Gastric cancer (GC) is the first cancer-related cause of death in Chile; however, no plan for GC early detection has been implemented in this country. The OLGA system characterizes gastritis from stages 0 to IV according to the risk of developing GC based on H. pylori infection, atrophy, metaplasia and GC. In this study, the performance of the OLGA system was evaluated in 485 Chilean patients receiving routine endoscopy to improve the detection of early GC or preneoplastic lesions. The results showed that OLGA scores, atrophy, metaplasia and GC increased significantly with age (p < 0.001). Conversely, H. pylori infection was higher in younger groups (p < 0.05). All gastric lesions were more frequent in men than women. The majority of patients with atrophy also had metaplasia (99%, p < 0.0001). Patients with H. pylori infection had more gastric atrophy and metaplasia than those without infection (p < 0.05). Of the 485 patients, 21 (4.3%) had GC, being 2.3 times more frequent among men than women and about 2/3 (14) were in OLGA stage ≥2. In addition, 19 (90%) GC patients had atrophy and 18 (85%) had metaplasia (p < 0.001). In conclusion, the OLGA system facilitated the evaluation of GC precursor lesions particularly in patients with an OLGA score > 2 between 45 and 56 years old, because this group showed atrophy and intestinal metaplasia more frequently. Therefore, biennial endoscopic surveillance of patients with an OLGA >2 can be an important health policy in Chile for diagnosing GC in its early stages and reducing mortality over the next two decades.
Keywords: Chilean population; Gastric atrophy; Gastric cancer; Helicobacter pylori infection; Metaplasia; The OLGA system.