1. Department of Internal Medicine, Kangdong Sacred Heart Hospital, Hallym University, Seoul, Republic of Korea;
2. Departments of Palliative Care and Rehabilitation Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
3. Division of Hematology-Oncology, Department of Internal Medicine, Daejeon St. Mary's Hospital College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea;
4. Department of Palliative Care, Mercy Medical Group, Dignity Health Medical Foundation, Sacramento, California, USA
5. Departments of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
6. Departments of Gynecologic Oncology and Reproductive Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA;