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Dive into the research topics where Hiroshi Kawachi is active.

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Featured researches published by Hiroshi Kawachi.


Human Pathology | 2017

Intramucosal colorectal carcinoma with invasion of the lamina propria: a study by the Japanese Society for Cancer of the Colon and Rectum

Motohiro Kojima; Hideyuki Shimazaki; Keiichi Iwaya; Takahiro Nakamura; Hiroshi Kawachi; Kazuhito Ichikawa; Shigeki Sekine; Shingo Ishiguro; Tadakazu Shimoda; Ryoji Kushima; Takashi Yao; Takahiro Fujimori; Kazuo Hase; Toshiaki Watanabe; Kenichi Sugihara; Gregory Y. Lauwers; Atsushi Ochiai

Cancer invasion of the lamina propria is an important pathological finding. However, the clinicopathologic features and diagnostic accuracy of intramucosal carcinoma assessment in colorectal carcinoma (CRC) are unknown. In this study, intramucosal CRCs were reviewed in institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum, and 32 cases with invasion of the lamina propria were identified. Next, a consensus meeting was held to select cases with a high consensus about the presence of invasion, which were reviewed by one Western pathologist for confirmation. In addition to clinicopathologic evaluation, concordance was assessed for diagnosis and histologic findings. During the consensus meeting, 3 cases were found to show ambiguous features such that it was unclear whether there was intramucosal or submucosal invasion, and 7 cases were judged to have invasion of the lamina propria by more than 75% of the pathologists. A poorly differentiated adenocarcinoma and a signet ring cell carcinoma were diagnosed unanimously. Concordance in diagnosis and detection of characteristics of invasion of the lamina propria proved to be only poor to fair. Single or small clusters of cells and atypical or complex glandular arrangements that are beyond normal mucosal architecture were detected more frequently in the 7 high-consensus tumors. Desmoplasia and marked inflammation were detected more often in cases characterized as ambiguous. Intramucosal CRCs with invasion of the lamina propria constituted 5.1% of the surgically resected high-grade intramucosal epithelial dysplastic/neoplastic lesions, and stromal infiltration of single or small clusters of cells is the best objective criterion of invasion.


Journal of Gastric Cancer | 2018

Gastric Adenocarcinoma of Fundic Gland Type with Aggressive Transformation and Lymph Node Metastasis: a Case Report

Yasuhiro Okumura; Manabu Takamatsu; Manabu Ohashi; Yorimasa Yamamoto; Noriko Yamamoto; Hiroshi Kawachi; Satoshi Ida; Koshi Kumagai; Souya Nunobe; Naoki Hiki; Takeshi Sano

A 55-year-old man visited our hospital for a detailed examination of a gastric submucosal tumor that was first detected 10 years prior. The tumor continued to grow and had developed a depressed area in its center. A histopathological examination of biopsy specimens revealed gastric adenocarcinoma of the fundic gland type (GA-FG). It was diagnosed as T2 based on the invasion depth as determined by white-light endoscopy and endoscopic ultrasonography. A total gastrectomy with lymphadenectomy was performed and a GA-FG in the mucosa and submucosa was confirmed histopathologically. However, there was a gradual transition to an infiltrative tubular adenocarcinoma with poorly differentiated components in the muscular and subserosal layers. Metastasis was identified in a dissected lymph node (LN). This is the first report of a GA-FG progressing to an aggressive cancer with LN metastasis. These findings modify our understanding of the pathophysiology of GA-FG.


