[1] Seoul Natl Univ, Seoul Natl Univ Hosp, Canc Res Inst, Coll Med, Seoul, South Korea
[2] Univ Milan, Fdn IRCCS Ist Nazl Tumori, Milan, Italy
[3] UCL, Res Dept Oncol, Inst Canc, London, England
[4] Kyorin Univ, Dept Med Oncol, Sch Med, Tokyo, Tokyo, Japan
[5] Natl Taiwan Univ Hosp, Dept Med Oncol, Taipei, Taiwan
[6] Natl Canc Ctr Hosp East, Hepatobiliary & Pancreat Oncol Dept, Kashiwa, Chiba, Japan
[7] Univ Texas MD Anderson Canc Ctr, Gastrointestinal Med Oncol, Houston, TX 77030 USA
[8] Mainz Univ Hosp, Dept Gastroenterol, Hepatol, Mainz, Germany
[9] Sungkyunkwan Univ, Samsung Med Ctr, Sch Med, Seoul, South Korea
[10] Peking Univ, Key Lab Carcinogenesis & Translat Res, Dept Gastrointestinal Oncol, Minist Educ Beijing,Canc Hosp & Inst, Beijing, Peoples R China
[11] Univ Ulsan, Med Ctr, Coll Med, Seoul, South Korea
[12] Merck KGaA, Biostat, Darmstadt, Germany
[13] Merck Biopharma, Biostat, Tokyo, Japan
[14] Mayo Clin, Ctr Canc, Oncol, Scottsdale, AZ USA