[1] Toho Univ, Fac Med, Dept Clin Oncol, Tokyo, Japan
[2] Toho Univ, Dept Surg Omori, Div Gen & Gastroenterol Surg, Tokyo, Japan
[3] Jikei Univ, Sch Med, Dept Surg, Tokyo, Japan
[4] NTT Med Ctr Tokyo, Tokyo, Japan
[5] Natl Hosp Org, Tokyo Med Ctr, Tokyo, Japan
[6] Japanese Red Cross Med Ctr, Dept Gastroesophageal Surg, Tokyo, Japan
[7] Toho Univ, Ohashi Med Ctr, Dept Surg, Tokyo, Japan