Epigenetics in the diagnosis and prognosis of head and neck cancer: A systematic review

Background

Aberrant epigenetic modifications significantly develop and progress human malignancies including head and neck squamous cell carcinoma (HNSCC). Taking into account issues of late diagnosis and poor prognosis associated with HNSCC, this systematic review is designed to provide an up-to-date insight of epigenetic changes in the management of HNSCC.

Methods

All studies that assessed the diagnostic and prognostic utilities of epigenetic changes (DNA methylation and histone modifications) among patients diagnosed with HNSCC or oral potentially malignant disorders (OPMDs) were considered for inclusion till June 2023. Pre-defined Medical Subject Headings terms were used to search Web of Science, Pubmed, Scopus and Embase Ovid databases.

Results

Twenty-five studies were deemed eligible for inclusion with a total number of 3790 samples (2123 HNSCCs, 334 OPMDs and 1333 as controls). DNA methylation was investigated in 18 studies while the role of histone modifications was assessed in seven studies. The most investigated biomarkers among the studies were H3, DAPK and TIMP3. The diagnostic accuracy of the epigenetic biomarkers in detecting HNSCC was assessed in eight studies where the following biomarkers showed the highest area under the curve values: TIPM3, DCC, DAPK, SEPT9, SHOX9, HOXA9 and TRH. None of the studies assessed the predictability of the epigenetic biomarkers in HNSCC and OPMDs.

Conclusion

Although initial promising results were seen using the epigenetic biomarkers in the early detection of HNSCC, the limited number of patients and the absence of well-designed longitudinal studies limit the clinical applicability of the outcomes.