AUTHOR=Pu Yuting , Zhu Gangcai , Xu Yimin , Zheng Siyuan , Tang Bin , Huang Huimei , Wu Irene X. Y. , Huang Donghai , Liu Yong , Zhang Xin 

TITLE=Association Between Vitamin D Exposure and Head and Neck Cancer: A Systematic Review With Meta-Analysis

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.627226

DOI=10.3389/fimmu.2021.627226

ISSN=1664-3224

ABSTRACT=<sec><title>Background</title><p>Vitamin D deficiency is a well-described preventable cause of many cancers; the association of vitamin D use with the development of head and neck cancer (HNC) is not clear. We aim to conduct a systematic review of the studies assessing the relation between vitamin D exposure and the prevention and prognosis of the HNC using meta-analysis.</p></sec><sec><title>Methods</title><p>PubMed, EMBASE, Cochrane Library, Web of Science up to 1 January 2021, and reference lists of related studies were searched. We extracted observational studies reporting the association between vitamin D (vitamin D receptor gene polymorphisms, 25-hydroxyvitamin D concentrations, and vitamin D intake) and the outcomes of interest (HNC incidence and HNC mortality) in HNC patients aged 18 or older. Fixed effects models were used to calculate pooled effect sizes and 95% confidence intervals (CIs) by RevMan (version 5.3).</p></sec><sec><title>Results</title><p>Sixteen studies with a total of 81,908 participants were enrolled in our meta-analysis. Based on the pooled genomic analysis, comparing with participants with the genotypes of <italic>Ff</italic> + <italic>FF</italic> or <italic>FF</italic>, the pooled odds ratio (OR) of participants with the genotype of <italic>ff</italic> was 0.77 (95% CI: 0.61 to 0.97) and 0.75 (0.58 to 0.97), respectively. A similar trend was noted when comparing <italic>tt</italic> with <italic>Tt</italic> + <italic>TT</italic> or <italic>TT</italic>, in which OR (95% CI) was 0.70 (0.55 to 0.90) and 0.72 (0.55 to 0.95). No significant association was identified between <italic>BsmI</italic> polymorphism and HNC. Furthermore, the OR of HNC incidence was 0.77 (0.65 to 0.92) for participants with vitamin D intake over the ones with a regular diet. High concentrations of circulated 25-hydroxyvitamin D (25-OHD) significantly decreased by 32% of HNC incidence (OR (95% CI): 0.68 (0.59 to 0.78)) and increased HNC survival (pooled hazard ratio 1.13, 1.05 to 1.22) during a 4–5 years follow-up. High concentrations of circulating 25-OHD in patients with HNC led to a decreased risk of mortality to 0.75 (0.60 to 0.94) as the follow-up extends to 8–12 years.</p></sec><sec><title>Conclusions</title><p>Elevated activities of vitamin D by diet intake, genomic polymorphisms, or circulated 25-OHD may protect people from HNC and improve the prognosis of patients with HNC.</p></sec><sec><title>Systematic Review Registration</title><p>PROSPERO, identifier CRD42020176002 (<uri xlink:href="https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=176002" xmlns:xlink="http://www.w3.org/1999/xlink">https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=176002</uri>).</p></sec>