Ejso | 2018

Endoscopic criteria to evaluate tumor response of rectal cancer to neoadjuvant chemoradiotherapy using magnifying chromoendoscopy

Akiko Chino; Tsuyoshi Konishi; Atsushi Ogura; Hiroshi Kawachi; Hiroki Osumi; Toshiyuki Yoshio; Teruhito Kishihara; Daisuke Ide; Shoichi Saito; Masahiro Igarashi; Takashi Akiyoshi; Masashi Ueno; Junko Fujisaki

BACKGROUND AND AIMS Precise endoscopic assessment of complete response to neoadjuvant chemoradiotherapy before surgery is important for optimizing surgical and non-surgical treatment. We prospectively evaluated the accuracy of the newly proposed endoscopic criteria to identify complete response, using magnifying chromoendoscopy. METHODS New endoscopic criteria were created to define endoscopic complete response, near complete response and incomplete response, using magnifying chromoendoscopy. The criteria contained notable endoscopic findings, including shape of the scar, state of the ulcer, finding of white moss, presence of residual protruded nodules, regenerated pits of the scar, presence of neoplastic pit patterns, and extension of rectal wall. Seventy-nine patients with rectal cancer who received neoadjuvant chemoradiotherapy were prospectively evaluated 1-3 days before resection. Diagnostic accuracy to identify pathological complete response and interobserver agreement among a supervising colonoscopist and two trainees were investigated. RESULTS Pathological complete response was obtained in 17 patients (21.5%). The diagnostic accuracy of endoscopic complete response was 85%, with a sensitivity of 47%, specificity of 97%, positive predictive value of 80% and negative predictive value of 77%. The kappa-value for interobserver agreement across 3 doctors was 0.57 (standard error, 0.74; 95% confidence interval, 0.39-0.76). CONCLUSION The newly proposed endoscopic criteria using magnifying chromoendoscopy achieved excellent diagnostic accuracy to determine good responders to neoadjuvant chemoradiotherapy in rectal cancer, with fair interobserver agreement. The criteria could be clinically useful to select patients for non-surgical management.


Esophagus | 2017

The importance of the concept and histological criteria of "intraepithelial squamous cell carcinoma" of the esophagus : in comparison between Western and Japanese criteria

Masayuki Itabashi; Anna Nasierowska-Guttmejer; Tadakazu Shimoda; Przemysław Majewski; Witold Rezner; Katarzyna Sikora; Ewa Śrutek; Katarzyna Stęplewska; Jarosław Swatek; Justyna Szumiło; Agnieszka Wierzchniewska-Ławska; Lech Wronecki; Ewa Zembala-Nożyńska; Tomio Arai; Masahiro Fujita; Hiroshi Kawachi; Masamitsu Unakami; Toshiro Kamoshida

BackgroundThere are differences in the histological diagnostic criteria for early stage gastrointestinal carcinoma between Western and Japanese pathologists. Western histological criteria of carcinoma are “presence of stromal invasion of neoplastic cells”, while Japanese criteria are “the degree of cytological and structural abnormality of neoplastic cells, regardless of stromal invasion”. The aim of the present study is to clarify and review the present status of the Western and Japanese histological criteria of early stage esophageal squamous cell carcinoma (SCC) and also to clarify their significance and accuracy.MethodsTwenty-nine Polish, German, and Japanese pathologists participated in this study. A total of 18 histological slides of biopsy, endoscopic submucosal dissection (ESD), and surgical resection of esophageal squamous lesions were diagnosed using a virtual slide system.ResultsMost of noninvasive (intraepithelial) carcinomas diagnosed by Japanese pathologists were diagnosed as high- or low-grade dysplasia (intraepithelial neoplasia) or reactive atypia by the majority of Polish and German pathologists. Diagnoses of not only high-grade dysplasia but also low-grade dysplasia or reactive lesion by Western criteria were given for many biopsy specimens of cases in which the corresponding ESD or surgical specimens showed definite stromal invasion.ConclusionThere still exist differences in the histological diagnostic criteria for early stage esophageal carcinoma between Western and Japanese pathologists. The Japanese diagnostic criteria could improve agreement of diagnoses between biopsy and resected specimens of esophageal SCC. Moreover, diagnostic approaches using Western criteria may cause delay in the early diagnosis and treatment of esophageal SCC.


