DNA methylation profiling of salivary gland tumors

Tumors of the major and minor salivary gland encompass a diverse spectrum of diagnostically challenging neoplasms. Recent studies have identified several gene fusions and somatic mutations that are specific or highly enriched in certain salivary gland tumor entities and can assist histopathological diagnosis. Still, there is an unmet need to identify additional diagnostic biomarkers for entities lacking specific alterations. In this study, we collected a comprehensive cohort of 363 cases encompassing 20 different salivary gland tumor entities and explored the potential of DNA methylation to classify these tumors. We were able to show that most entities show specific epigenetic signatures and present a machine learning algorithm that can be used to classify diagnostically challenging cases. 363 specimens were analyzed using the MethylationEPIC BeadChip