1. Department of Surgery, Kyoto University, Kyoto, Japan
2. Department of Healthcare Epidemiology, School of Public Health, Graduate School of Medicine, Kyoto University, Kyoto, Japan
3. Centre for Innovative Research for Communities and Clinical Excellence, Fukushima Medical University, Fukushima, Japan
4. Department of Public Health, University of Tokyo Graduate School of Medicine, Tokyo, Japan
5. Department of Surgery, Tochigi Cancer Centre, Utsunomiya, Tochigi, Japan
6. Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan