1. Department of Palliative Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
2. Department of Psychosomatic Medicine, Kindai University Faculty of Medicine, Osakasayama, Japan
3. Department of Psycho-Oncology, National Cancer Center Hospital, Tokyo, Japan
4. JORTC Data Center, Tokyo, Japan
5. Department of Palliative Medicine, Kobe University Graduate School of Medicine, Kobe, Japan