Endoscopic gastric cancer screening in the Republic of Korea

In Korea, gastric cancer (GC) remains the leading cause of cancer incidence (17.8%) in men and the fourth most common cancer (8.9%) in women in 2013. The Korean government established the National Cancer Screening Program (NCSP) in 1999 for Medical Aid recipients and gradually expanded to include all the population aged 40 or more. The participation rates increased from 7.4% in 2002 to 45.4% in 2011. NCSP provides gastric cancer screening every two years and participants can choose either upper-gastrointestinal series (UGIS) or endoscopy according to their preference. The proportion of participants who underwent endoscopy increased dramatically from 31.15% in 2002 to 72.55% in 2011. By NCSP data between 2002 and 2005, gastric cancer detection rates were 0.68 and 2.61 per 1,000 UGIS or endoscopy screenings, respectively. The sensitivities of UGIS and endoscopy screening to detect gastric cancer were 36.7 and 69.0%, respectively, and their specificities were 96.1 and 96.0%, respectively. Mortality reduction is the key parameter in evaluating the efficacy of screening program. According to screening modality, the ORs of death from GC were 0.53 for endoscopy and 0.98 for UGIS. As the number of endoscopic screening tests performed per subject increased, the ORs of death from GC decreased: 0.63, 0.32, and 0.19 for once, twice, and three or more times, respectively. A nationwide GC screening program using endoscopy in Korea seems effective in reducing GC mortality.