1. Department of Colon and Rectal Surgery, Sunlin Hospital, Pohang, Korea.
2. Center for Colorectal Cancer, Research Institute & Hospital, National Cancer Center, Goyang, Korea.
3. Department of Colon and Rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea.
4. Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.