Folate Mediated One Carbon Metabolism in Head and Neck Squamous Cell Carcinoma: A Systematic Review

Abstract

Introduction: Head and neck cancer (HNC) is one of the most prevalent cancers of upper aerodigestive tract, with squamous cell carcinomas accounting for the majority of cases. Vitamin B such as folate has been associated with carcinogenesis. Folate is essential for one carbon metabolism, which involves the transfer of one carbon units for Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) production, amino acid metabolism and methylation. Aim: To evaluate the association of folate mediated One carbon metabolism with Head and Neck Squamous Cell Carcinoma (HNSCC). Materials and Methods: For this systematic review, Electronic bibliographic databases search of PubMed, Google Scholar and Scopus was done. The electronic search was performed between November 15th to November 30th, 2020 by two researchers independently. All original research, observational studies, full text articles, in which blood samples or questionnaires or both, focused on the assessment of folate mediated one carbon metabolism in HNSCC, published upto November 2020 were reviewed. Four studies published from 2005 to 2019 were included in which three studies were case-control and one study was a comparative cross-sectional study. This systematic review was carried out by two reviewers, using Preferred Reporting Items for Systematic reviews and Meta Analyses (PRISMA) checklist and the New Castle Ottawa Scale (NOS) for quality assessment. Results: In this systematic review, total of four studies included, had 1504 HNSCC patients and 2970 Controls. One study was reported from Nigeria, one from the European countries, one from Japan, and one from the United States of America (USA). One study had a quality score of 8 whereas 3 studies had 7, considering all the four studies included are of good quality. Conclusion: Significant low levels of serum folate was present in HNSCC when compared to controls. Serum folate levels can differ due to tumor growth and subsequent metabolic changes, or they may precede and accelerate tumor progression.