[1] Seoul Natl Univ, Coll Med, Div Hematol & Med Oncol, Dept Internal Med,Bundang Hosp, 166 Gumi Ro, Seongnam 463707, Gyeonggi Do, South Korea
[2] Seoul Natl Univ, Dept Internal Med, Div Hematol & Med Oncol, Bundang Hosp, Seongnam, South Korea
[3] Yonsei Univ Hlth Syst, Palliat Care Ctr, Yonsei Canc Ctr, Seoul, South Korea
[4] Yonsei Univ Hlth Syst, Yonsei Canc Ctr, Div Med Oncol, Seoul, South Korea
[5] CHA Bundang Med Ctr, Div Med Oncol, Seongnam, South Korea
[6] Univ Texas MD Anderson Canc Ctr, Dept Palliat Rehabil & Integrat Med, Houston, TX 77030 USA