[1] Natl Canc Ctr, Gastrointestinal Oncol Div, Chuo Ku, Tokyo 1040045, Japan
[2] Natl Canc Ctr Hosp E, Dept Gastrointestinal Med, Chiba 2778577, Japan
[3] Shizuoka Canc Ctr, Gastrointestinal Oncol Div, Shizuoka 4118777, Japan
[4] Aichi Canc Ctr Cent Hosp, Dept Clin Oncol, Chikusa Ku, Aichi 4648681, Japan
[5] Osaka Med Coll, Dept Gastrointestinal Med, Osaka 5698686, Japan
[6] Tochigi Canc Ctr, Div Clin Oncol, Utsunomiya, Tochigi 3200834, Japan
[7] Kinki Univ, Dept Surg, Osaka 5898511, Japan
[8] Bristol Myers KK, Res & Dev, Shinjuku Ku, Tokyo 1631328, Japan