Tomoki Shimizu
Japanese Foundation for Cancer Research
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Featured researches published by Tomoki Shimizu.
Digestive Endoscopy | 2013
Masami Omae; Junko Fujisaki; Tomoki Shimizu; Masahiro Igarashi; Noriko Yamamoto
It has been described that most cases of Barretts esophageal adenocarcinoma in Japan are cases of Barretts esophageal adenocarcinoma on a background of short‐segment Barretts esophagus, frequently occurring rostrad to Barretts epithelium, adjacent to the squamous epithelium of the right wall of the esophagogastric junction. Barretts esophageal adenocarcinoma may spread below the squamous epithelium when the tumor is situated adjacent to the squamocolumnar junction, so that it is usually difficult to diagnose its presence and extent by conventional endoscopy alone. We have noted that the spread of Barretts esophageal adenocarcinoma below the squamous epithelium is recognizable as annular vascular formations (AVF) by magnifying endoscopy with narrow‐band imaging (ME‐NBI), and have verified it by 3‐D stereo‐reconstruction using serial sections from a specimen of the same lesion. When horizontalcross‐sections of the tissue were viewed from the surface, AVF emerged at a depth of approximately 100 μm from the surface and disappeared at a depth of approximately 300 μm. Therefore, it would be presumed to be difficult to visualize the characteristic structural features by ME‐NBI if the carcinomatous glandular ducts were situated deeper than approximately 300 μm underneath a thick layer of squamous epithelium. Thickness of the overlying squamous epithelium may be a limiting factor for whether or not the characteristic structural features can be detected.
Endoscopy International Open | 2016
Masami Omae; Junko Fujisaki; Tomoki Shimizu; Yusuke Horiuchi; Akiyoshi Ishiyama; Toshiyuki Yoshio; Toshiaki Hirasawa; Yorimasa Yamamoto; Tomohiro Tsuchida; Masahiro Igarashi; Yasuyuki Seto
Background: Superficial Barrett’s esophageal adenocarcinoma (s-BEA) in Barrett’s esophagus frequently occurs in the right wall of the esophagus. Our aim was to examine the correlation between the location of s-BEA and the direction of acid and non-acid reflux in patients with Barrett’s esophagus. Patients and methods: We performed 24-h pH monitoring in 33 s-BEA patients using a pH catheter with eight sensors. One sensor was located at the 6 o’clock position in the lower esophagus and sensors 1 – 8 were arranged counterclockwise at the same level. The catheter was positioned at the same level as the s-BEA. We measured the maximal total duration of acid (MTD-A) and non-acid (MTD-NA) reflux. When the direction of MTD-A and MTD-NA coincided with the location of the s-BEA, the case was defined as coincidental and we calculated the rate of coincidence, and the probability of the rate of coincidence was estimated with 95 % confidence intervals (95 %CI). Results: Among the 33 cases of s-BEA examined, the rate of coincidence of both MTD-A and MTD-NA was 24/33 (72.7 %) (95 %CI 0.54 – 0.87). The rate of coincidence of either MTD-A or MTD-NA was 30/33 (90.9 %) (95 %CI 0.76 – 0.98). Conclusions: Our study revealed that the location of s-BEA mostly corresponds to the direction of MTD-A or MTD-NA. Accurate observation of the distribution of acid or non-acid reflux by pH monitoring would aid early detection of s-BEA by endoscopy.
Digestion | 2018
Tomoki Shimizu; Junko Fujisaki; Masami Omae; Akira Yamasaki; Yusuke Horiuchi; Akiyoshi Ishiyama; Toshiyuki Yoshio; Toshiaki Hirasawa; Yorimasa Yamamoto; Tomohiro Tsuchida
Background: In recent years, effective outcomes of endoscopic submucosal dissection (ESD) for esophagogastric junction cancer including short-segment Barrett’s esophagus (SSBE) cancer have been reported. However, the efficacy of ESD for long-segment Barrett’s esophagus (LSBE) cancer is unknown. Aim: To clarify the treatment outcomes of ESD for LSBE cancer versus SSBE cancer. Methods: A total of 86 patients with 91 superficial Barrett’s esophageal adenocarcinomas who underwent ESD were enrolled; of these, 68 had underlying SSBE and 18 had LSBE. Procedure outcomes and prognosis were compared. Results: There was no significant difference in age and tumor diameter among patients. The only complication observed was stricture, but it was not significant (2 vs. 9%). No significant difference was observed in the negative horizontal margin rates (94.1 vs. 95.7%), R0 resection rates (83.8 vs. 82.6%), curative resection rates (72.1 vs. 73.9%), and noncurative factors. Both LSBE and SSBE cancer showed favorable 3-year overall survival rates (95.0 vs. 94.4%) in the median observation period of 28.5 months. Conclusions: ESD for LSBE cancer achieved procedure outcomes and short-term prognosis comparable to SSBE. ESD has the potential to be an effective therapeutic option for esophageal neoplasms in patients with LSBE.
