Mucosal melanomas in the head and neck region are most frequently located in the nasal cavity and paranasal sinuses.,Sinonasal mucosal melanoma (SNMM) comprises <1% of all melanomas.,The aim was to determine the KIT, NRAS and BRAF mutation frequencies in a large series of primary SNMMs.,Laser capture microdissection was used to isolate tumour cells from 56 formalin-fixed paraffin-embedded tumours.,The tumour cells were screened for KIT, NRAS and BRAF mutations by direct sequencing.,Overall, 21% (12 out of 56) of SNMMs harboured KIT, NRAS or BRAF mutations.,Mutations in these oncogenes occurred in a mutually exclusive manner.,Both KIT and BRAF mutations were identified at a similar frequency of 4% each (2 out of 56), whereas NRAS mutations were detected in 14% (8 out of 56) of the SNMMs.,Four of the NRAS mutations were located in exon 1.,Mutations in these oncogenes were significantly more common in melanomas located in the paranasal sinuses than in nasal cavity (P=0.045).,In a multivariate analysis, patients with melanomas in the nasal cavity had a significantly better overall survival than those with tumours in the paranasal sinuses (P=0.027).,Our findings show that KIT and BRAF mutations, which are accessible for present targeted therapies, are only rarely present in SNMMs, whereas NRAS mutations seem to be relatively more frequent.,The data show that majority of SNMMs harbour alterations in genes other than KIT, NRAS and BRAF.
Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4, has demonstrated an improvement in overall survival in two phase III trials of patients with advanced melanoma.,The primary objective of the current trial was to prospectively explore candidate biomarkers from the tumor microenvironment for associations with clinical response to ipilimumab.,In this randomized, double-blind, phase II biomarker study (ClinicalTrials.gov NCT00261365), 82 pretreated or treatment-naïve patients with unresectable stage III/IV melanoma were induced with 3 or 10 mg/kg ipilimumab every 3 weeks for 4 doses; at Week 24, patients could receive maintenance doses every 12 weeks.,Efficacy was evaluated per modified World Health Organization response criteria and safety was assessed continuously.,Candidate biomarkers were evaluated in tumor biopsies collected pretreatment and 24 to 72 hours after the second ipilimumab dose.,Polymorphisms in immune-related genes were also evaluated.,Objective response rate, response patterns, and safety were consistent with previous trials of ipilimumab in melanoma.,No associations between genetic polymorphisms and clinical activity were observed.,Immunohistochemistry and histology on tumor biopsies revealed significant associations between clinical activity and high baseline expression of FoxP3 (p = 0.014) and indoleamine 2,3-dioxygenase (p = 0.012), and between clinical activity and increase in tumor-infiltrating lymphocytes (TILs) between baseline and 3 weeks after start of treatment (p = 0.005).,Microarray analysis of mRNA from tumor samples taken pretreatment and post-treatment demonstrated significant increases in expression of several immune-related genes, and decreases in expression of genes implicated in cancer and melanoma.,Baseline expression of immune-related tumor biomarkers and a post-treatment increase in TILs may be positively associated with ipilimumab clinical activity.,The observed pharmacodynamic changes in gene expression warrant further analysis to determine whether treatment-emergent changes in gene expression may be associated with clinical efficacy.,Further studies are required to determine the predictive value of these and other potential biomarkers associated with clinical response to ipilimumab.