Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. Electronic address: cyoo.amc@gmail.com.