[1] Shizuoka Canc Ctr, Div Gastrointestinal Oncol, 1007 Shimonagakubo, Shizuoka 4118777, Japan
[2] Shizuoka Canc Ctr, Dept Biostat, Clin Res Ctr, Shizuoka, Japan
[3] Shizuoka Canc Ctr, Div Med Oncol, 1007 Shimonagakubo, Shizuoka 4118777, Japan
[4] Oita Univ, Fac Med, Dept Med Oncol & Hematol, 1-1 Hasamauchi Idaigaoka, Oita 8795503, Japan