KIT, NRAS and BRAF mutations in head and neck (upper aerodigestive tract) mucosal melanoma (a study of 21 cases)

Abstract

Objective. Determination of mutation rates in KIT, NRAS and BRAF genes in 21 samples of mucosal melanoma of the upper aerodigеstive tract.Background. Head and neck mucosal melanomas (or upper aerodigestive tract mucosal melanomas) are rare and aggressive tumors of melanocytic origin. Head and neck mucosal melanoma (HNMM) comprises over 50 % of all mucosal melanomas. The aim was to determine the KIT, NRAS and BRAF mutation frequencies in 21 series of primary HNMM.Methods. Microdissected tumour cells were used from 21 formalin-fixed paraffin-embedded tumours. The tumour cells were screened for KIT, NRAS and BRAF mutations by direct sequencing.Results. Overall, 19 % (4 out of 21) of HNMMs harboured KIT, NRAS or BRAF mutations. Mutations in these oncogenes occurred in a mutuаlly exclusive manner. Both NRAS and BRAF mutations were identified at a similar frequency of 4,75 % each (1 and 1 out of 21), whereas KIT mutations were detected in 9,5 % (2 out of 21) of the HNMMs. KIT mutations were located in exon 11.Conclusion. Our findings shоw that NRAS and BRAF mutations, which are aсcessible for present targeted thеrapies, are only rarеly present in HNMMs, whereas KIT mutations seem to be relatively more frequent.

Keywords

• голова и шея
• верхние дыхательные и пищеварительные пути
• меланома слизистых оболочек
• меланома кожи
• таргетная терапия
• мутации генов braf
• nras
• kit