Association between promoter polymorphisms of OPN gene and cancer risk: a meta-analysis

BACKGROUND: Results of the association between polymorphisms of osteopontin (OPN) gene promoter region and risk of cancer were inconclusive. The aim of this meta-analysis was to elucidate whether OPN promoter polymorphisms were associated with cancer risk. METHODS: Electronic databases including PubMed, Web of Science, and Chinese National Knowledge Infrastructure were systematically searched. Odd ratios (ORs) and their 95% confidential interval (CI) were used to assess the strength of association between OPN promoter polymorphisms and cancer risks. RESULTS: Nine studies were finally included in this meta-analysis. For OPN rs17524488 polymorphism, carriers of GG or -/G genotype were significantly associated with increased cancer risk compared with wild-type -/- carriers, respectively (GG vs -/-: OR =1.40, 95% CI =1.03–1.91, P=0.033; -/G vs -/-: OR =1.22, 95% CI =1.07–1.40, P=0.002). Additionally, G allele was significantly associated with increased cancer risk compared with (-) allele (OR =1.21, 95% CI =1.04–1.40, P=0.016). However, no significant association was observed of OPN rs11730582 polymorphism and cancer risk (CC vs TT: OR =0.98, 95% CI =0.49–1.97, P=0.964; CT vs TT: OR =0.88, 95% CI =0.54–1.43, P=0.610). CONCLUSION: Carriers of GG or -/G genotype of OPN promoter rs17524488 (-156-/G) polymorphism might be associated with increased risk of cancer compared with wild-type -/- carriers, respectively. However, no significant association was observed between OPN promoter rs11730582 (-443C/T) polymorphism and risk of cancer.