1. Department of Gastroenterology and Hepatology, Yokohama City University, Yokohama, Japan
2. Department of Palliative Medicine, Yokohama City University, Yokohama, Japan
3. Department of Oncology, Yokohama City University, Yokohama, Japan
4. Department of Palliative Medicine, National Cancer Center Hospital, Tokyo, Japan
5. Department of Data Science, Yokohama City University Graduate School of Medicine, Yokohama, Japan
6. Department of Biostatistics, Japanese Organization for Research and Treatment of Cancer (JORTC), JORTC Data Center, Tokyo, Japan