A Longitudinal Study of Premalignant Gastric Lesions and Early Onset Gastric Cancer Among Young Adults in Central Saudi Arabia.

Gastric cancer traditionally affects older adults, and its precursor lesions and risk factors are well-documented in this population. Helicobacter pylori (H. pylori) infection remains highly prevalent in Saudi Arabia and contributes to gastric pathology. However, early-onset gastric cancer (EOGC), diagnosed in individuals aged ≤ 45 years, presents unique challenges and remains poorly understood in young populations. Therefore, we conducted an observational cohort study using a prospective longitudinal design (2021-2024) involving 1823 Saudi nationals aged 18-45 years who underwent zoom high-definition chromoendoscopy to evaluate the prevalence of premalignant gastric lesions (PGLs) and EOGC. We found a high H. pylori prevalence (78.0%) with PGLs in 1.9% of participants and EOGC-adenocarcinoma in 0.7% of patients. All EOGC cases arose from dysplasia, with most PGLs being classified as OLGA/OLGIM stage II/III. Multiple risk factorswere significantly associated with PGLs and EOGC, including H. pylori infection (p = 0.022), increasing age (p < 0.001), a family history of gastric cancer (p < 0.001), poor dietary habits (p < 0.001), obesity (p < 0.001), and smoking (p < 0.001). Additional EOGC risk factors include dage of 36-45 years (p = 0.018), EBV infection (p = 0.016), and diabetes mellitus (p = 0.001). These findings demonstrate the notable presence of PGLs and EOGC in young Saudi adults and emphasize the importance of early detection and risk factor management in this vulnerable population.