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

Abstract

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.