This article highlights the role of meta-analysis as a statistical method for quantitatively summarizing existing research and reconciling conflicting findings. It discusses literature search methods for meta-analysis, the selection and interpretation of statistical models, and publication bias. Meta-analysis allows for the statistical consideration of homogeneity and heterogeneity among studies. Determining homogeneity and heterogeneity is crucial for selecting the appropriate meta-analysis model. Systematic reviews and meta-analyses provide a high level of evidence on treatment efficacy, especially when they include multicenter and multinational studies. In the case of well-researched disorders such as digestive cancer, meta-analysis can be useful in generalizing findings from existing papers, draw conclusions, and evaluate related medical technologies. Furthermore, these findings can be used to propose or enhance standards of care.