[1] Oita Univ, Fac Med, Dept Gastroenterol & Pediat Surg, Oita 87011, Japan
[2] Natl Canc Ctr, JCOG Operat Off, Tokyo 104, Japan
[3] Natl Canc Ctr, JCOG Data Ctr, Tokyo 104, Japan
[4] Kitasato Univ, Sch Med, Sagamihara, Kanagawa 228, Japan
[5] Tokyo Med & Dent Univ, Grad Sch, Dept Surg Oncol, Tokyo, Japan
[6] Nerima Hikarigtaoka Hosp, Dept Surg, Tokyo, Japan
[7] Natl Canc Ctr, Div Colorectal Surg, Tokyo 104, Japan
[8] Shizuoka Canc Ctr, Dept Colon & Rectal Surg, Shizuoka, Japan
[9] Yokohama City Univ, Med Ctr, Yokohama, Kanagawa 232, Japan
[10] Toho Univ, Ohashi Hosp, Tokyo, Japan
[11] Keio Univ, Sch Med, Dept Surg, Tokyo 160, Japan
[12] Oita Univ, Fac Med, Oita 87011, Japan
[13] Natl Canc Ctr, Tokyo, Japan