Tea Consumption and Ovarian Cancer Risk in European and East Asian Population: A Mendelian Randomization Study

Abstract Background The association between tea consumption and ovarian cancer (OC) risk has been reported in several epidemiology studies. However, the results were inconsistent and the causal relationship remains unclear. To explore the causal relationship between tea consumption and OC risk, we performed a two-sample Mendelian randomization (MR) analysis. Methods MR analysis was conducted using two published genome wide association studies (GWASs) (25,509 cases and 40,941 controls of European population and 3,238 cases and 4,083 controls of East Asian population) and in house GWAS (2,147 OC cases and 3,179 controls of Chinese population) by inverse variance-weighted, weighted median, and MR-Egger methods. Genetic instruments of 233 single nucleotide polymorphisms (SNPs) for European population, 382 SNPs for East Asian population, and 172 SNPs for Chinese population were created. Results We identified that tea consumption has protective effect against overall OC in European population (OR = 0.95, 95%CI: 0.90–0.99, P = 2.65E-02) and Chinese population (OR = 0.96, 95%CI: 0.92-1.00, P = 3.63E-02). When stratified by histological subtype, we found that tea consumption was significantly associated with the risk of Serous OC in European (OR = 0.92, 95%CI: 0.88–0.98, P = 4.86E-03), East Asian (OR = 0.96, 95%CI: 0.92–0.99, P = 9.87E-03), and Chinese (OR = 0.94, 95%CI: 0.90–0.99, P = 1.69E-02) population. In European population, there was a reduced risk of ovarian tumors of low malignant potential (OR = 0.90, 95%CI: 0.81-1.00, P = 4.59E-02), but an increased risk of Endometrioid OC (OR = 1.14, 95%CI: 1.03–1.27, P = 1.12E-02). Conclusion Our study suggested that there might be a causal relationship between tea consumption and OC risk in both European and East Asian populations and also may provide the evidence for cancer prevention and control.