1. From the Division of Surgical Oncology, Department of Surgery (Sugawara, Rodriguez Franco, Franklin, Colborn, Del Chairo), University of Colorado School of Medicine, Aurora, Colorado
2. the Department of Hepatobiliary and Pancreatic Surgery, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan (Sugawara)
3. the Department of Surgical and Perioperative Sciences, Surgery, Umeå University, Umeå, Sweden (Franklin).
4. the Department of Surgery (Kirsch, Schulick), University of Colorado School of Medicine, Aurora, Colorado
5. the Department of Biostatistics and Informatics (Colborn), University of Colorado School of Medicine, Aurora, Colorado
6. the Surgical Outcomes and Applied Research Program (Colborn), University of Colorado School of Medicine, Aurora, Colorado
7. the University of Colorado Cancer Center (Del Chiaro, Schulick), University of Colorado School of Medicine, Aurora, Colorado