Helicobacter pylori has been recognized as a major pathogen in gastric carcinogenesis. Current guidelines recommend the H. pylori "test-and-treat" strategy for the purpose of primary and secondary gastric cancer prevention. Considering the "point of no return" theory, however, H. pylori eradication cannot reduce the risk of gastric cancer in subjects with gastric atrophy and intestinal metaplasia. The intragastric hypoacidic environment is associated with the risk of intestinal-type gastric cancer development. Recently, the secretory ability of the stomach can be measured using the serum pepsinogen (PG) assay.

This study aimed to evaluate the change of serum PGs after H. pylori eradication success and identify the optimal timing of eradication.

Inclusion Criteria:

• Gastroscopy can be performed
• Serologic markers including serum pepsinogen can be measured

Exclusion Criteria:

• Age < 20 or > 70 years
• Anemia (serum hemoglobin level < 10 g/dL)
• Severe systemic disease
• Advanced chronic liver disease
• Use of certain medications, including proton pump inhibitors, H2- receptor antagonists, or antibiotics
• History of H. pylori eradication
• History of gastric surgery
• Recent history of upper gastrointestinal bleeding

H. pylori-infected subjects who underwent an upper gastrointestinal endoscopy were enrolled in this study at a single, tertiary-care, academic medical center.