Digestive Endoscopy | 2017

Anti‐Neutrophil Cytoplasmic Antibody‐Associated Vasculitis Resembling Esophageal Cancer

Takanori Kurogochi; Shinji Mine; Hiroshi Kawachi

Systemic vasculitis can present with a variety of symptoms and signs1, 2. Some cases may be confused with cancer3. We herein describe the case of esophagitis caused by vasculitis. A 79-year-old male with mild dysphagia who was suspected with esophageal cancer at a previous hospital was referred to our facility. Upper GI endoscopy, which was undergone at our hospital, revealed a circumferentially elevated lesion with ulceration (Fig. 1a). This article is protected by copyright. All rights reserved.


European Journal of Cancer | 2018

Pattern of programmed cell death-ligand 1 expression and CD8-positive T-cell infiltration before and after chemoradiotherapy in rectal cancer

Atsushi Ogura; Takashi Akiyoshi; Noriko Yamamoto; Hiroshi Kawachi; Yuichi Ishikawa; Seiichi Mori; Koji Oba; Masato Nagino; Yosuke Fukunaga; Masashi Ueno


Gastric Cancer | 2017

Clinicopathological features of Siewert type II adenocarcinoma: comparison of gastric cardia adenocarcinoma and Barrett’s esophageal adenocarcinoma following endoscopic submucosal dissection

Hiroki Osumi; Junko Fujisaki; Masami Omae; Tomoki Shimizu; Toshiyuki Yoshio; Akiyoshi Ishiyama; Toshiaki Hirasawa; Tomohiro Tsuchida; Yorimasa Yamamoto; Hiroshi Kawachi; Noriko Yamamoto; Masahiro Igarashi


Journal of Gastroenterology | 2018

Clinical impact of intratumoral HER2 heterogeneity on trastuzumab efficacy in patients with HER2-positive gastric cancer

Takeru Wakatsuki; Noriko Yamamoto; Takeshi Sano; Keisho Chin; Hiroshi Kawachi; Daisuke Takahari; Mariko Ogura; Takashi Ichimura; Izuma Nakayama; Hiroki Osumi; Tomohiro Matsushima; Mitsukuni Suenaga; Eiji Shinozaki; Naoki Hiki; Yuichi Ishikawa; Kensei Yamaguchi


ESGE Days 2018 accepted abstracts | 2018

GASTRIC ADENOCARCINOMA OF FUNDIC GLAND TYPE: CLINICOPATHOLOGICAL FEATURES DETERMINED BY RETROSPECTIVE ANALYSIS

S Shiroma; Toshiaki Hirasawa; M Takamatsu; Hiroshi Kawachi; Shoichi Yoshimizu; Yusuke Horiuchi; Akiyoshi Ishiyama; Toshiyuki Yoshio; Tomohiro Tsuchida; Junko Fujisaki


International Journal of Colorectal Disease | 2017

Does the depth of mesorectal invasion have prognostic significance in patients with ypT3 lower rectal cancer treated with preoperative chemoradiotherapy

Atsushi Ogura; Takashi Akiyoshi; Noriko Yamamoto; Hiroshi Kawachi; Yuichi Ishikawa; Hisashi Noma; Masato Nagino; Yosuke Fukunaga; Masashi Ueno

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Noriko Yamamoto

Japanese Foundation for Cancer Research

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Hiroki Osumi

Japanese Foundation for Cancer Research

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Junko Fujisaki

Japanese Foundation for Cancer Research

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Masahiro Igarashi

Japanese Foundation for Cancer Research

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Akiyoshi Ishiyama

Japanese Foundation for Cancer Research

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Atsushi Ogura

Japanese Foundation for Cancer Research

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Masashi Ueno

Japanese Foundation for Cancer Research

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Takashi Akiyoshi

Japanese Foundation for Cancer Research

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Tomohiro Tsuchida

Japanese Foundation for Cancer Research

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