Mucosal Melanoma Targeted Sequencing Study (UCSF)

Mucosal melanoma is a deadly disease that carries the worst prognosis amongst subtypes of melanoma. Like all melanomas, mucosal melanomas are frequently driven by activating mutations in the MAPK and/or PI3K pathways; however, unlike melanomas that arise on sun-exposed skin, mucosal melanomas harbor few point mutations. Instead, most somatic alterations involve structural alterations, which appear early during tumor progression. Molecular studies in mucosal melanoma generally only profile point mutations without interrogating copy number alterations, and pathogenic mutations are only found in 30% of cases. We sequenced 38 mucosal melanomas, and in addition to profiling point mutations, we looked for copy number alterations that amplify oncogenes or delete tumor suppressors.]]> Nimblegen 1Nimblegen 2Nimblegen 3Nimblegen 4Formalin fixed, paraffin embedded (FFPE) and mounted tumor slide samples were screened by UCSF pathologists using hematoxylin and eosin (H&E) stained slides. Tumors were assessed for melanoma status, mucosal origin, epithelial involvement, and metastatic status. Of the 38 mucosal melanoma samples, 26 were primary mucosal melanomas, 4 were metastatic, and 8 were mucosal melanoma of indeterminate stage. Matched normal FFPE skin biopsy samples were available for 5 samples. ]]>