1. Department of Surgery; Osaka Medical Center for Cancer and Cardiovascular Diseases; Osaka Japan
2. Department of Surgery; Osaka University Hospital; Osaka Japan
3. Department of Surgery; Osaka International Cancer Institute; Osaka Japan
4. Osaka Medical Center for Cancer and Cardiovascular Diseases; Center for Cancer Control and Statistics; Osaka Japan
5. Osaka International Cancer Institute; Center for Cancer Control and Statistics; Osaka Japan
6. Department of Surgery; Kansai Rosai Hospital; Amagasaki Japan
7. Department of Surgery; Nara Hospital; Kinki University Faculty of Medicine; Ikoma Japan
8. Department of Surgery; Osaka Rosai Hospital; Sakai Japan
9. Department of Hepatobiliary-Pancreatic Surgery; National Hospital Organization Osaka National Hospital; Osaka Japan