Modern molecular biomarkers of head and neck cancer. Part I. Epigenetic diagnostics and prognostics: Systematic review

INTRODUCTION: Nearly half of the head and neck cancer cases are diagnosed in late stages. Traditional screening modalities have many disadvantages. The aim of the present article was to review the scientific literature about novel head and neck cancer diagnostics - epigenetic biomarkers. EVIDENCE ACQUISITION: A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed database. Authors conducted the search of articles in English language published from 2004 to 2015. EVIDENCE SYNTHESIS: A total of thirty three relevant studies were included in the review. Fifteen of them concerned DNA methylation alterations, nine evaluation of abundancies in histone expressions and nine miRNA expression changes in HNC. CONCLUSIONS: Considerable number of epigenetic biomarkers have been identified in both tumor tissue and salivary samples. Genes with best diagnostic effectiveness rates and further studying prospects were: TIMP3, DCC, DAPK, CDH1, CCNA1, AIM1, MGMT, HIC1, PAX1, PAX5, ZIC4, p16, EDNRB, KIF1A, MINT31, CD44, RAR?, ECAD. Individual histone and miRNA alterations tend to be hnc specific. Prognostic values of separate biomarkers are ambiguous. No established standards for molecular assay of head and neck cancer was found in order to elude the paradoxical results and discrepancies in separate trials.