Systematic review and meta-analysis: Risk of gastric cancer in patients with first-degree relatives with gastric cancer

Background: Gastric cancer ranks fourth in terms of global cancer-related deaths. Timely identification of high-risk populations is crucial to reduce mortality. Although a family history of gastric cancer increases risk, European and British guidelines report weak recommendations and low-quality evidence about the management of these patients.Aim: To quantify the association in case-control studies of patients with gastric cancer with first-degree relatives with gastric cancer compared to those who do not.Methods: We conducted a systematic review and meta-analysis of case-control studies up to November 2023. Data extraction was performed independently by two reviewers. The heterogeneity of effects across studies was quantified by I-2. We calculated odds ratios (OR) with 95% confidence intervals (CI) using random effects models.Results: We included 30 studies in the systematic review. In all studies, a first-degree family history of gastric cancer represented a risk factor for gastric cancer. We included 21 studies on the risk of gastric cancer. There was a significantly increased association between gastric cancer and having first-degree relative(s) with gastric cancer, but with significant heterogeneity among studies (OR = 2.92; 95% CI 2.402-3.552; p < 0.001; I-2 = 81.85%; p < 0.001).Conclusion: This meta-analysis highlights the relevance of patients' family history of gastric cancer and the importance of this risk factor for the early detection of neoplastic conditions.