Risk of metastatic recurrence after endoscopic resection for esophageal squamous cell carcinoma invading into the muscularis mucosa or submucosa: a multicenter retrospective study

Waku Hatta, Tomoyuki Koike, So Takahashi, Tomohiro Shimada, Takuto Hikichi, Yosuke Toya, Ippei Tanaka, Yusuke Onozato, Koichi Hamada, Daisuke Fukushi, Ko Watanabe, Shoichi Kayaba, Hirotaka Ito, Tatsuya Mikami, Tomoyuki Oikawa, Yasushi Takahashi, Yutaka Kondo, Tetsuro Yoshimura, Takeharu Shiroki, Ko Nagino, Norihiro Hanabata, Akira Funakubo, Dai Hirasawa, Tetsuya Ohira, Jun Nakamura, Takayuki Matsumoto, Tomohiro Nakamura, Naoki Nakaya, Katsunori Iijima, Shinsaku Fukuda, Atsushi Masamune, Tohoku GI Endoscopy Group