[1] Ajou Univ, Dept Surg, Sch Med, Suwon, South Korea
[2] Seoul Natl Univ Hosp, Dept Internal Med, Seoul, South Korea
[3] Seoul Natl Univ, Canc Res Inst, Seoul, South Korea
[4] Univ Ulsan, Asan Med Ctr, Dept Oncol, Coll Med, Seoul, South Korea
[5] Inst Nacl Enfermedades Neoplas, Dept Med Oncol, Lima, Peru
[6] Sungkyunkwan Univ, Samsung Med Ctr, Dept Med, Div Hematol Oncol,Sch Med, Seoul, South Korea
[7] Gachon Univ, Dept Internal Med, Div Med Oncol, Gil Med Ctr, Incheon, South Korea
[8] Chosun Univ, Chosun Univ Hosp, Dept Surg, Coll Med, Gwangju, South Korea
[9] Korea Univ, Guro Hosp, Dept Internal Med, Div Hematol Oncol,Coll Med, Seoul, South Korea
[10] Yonsei Univ, Gangnam Severance Hosp, Dept Surg, Coll Med, Seoul, South Korea
[11] Kyungpook Natl Univ, Chilgok Hosp, Sch Med, Dept Surg, Daegu, South Korea
[12] Asan Med Ctr, Dept Clin Epidemiol & Biostat, Seoul, South Korea
[13] Univ Ulsan, Asan Med Ctr, Dept Surg, Div Breast Surg,Coll Med, Seoul, South Korea