摘要AIM:To compare the cost and accuracy of upper gastrointestinal (GI) X-ray and upper endoscopy for diagnosis of gastric cancer using data from the 2002-2004 Korean National Cancer Screening Program (NCSP).METHODS:The study population included 1 503 646 participants in the 2002-2004 stomach cancer screening program who underwent upper GI X-ray or endoscopy.The accuracy of screening was defined as the probability of detecting gastric cancer.We calculated the probability by merging data from the NCSP and the Korea Central Cancer Registry.We estimated the direct costs of the medical examination and the tests for upper GI X-ray,upper endoscopy,and biopsy.RESULTS:The probability of detecting gastric cancer via upper endoscopy was 2.9-fold higher than via upper GI X-ray.The unit costs of screening using upper GI X-ray and upper endoscopy were $32.67 and $34.89,respectively.In 2008,the estimated cost of identifying one case of gastric cancer was $53 094.64 using upper GI X-ray and $16 900.43 using upper endoscopy.The cost to detect one case of gastric cancer was the same for upper GI X-ray and upper endoscopy at a cost ratio of 1:3.7.CONCLUSION:Upper endoscopy is slightly more costly to perform,but the cost to detect one case of gastric cancer is lower.