Objective To explore the causal association between radiation exposure and risk of head and neck cancer using Mendelian randomization (MR) method. Methods Genome-wide association studies of radiation exposure and head and neck cancer in the public database IEU OpenGWAS were identified, and single nucleotide polymorphisms (SNPs) were screened as instrumental variables. Two-sample MR analyses were performed using random-effect inverse variance weighted (IVW), fixed-effect IVW, weighted median, and MR-Egger methods to assess the causal association between radiation exposure and risk of head and neck cancer. Outliers were tested using the MR-PRESSO method, and heterogeneity was assessed using the Cochran Q test. MR-Egger regression intercept was utilized to detect gene-level pleiotropy, and a leave-one-out sensitivity analysis was conducted to evaluate the robustness of the study results. Results96 valid SNPs were included as instrumental variables. The analysis results of random-effect IVW method, fixed-effect IVW method, and weighted median method all showed that radiation exposure was associated with an increased risk of head and neck cancer [odds ratio and 95% confidence interval: 1.139 (1.065, 1.218), 1.139 (1.068, 1.215), and 1.141 (1.039, 1.253); P<0.05]. Heterogeneity testing did not reveal significant heterogeneity, MR-Egger regression analysis did not find gene level pleiotropy, and the leave-one-out method did not find a single SNP significantly affecting the overall estimation results. Conclusion Radiation exposure increases the risk of head and neck cancer, but this conclusion still needs further validation in more high-quality, large sample studies.
ObjectiveTo explore whether there is a causal relationship between intestinal flora and esophageal cancer. MethodsSummary statistics of intestinal flora and esophageal cancer were obtained from the Genome-wide Association Studies (GWAS) database. Five methods, including inverse variance weighted (IVW), weighted median estimation, Mendelian randomization (MR)-Egger regression, single mode, and weighted mode, were used for analysis, with IVW as the main analysis method. Sensitivity analysis was used to evaluate the reliability of MR results. ResultsIn the IVW method, Oxalobacteraceae [OR=1.001, 95%CI (1.000, 1.002), P=0.023], Faecalibacterium [OR=1.001, 95%CI (1.000, 1.002), P=0.028], Senegalimassilia [OR=1.002, 95%CI (1.000, 1.003), P=0.006] and Veillonella [OR=1.001, 95%CI (1.000, 1.002), P=0.018] were positively correlated with esophageal cancer, while Burkholderiales [OR=0.999, 95%CI (0.998, 1.000), P=0.002], Eubacterium oxidoreducens [OR=0.998, 95%CI (0.997, 0.999), P=0.038], Romboutsia [OR=0.999, 95%CI (0.998, 1.000), P=0.048] and Turicibacter [OR=0.998, 95%CI (0.997, 0.999), P=0.013] were negatively correlated with esophageal cancer. Sensitivity analysis showed no evidence of heterogeneity, horizontal pleiotropy and reverse causality. ConclusionOxalobacteraceae, Faecalibacterium, Senegalimassilia and Veillonella increase the risk of esophageal cancer, while Burkholderiales, Eubacterium oxidoreducens, Romboutsia and Turicibacter decrease the risk of esophageal cancer. Further studies are needed to explore how these bacteria affect the progression of esophageal cancer.