Gene polymorphisms and risk of head and neck squamous cell carcinoma: a systematic review

Background: Exposure to the same environmental factors in different people have resulted in different susceptibility to head and neck squamous cell carcinoma (HNSCC), which suggests genetic variation may be a risk factor for the development of HNSCC. So, the aim was to review literatures on the association between gene polymorphisms and risk of HNSCCs.Materials and methods: This systematic review included all articles on the impact of gene polymorphisms on risk and sus-ceptibility to HNSCC published till September 2021 using PubMed, Web of science, SCOPUS, Google Scholar and Cochrane library databases.Results: Of 1163 initial searched articles, 77 articles were eligible to include in this review. Studies were categorized based on gene functions. In each category, studied gene polymorphisms related to growth control genes, cell cycle control, apoptosis, DNA repair genes, carcinogen-metabolizing enzymes, alcohol-metabolizing genes, antioxidant gene, inflammatory cytokine, transcription factor, tumor immunity, folate metabolism, and tumor suppressor gene were discussed separately. Among the polymorphisms that are often significantly associated with HNSCC risk are: GSTM1 null, GSTT1 null, CYP2D6 *4,XRCC1 Ar-g194Trp and Arg399Gln, ERCC1 C8092A, XPD Lys751Gln,XRCC3Thr241Met, P53 codon 72 and MTHFR C677T polymorphisms.Conclusion:Varied and contradictory results have been reported in different studies regarding the association of gene poly-morphisms with HNSCC risk. To conclude about this association and to overcome these contradictions, it is necessary to use the results of existing meta-analyses or to perform new or updated meta-analyses.