Sex and Gender Differences in Patients with Gastric Cancer: A Systematic Review

Background: Gastric cancer is a major global health concern. Although sex- and gender-based differences have been described, they are not yet well established, and the available evidence is often inconsistent. This systematic review aims to explore these differences in the incidence, clinicopathological characteristics, risk factors, treatment, and survival of gastric cancer, thereby contributing to healthcare equity. Methods: A systematic search was conducted in the main medical bibliographic databases (PubMed, Embase and Web of Science) in February 2026 following the PRISMA 2020 guidelines. Studies on gastric cancer were selected based on predefined inclusion and exclusion criteria. The results were synthesized qualitatively according to incidence, clinicopathological characteristics, risk factors, treatment outcomes, and survival. Due to the heterogeneity and predominantly observational design of the included studies, no meta-analysis or formal risk-of-bias assessment was conducted. Results: A total of 38 studies, involving more than 500,000 participants, were included. Most reported a higher incidence of gastric cancer in men, with a predominance of intestinal and well-differentiated tumors, while diffuse and poorly differentiated tumors were more common in women. Men showed higher rates of smoking, alcohol consumption, and postoperative complications. Overall survival tended to be higher in women, especially in early stages, although some studies described worse outcomes among young women. Conclusions: This review highlights relevant sex- and gender-related differences in gastric cancer and underscores the need to systematically incorporate these variables into future research to advance towards more personalized medicine. The available evidence was limited by the predominance of retrospective observational studies and heterogeneity across study designs and reported outcomes.