Background: There are more than 30 genes polymorphisms associated with risk and survival rate of oral squamous cell carcinoma (OSCC). Nevertheless, different ethnicity could show different genotype and allele as the risk factor.
Objectives: The aim of this study was to summarize and clarify the association between gene polymorphisms in different ethnicities with OSCC.
Methods: A systematic review was performed through English literature search in PubMed database with keywords: ‘oral squamous cell carcinoma’ and ‘gene polymorphism’. Seventeen eligible case control studies published from year 2004 to 2012 were retrieved with a total of 2537 patients, 2344 controls, and 6 gene polymorphisms that had been investigated in more than 1 ethnicity. The genes were P53 codon 72, Fibroblast growth factor receptor 4 (FGFR4), Cycolooxygenase-2 (COX-2), Tumor necrosis factor-alpha (TNF-alpha), Vascular endothelial growth factor (VEGF), and Vitamin D receptor (VDR).
Results: P53 Pro/Pro had 3.51-fold increased risk of OSCC in South Indian, ( p = 0.005) but not in Taiwanese. COX-2 765G > C polymorphism increased OSCC risk in South Indian ( p = 0.0001), in contrast with Taiwanese. TNF-alpha; 308G allele was associated with increased risk in Taiwanese ( p = 0.02), differed from Caucasian. FGFR4 Arg388 allele reduced survival in both German and Japanese ( p < 0.05). VEGF 936 T allele worsened prognosis in Caucasian ( p = 0.002), which was the opposite of Taiwanese. VDR FokI ff weakened survival in Caucasian ( p = 0.012) but not significant in Indian population. VDR Taq I T allele was the risk factor in Egyptian ( p = 0.003) but not in Turkish.
Conclusion: FGFR Arg388 allele decreased survival rate in 2 ethnicities whereas other genes showed different genotype or had no significant role. Extensive studies involving larger population and various ethnicities are needed to confirm particular genes as OSCC prognostic marker.
Key words : oral squamous cell carcinoma; gene polymorphism; risk factor; prognosis