Updated overview of current biomarkers in head and neck carcinoma

Table 1 Comparison of different biomarkers of head neck squamous cell carcinoma

Marker	Mechanism	Type of specimen	Role	Limitations
Chemokine receptors	Increased expression in tumor tissue	Biopsy specimen	Prognosis and metastasis	Clinical validation by further research required
HPV	DNA associated HNSCC, oncoprotein production	Tumor tissue	Diagnosis and prognosis	Lack of sensitivity and specificity
MSI	LOH in tumor derived DNA	Mouth washings/lesion brushings	Detection of pre-malignant lesion	Lack of uniformity of method
Methylation markers	Gene inactivation following hypermethylation in promoter region	Saliva/serum	Early detection	Lack of sensitivity/specificity, complex methodology
MMPs	Provide conducive microenvironment for tumor growth, degrade ECM promoting tumor migration	Tumor tissue/saliva	Early detection	Poor specificity
Interleukins	Participate in process of tumor growth and metastasis	Tumor tissue/cell line supernatants/saliva/serum	Early and convenient biomarker	Lack of sensitivity and specificity
miRNA	Role in regulation of gene expression	Tumor tissue/saliva	Early detection	Clinical validation required
MAGE	Suppresses apoptosis	Biopsy specimen/saliva	Prognosis and in selecting targeted immunotherapy	Clinical validation required
Centrosome abnormalities	Mutation due to hyperamplification	Tumor tissue	Early detection	Further research required to understand molecular mechanism
Actin and myosin	Increased expression leading to greater invasiveness	Tumor tissue/saliva	Early detection	Lack of sensitivity and specificity
Cytokeratins	Over-expression associated with tumor progression	Tumor tissue/saliva/serum	Early detection and prognosis	Clinical validation required
p53	Mutation affects apoptosis/repair of malignant cells	Tumor tissue	Diagnosis, prognosis, convenient marker	Complete role in HNSCC yet to be deciphered
eIF4E	Overexpression associated with tranformation of fibroblasts and epithelial cells	Tumor tissue	Prognostic indicator	Lack of sensitivity and specificity

HNSCC: Head and neck squamous cell carcinoma; MSI: Microsatellite instability; LOH: Loss of heterozygosity; MMP: Metalloproteinase; ECM: Extracellular matrix; MAGE: Melanoma-associated gene; HPV: Human papilloma virus; miRNA: Micro RNA; eIF4E: Eukaryotic translation factor 4E.