1. Joint Committee for Nationwide Survey on Colorectal Liver Metastasis Tokyo Japan
2. Department of Hepato‐Biliary‐Pancreatic and Breast Surgery Ehime University Graduate School of Medicine Toon Japan
3. Department of Gastroenterological Surgery New Tokyo Hospital Matsudo Japan
4. Department of Surgery Yamaga City Medical Center Kumamoto Japan
5. Department of Surgery Sano City Hospital Sano Japan
6. Department of Surgery Institute of Gastroenterology Tokyo Women’s Medical University Tokyo Japan
7. Department of Surgery Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital Tokyo Japan
8. Department of Gastroenterological Surgery Yokohama City University Graduate School of Medicine Yokohama Japan
9. Department of Surgery Hepato‐Biliary‐Pancreatic Surgery Division Graduate School of Medicine University of Tokyo Tokyo Japan
10. Department of Surgery Teikyo University School of Medicine Tokyo Japan
11. Department of Hepatobiliary and Pancreatic Surgery National Cancer Center Hospital East Kashiwa‐shi Japan
12. Department of Pediatrics Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital Tokyo Japan
13. Department of Surgery Teikyo University Hospital, Mizonokuchi Kawasaki Japan
14. Department of Gastrointestinal Chemotherapy Cancer Institute Hospital of Japanese Foundation for Cancer Research Tokyo Japan
15. Department of Biomedical Statistics and Bioinformatics Graduate School of Medicine Kyoto University Shogoin Japan
16. International University of Health and Welfare Mita Hospital Tokyo Japan
17. Tokyo Medical and Dental University Tokyo Japan