Background: Although Korea and Japan have a national gastric cancer screening program, their screening intervals are different. The optimal screening interval of endoscopic screening in Japan was investigated based on the stage distributions of screen-detected gastric cancers.
Methods: Patients with gastric cancer detected by endoscopic and radiographic screenings were selected from the Niigata City Medical Association database. The stage distributions of the detected gastric cancers were compared among patients with different screening histories in both groups. Gastric cancer specific survival rates were analyzed using the Kaplan-Meier method with the log-rank test.
Results: There were 1585 and 462 subjects in the endoscopic and radiographic screening groups, respectively. In the endoscopic screening group, the stage IV proportion was lower in patients with screening history 1 and 2 years before diagnosis than in patients without screening history. Stage IV development was significantly related to the absence of screening history (p < 0.001); however, there were no differences between patients who had endoscopic screening history 2 and 3 years before diagnosis. The survival rates were not significantly different between patients with endoscopic screening 1 and 2 years previously (p = 0.7763). The survival rates were significantly higher in patients with endoscopic screening history 1 and 2 years before diagnosis than in patients without screening history (p < 0.001), and in patients with endoscopic screaming 3 years before diagnosis (P < 0.0069).
Conclusion: The endoscopic screening interval for gastric cancer can be expanded to at least 2 years based on the stage distributions of detected cancers and the patient survival rates.
Keywords: Gastric cancer screening; Screening interval; Stage distribution; Survival rate; Upper gastrointestinal endoscopy.