. What's already known about this topic? The analysis of the BRAF c.1799T>A (p.V600E) mutation in cell-free (cf)DNA has emerged as a potential biomarker for monitoring prognosis and treatment response in patients with metastatic BRAFV600E melanoma. The BRAFV600E alteration is a common genetic alteration found in benign proliferations such as melanocytic naevi. No information exists about the impact of the number of common acquired naevi or the presence of clinically atypical naevi in cfBRAFV600E detection in an individual. What does this study add? The cfBRAFV600E mutation is detected in plasma from a reduced number of individuals without melanoma undergoing continuous dermatological follow-up. A high number of naevi or the presence of clinically atypical naevi are factors that do not influence cfBRAFV600E detection in an individual. Both total cfBRAF concentration and cfBRAFV600E frequency are effective biomarkers in patients with advanced melanoma but not in patients at early stages or with micrometastases. What is the translational message? Detection of cfBRAFV600E in an individual is not influenced by naevus-related factors. cfBRAFV600E is a robust and reliable biomarker that can be used in dermatological surveillance programmes.

KIT mutations and CD117 overexpression are markers of better progression-free survival in vulvar melanomas.

BACKGROUND: Few studies have addressed prognostic markers and none has correlated molecular status and prognosis in vulvar melanomas. OBJECTIVES: To evaluate the clinicopathological features of 95 cases of vulvar melanoma. METHODS: p53, CD117, Ki-67, neurofibromin, brafv600e and nrasq61r immunostains, and molecular analyses by either targeted next-generation or direct sequencing, were performed on available archival materials. RESULTS: Molecular testing detected mutations in KIT (44%), BRAF (25%), NF1 (22%), TP53 (17%), NRAS (9%) and TERT promoter (9%). Co-mutation of KIT and NF1 and of KIT and NRAS were identified in two and one cases, respectively. KIT mutations were significantly associated with better progression-free survival in univariate analyses. In multivariate analyses CD117 expression was significantly associated with better progression-free survival. Tumour thickness was significantly associated with worse progression-free and overall survival, and perineural invasion significantly correlated with reduced melanoma-specific survival and reduced overall survival. Cases were from multiple centres and only a subset of samples was available for molecular testing. CONCLUSIONS: KIT mutations and CD117 overexpression are markers of better progression-free survival. In addition to its prognostic value, molecular testing may identify cases that might respond to targeted agents or immunotherapeutic approaches.

Mutational status of naevus-associated melanomas.

BACKGROUND: The origin of melanoma has always been a debated subject, as well as the role of adjacent melanocytic naevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a naevus. OBJECTIVES: To evaluate the presence of mutations in genes from well-known melanomagenesis pathways in a large series of naevus-associated melanomas. MATERIALS AND METHODS: Sixty-one melanomas found in association with a pre-existing naevus were microdissected, after careful selection of cell subpopulations, and submitted to Sanger sequencing of the BRAF, NRAS, c-KIT, PPP6C, STK19 and RAC1 genes. Each gene was evaluated twice in all samples by sequencing or by sequencing and another confirmation method, allele-specific fluorescent polymerase chain reaction (PCR) and capillary electrophoresis detection or by SNaPshot analysis. Only mutations confirmed via two different molecular methods or twice by sequencing were considered positive. RESULTS: The majority of cases presented concordance of mutational status between melanoma and the associated naevus for all six genes (40 of 60; 66.7%). Nine cases presented concomitant BRAF and NRAS mutations, including one case in which both the melanoma and the adjacent naevus harboured V600E and Q61K double mutations. In two cases, both melanoma and associated naevus located on acral sites were BRAF mutated, including an acral lentiginous melanoma. CONCLUSIONS: To our knowledge this is the largest naevus-associated melanoma series evaluated molecularly. The majority of melanomas and adjacent naevi in our sample share the same mutational profile, corroborating the theory that the adjacent naevus and melanoma are clonally related and that the melanoma originated within a naevus.