T-Type Calcium Channels: A Potential Novel Target in Melanoma

T-type calcium channels (TTCCs) are overexpressed in several cancers. In this review, we summarize the recent advances and new insights into TTCC biology, tumor progression, and prognosis biomarker and therapeutic potential in the melanoma field. We describe a novel correlation between the Cav3.1 isoform and the increased basal autophagy in BRAFV600E-mutant melanomas and after acquired resistance to BRAF inhibitors. Indeed, TTCC blockers reduce melanoma cell viability and migration/invasion in vitro and tumor growth in mice xenografts in both BRAF-inhibitor-sensitive and -resistant scenarios. These studies open a new, promising therapeutic approach for disseminated melanoma and improved treatment in BRAFi relapsed melanomas, but further validation and clinical trials are needed for it to become a real therapeutic optionThis work was supported by grants from ISCIII/FEDER “Una manera de hacer Europa” (PI1500711 to RMM; PI18/00573 to RMM and AM). CB and PS hold a pre-doctoral fellowship from UdL-IRBLleida. RI holds a pre-doctoral fellowship from Asociación Española Contra el Cancer (AECC), Catalunya Contra el Cancer, Lleida. AM holds a post-doctoral fellowship from Asociación Española Contra el Cancer (AECC)

BRAFV600E Mutant Allele Frequency (MAF) Influences Melanoma Clinicopathologic Characteristics

Background: Cutaneous melanoma shows high variability regarding clinicopathological presentation, evolution and prognosis. Methods: Next generation sequencing was performed to analyze hotspot mutations in different areas of primary melanomas (MMp) and their paired metastases. Clinicopathological features were evaluated depending on the degree of variation of the BRAFV600E mutant allele frequency (MAF) in MMp. Results: In our cohort of 14 superficial spreading, 10 nodular melanomas and 52 metastases, 17/24 (71%) melanomas had a BRAFV600E mutation and 5/24 (21%) had a NRASQ61 mutation. We observed a high variation of BRAFV600E MAF (H-BRAFV600E) in 7/17 (41%) MMp. The H-BRAFV600E MMp were all located on the trunk, had lower Breslow and mitotic indexes and predominantly, a first nodal metastasis. Regions with spindled tumor cells (Spin) and high lymphocytic infiltrate (HInf) were more frequent in the H-BRAFV600E patients (4/7; 57%), whereas regions with epithelial tumor cells (Epit) and low lymphocytic infiltrate (LInf) were predominant (6/10; 60%) and exclusive in the low BRAFV600E MAF variation tumors (L-BRAFV600E). The H-BRAFV600E/Spin/HInf MMp patients had better prognostic features and nodal first metastasis. Conclusions: The H-BRAFV600E MMp were located on the trunk, had better prognostic characteristics, such as lower Breslow and mitotic indexes as well as high lymphocytic infiltrate.This work was supported by grants from ISCIII and FEDER (“una manera de hacerEuropa”) PI15/00711 to RMM and PI18/00573 to RMM & AM. CIBERONC (CB16/12/00231) to XMG.Postdoctoral AECC (POSTD004MACI - POSTD16) to AM. Predoctoral UdL to PS and predoctoralAECC fellowship to IR. The work was also supported by the Xarxa de Bancs de Tumors de Catalunyasponsored by “Pla Director d’Oncologia de Catalunya (XBTC)”and IRBLleida Biobank (B.0000682)and PLATAFORMA BIOBANCOS (PT17/0015/0027; PT20/00021

Frequency and Clinicopathological Profile Associated with Braf Mutations in Patients with Advanced Melanoma in Spain

Real-world data on BRAF mutation frequency in advanced melanoma are lacking in Spain. Moreover, data available on clinicopathological profile of patients with advanced BRAF-mutant melanoma are currently limited. This study aimed to assess the frequency of BRAF V600 mutations in Spanish patients with advanced or metastatic melanoma and to identify clinical and histopathological features associated with BRAF-mutated tumors. A multicenter, cross-sectional epidemiological study was conducted in 33 Spanish hospitals in adult patients with stage IIIc/IV melanoma. A total of 264 patients were included. The median age was 68 years and 57% were male. Melanoma mainly involved skin with intermittent (40.4%) and low or no sun exposure (43.5%). Most patients (85.6%) had stage IV disease (M1a: 19.3%; M1b: 13.3%; M1c: 22.7%). Serum lactate dehydrogenase levels were elevated in 20% of patients. Superficial spreading melanoma was the most frequent histological type (29.9%). Samples were predominantly obtained from metastases (62.7%), mostly from skin and soft tissues (80%). BRAF mutation analysis was primarily performed using the Cobas 4800 BRAF V600 Mutation Test (92.8%) on formalin-fixed, paraffin-embedded tissue (95.8%). BRAF mutations were detected in 41.3% of samples. Multivariate analysis identified age (odd ratio [OR] 0.975) and stage IV M1a (OR 2.716) as independent factors associated with BRAF mutation. The frequency of BRAF mutations in tumor samples from patients with advanced or metastatic melanoma in Spain was 41.3%. BRAF mutations seem to be more frequent in younger patients and stage M1a patients. This study provides the basis for further investigation regarding BRAF-mutated advanced melanoma in larger cohorts.This study was sponsored by Roche Farma S.A

Epidemiology of Melanocytic Naevi in Children from Lleida, Catalonia, Spain: Protective Role of Sunscreen in the Development of Acquired Moles

The worldwide incidence of malignant melanoma is increasing. The number of pigmented naevi and amount of solar exposure are important risk factors. The aim of this study was to characterize a paediatric population (from Lleida, Catalonia, Spain) in terms of phenotype, sun behaviour and naevi prevalence. Data on the numbers and distributions of acquired naevi in 369 children, aged 4, 8 and 14 years, were collected and correlated with age, sex, skin phototype and environmental factors (annual/lifetime intermittent and chronic sun exposure, sunburns and sunscreen use). The density of naevi increased with age. Boys had more naevi on the trunk and girls had more naevi on the legs. Children with light skin phototype had more naevi. A higher level of accumulated sun exposure correlated with a higher number of naevi in children with non-adequate sunscreen use. In conclusion, several risk factors associated with naevi density and distribution were found, as previously reported by others. Multivariate analysis confirmed a protective role of sunscreen in the development of acquired melanocytic naevi