[1] Chiba Univ, Grad Sch Med, Dept Med & Clin Oncol, Chuo Ku, Chiba 2608670, Japan
[2] Social Insurance Funabashi Chuo Hosp, Funabashi, Chiba 2738566, Japan
[3] Matsudo City Hosp, Matsudo, Chiba 2718511, Japan
[4] Saiseikai Narashino Hosp, Narashino, Chiba 2750006, Japan
[5] Kikkoman Hosp, Noda, Chiba 2780005, Japan
[6] Natl Hosp Org Chiba Med Ctr, Chiba 2630042, Japan
[7] Sannou Hosp Med Ctr, Chiba 2630002, Japan
[8] Kimitsu Chuo Hosp, Kisarazu 2928535, Japan