1. Division of Esophageal Surgery Akita University Hospital Akita Japan
2. Department of Comprehensive Cancer Control Akita University Graduate School of Medicine Akita Japan
3. Environmental Health Science and Public Health Akita University Graduate School of Medicine Akita Japan
4. Department of Gastroenterology Akita University Graduate School of Medicine Akita Japan
5. Department of Radiology Akita University Graduate School of Medicine Akita Japan
6. Department of Thoracic Surgery Akita University Graduate School of Medicine Akita Japan
7. Division of Health Services Research Center for Cancer Control and Information Services National Cancer Center Akita University Graduate School of Medicine Akita Japan