[1] Natl Canc Ctr Hosp East, Dept Head & Neck Surg, Kashiwa, Chiba, Japan
[2] Iwate Med Univ, Dept Otolaryngol, Morioka, Iwate 020, Japan
[3] Iwate Med Univ, Dept Head & Neck Surg, Morioka, Iwate 020, Japan
[4] Tokyo Med & Dent Univ, Dept Head & Neck Surg, Tokyo, Japan
[5] Kitasato Univ, Dept Gastroenterol, Sagamihara, Kanagawa 228, Japan
[6] Natl Canc Ctr Hosp East, Dept Digest Endoscopy, Kashiwa, Chiba, Japan
[7] Natl Canc Ctr, Gastrointestinal Endoscopy Div, Dept Endoscopy, Tokyo, Japan
[8] Hokkaido Univ, Dept Gastroenterol & Hepatol, Sapporo, Hokkaido, Japan
[9] Ishikawa Prefectural Cent Hosp, Dept Gastroenterol, Kanazawa, Ishikawa, Japan
[10] Tohoku Univ, Dept Gastroenterol, Sendai, Miyagi 980, Japan
[11] Shizuoka Canc Ctr, Dept Endoscopy, Nagaizumi, Shizuoka, Japan
[12] Osaka Natl Hosp, Dept Surg, Osaka, Japan
[13] Okayama Univ, Dept Gastroenterol, Okayama 7008530, Japan
[14] Kanagawa Canc Ctr, Dept Gastroenterol, Yokohama, Kanagawa 2410815, Japan
[15] Keio Univ, Dept Surg, Tokyo, Japan
[16] Shizuoka Canc Ctr, Div Diagnost Pathol, Nagaizumi, Shizuoka, Japan
[17] Natl Canc Ctr Hosp East, Dept Pathol & Clin Labs, Kashiwa, Chiba, Japan
[18] Kyoto Prefectural Univ Med, Kyoto, Japan
[19] Dept Mol Targeting Canc Prevent, Kyoto, Japan
[20] Natl Inst Publ Hlth, Dept Hlth Promot, Wako, Saitama 3510197, Japan
[21] Natl Hosp Org Kurihama Med & Addict Ctr, Clin Res Unit, Yokosuka, Kanagawa, Japan
[22] Kyoto Univ, Dept Therapeut Oncol, Kyoto, Japan