1. Department of Palliative Care and Rehabilitation Medicine, The University of Texas MD Anderson Cancer Center;, Houston, Texas, USA;
2. The University of Texas Health Science, Medical School, Division of Geriatrics and Palliative Medicine, Lyndon B. Johnson General Hospital, Harris Health System;, Houston, Texas, USA;
3. Department of General Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA;
4. Centre de Soins Palliatifs, Centre Hospitalier de Lyon Sud, Hospices Civils de Lyon;, Lyon, France
5. Department of Biostatistics, The University of Texas MD Anderson Cancer Center;, Houston, Texas, USA;