1. Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Seoul, Korea
2. Department of Medicine, Kyung Hee University College of Medicine, Seoul, Korea
3. Department of Medicine, Korea University College of Medicine, Seoul, Korea
4. Department of Medicine, Inje University College of Medicine, Seoul, Korea
5. Department of Medicine, Soonchunhyang University College of Medicine, Seoul, Korea
6. Department of Medicine, Yonsei University College of Medicine, Seoul, Korea
7. Department of Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
8. Department of Medicine, Seoul National University Hospital, Seoul, Korea
9. Department of Medicine, Dankook University College of Medicine, Cheonan, Korea
10. Department of Medicine, Chungbuk National University College of Medicine, Cheongju, Korea
11. Department of Medicine, Hanyang University College of Medicine, Seoul, Korea
12. Center for Gastric Cancer, National Cancer Center, Goyang, Korea
13. Cancer Early Detection Branch, National Cancer Center, Goyang, Korea