[1] Kyushu Univ, Beppu Hosp, Dept Surg, Beppu, Oita 8740838, Japan
[2] Iwate Med Univ, Dept Surg, Morioka, Iwate 020, Japan
[3] Univ Tokyo, Natl Canc Ctr Hosp, Dept Gastr Surg Div, Kashiwa, Chiba, Japan
[4] Univ Tokyo, Grad Sch Frontier Sci, Dept Med Genome Sci, Kashiwa, Chiba, Japan
[5] Teikyo Univ, Sch Med, Dept Surg, Tokyo 173, Japan
[6] Osaka Univ, Grad Sch Med, Dept Surg Gastroenterol, Suita, Osaka, Japan
[7] Hyogo Coll Med, Dept Digest Surg, Kobe, Hyogo, Japan