Background: In 2012, about 1 million new cases of gastric cancer were recorded worldwide, and half of these cases occurred in Eastern Asian countries. Although endoscopic screening for gastric cancer has already been introduced in Korean national programmes, evidence for mortality reduction from gastric-cancer screening using endoscopy is still unclear.

Objectives:To evaluate mortality reduction from gastric cancer by endoscopic screening, we performed a population-based cohort study where both radiographic and endoscopic screenings for gastric cancer have been conducted.

Methods:The subjects were selected from the participants of gastric cancer screening in 2 cities in Japan (i.e. Tottori and Yonago) from 2007 to 2008. The subjects were defined as participants aged 40-79 years who had no gastric cancer screening in the previous year. Follow-up of mortality was continued from the date of the first screening to the date of death or up to 31 December 2013. A Cox proportional-hazards model was used to estimate the relative risk (RR) of gastric-cancer incidence, gastric-cancer death, all cancer deaths except gastric-cancer death, and all-causes deaths except gastric-cancer death.

Results: The numbers of subjects selected for endoscopic screening was 9950 and that for radiographic screening was 4324. The subjects screened by endoscopy showed a 67% reduction of gastric cancer compared with the subjects screened by radiography (adjusted RR by sex, age group, and resident city = 0.327, 95%CI: 0.118-0.908). The adjusted RR of endoscopic screening was 0.967 (95%CI: 0.675-1.386) for all cancer deaths except gastric-cancer death and 0.928 (95%CI: 0.739-1.167) for all-causes deaths except gastric-cancer death.

Conclusions:This study indicates that endoscopic screening can reduce gastric-cancer mortality by 67% compared with radiographic screening. This is consistent with previous studies showing that endoscopic screening reduces gastric-cancer mortality.