Journal of Gastroenterology and Hepatology | 2017
Nobuyuki Matsuhashi; Eiji Sakai; Ken Ohata; Norihisa Ishimura; Fujisaki Junko; Tomoki Shimizu; Katsunori Iijima; Tomoyuki Koike; Takao Endo; Takefumi Kikuchi; Tatsuya Inayoshi; Yuji Amano; Takahisa Furuta; Ken Haruma; Yoshikazu Kinoshita
The incidence of esophageal adenocarcinoma (EAC) in cases with long‐segment Barretts esophagus (BE) has not been investigated in Japan. The aim of this study is to investigate the incidence of EAC in Japanese cases with long‐segment BE prospectively.
Esophagus | 2018
Kenichi Goda; Junko Fujisaki; Ryu Ishihara; Manabu Takeuchi; Akiko Takahashi; Yasuhiro Takaki; Dai Hirasawa; Kumiko Momma; Yuji Amano; Kazuyoshi Yagi; Hiroto Furuhashi; Tomoki Shimizu; Takashi Kanesaka; Satoru Hashimoto; Yoichiro Ono; Taku Yamagata; Junko Fujiwara; Takane Azumi; Masako Nishikawa; Gen Watanabe; Yasuo Ohkura; Tsuneo Oyama
Aim and methodsThe Japan Esophageal Society created a working committee group consisting of 11 expert endoscopists and 2 pathologists with expertise in Barrett’s esophagus (BE) and esophageal adenocarcinoma. The group developed a consensus-based classification for the diagnosis of superficial BE-related neoplasms using magnifying endoscopy.ResultsThe classification has three characteristics: simplified, an easily understood classification by incorporating the diagnostic criteria for the early gastric cancer, including the white zone and demarcation line, and the presence of a modified flat pattern corresponding to non-dysplastic histology by adding novel diagnostic criteria. Magnifying endoscopic findings are composed of mucosal and vascular patterns, and are initially classified as “visible” or “invisible.” Morphologic features were evaluated for “visible” patterns, and were subsequently rated as “regular” or “irregular,” and the histology, non-dysplastic or dysplastic, was predicted.ConclusionWe introduce the process and outline of the magnifying endoscopic classification.
Gastric Cancer | 2016
Yusuke Horiuchi; Junko Fujisaki; Noriko Yamamoto; Tomoki Shimizu; Yuji Miyamoto; Hideomi Tomida; Masami Omae; Akiyoshi Ishiyama; Toshiyuki Yoshio; Toshiaki Hirasawa; Yorimasa Yamamoto; Tomohiro Tsuchida; Masahiro Igarashi; Hiroshi Takahashi
Gastric Cancer | 2016
Yusuke Horiuchi; Junko Fujisaki; Noriko Yamamoto; Tomoki Shimizu; Yuji Miyamoto; Hideomi Tomida; Chika Taniguchi; Kenjiro Morishige; Masami Omae; Akiyoshi Ishiyama; Toshiyuki Yoshio; Toshiaki Hirasawa; Yorimasa Yamamoto; Tomohiro Tsuchida; Masahiro Igarashi; Toshifusa Nakajima; Hiroshi Takahashi
Surgical Endoscopy and Other Interventional Techniques | 2017
Yusuke Horiuchi; Junko Fujisaki; Noriko Yamamoto; Tomoki Shimizu; Masami Omae; Akiyoshi Ishiyama; Toshiyuki Yoshio; Toshiaki Hirasawa; Yorimasa Yamamoto; Tomohiro Tsuchida; Masahiro Igarashi; Hiroshi Takahashi
Gastric Cancer | 2017
Hiroki Osumi; Junko Fujisaki; Masami Omae; Tomoki Shimizu; Toshiyuki Yoshio; Akiyoshi Ishiyama; Toshiaki Hirasawa; Tomohiro Tsuchida; Yorimasa Yamamoto; Hiroshi Kawachi; Noriko Yamamoto; Masahiro Igarashi
Clinical Journal of Gastroenterology | 2013
Yusuke Horiuchi; Junko Fujisaki; Tomoki Shimizu; Hirotaka Ishikawa; Yasumasa Matsuo; Natsuko Yoshizawa; Takanori Suganuma; Kiyohisa Dan; Masami Omae; Akiyoshi Ishiyama; Toshiaki Hirasawa; Yorimasa Yamamoto; Tomohiro Tsuchida; Etsuo Hoshino; Masahiro Igarashi; Naoki Hiki; Toshiharu Yamaguchi; Toshifusa Nakajima; Hiroshi Takahashi