1. Center for Colorectal Cancer, National Cancer Center, Goyang, Korea.
2. Center for Clinical Services, Infection Disease Clinic, National Cancer Center, Goyang, Korea.
3. Cancer Biostatistics Branch, National Cancer Center, Goyang, Korea.
4. Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
5. Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.