Sano, Japan
Sano, Japan

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Hewett D.G.,Indiana University | Hewett D.G.,University of Queensland | Kaltenbach T.,Veterans Affairs Palo Alto Health Care System | Kaltenbach T.,Stanford University | And 7 more authors.
Gastroenterology | Year: 2012

BACKGROUND & AIMS: Almost all colorectal polyps ≤5 mm are benign, yet current practice requires costly pathologic analysis. We aimed to develop and evaluate the validity of a simple narrow-band imaging (NBI)-based classification system for differentiating hyperplastic from adenomatous polyps. METHODS: The study was conducted in 4 phases: (1) evaluation of accuracy and reliability of histologic prediction by NBI-experienced colonoscopists; (2) development of a classification based on color, vessels, and surface pattern criteria, using a modified Delphi method; (3) validation of the component criteria by people not experienced in endoscopy or NBI analysis (25 medical students, 19 gastroenterology fellows) using 118 high-definition colorectal polyp images of known histology; and (4) validation of the classification system by NBI-trained gastroenterology fellows, using still images. We performed a pilot evaluation during real-time colonoscopy. RESULTS: We developed a classification system for the endoscopic diagnosis of colorectal polyp histology and established its predictive validity. When all 3 criteria were used, the specificity ranged from 94.9% to 100% and the combined sensitivity ranged from 8.5% to 61.0%. The specificities of the individual criteria were lower although the sensitivities were higher. During realtime colonoscopy, endoscopists made diagnoses with high confidence for 75% of consecutive small colorectal polyps, with 89% accuracy, 98% sensitivity, and 95% negative predictive values. CONCLUSIONS: We developed and established the validity of an NBI classification system that can be used to diagnose colorectal polyps. In preliminary real-time evaluation, the system allowed endoscopic diagnoses of colorectal polyp histology. © 2012 AGA Institute.


Hayashi N.,Hiroshima University | Tanaka S.,Hiroshima University | Hewett D.G.,University of Queensland | Kaltenbach T.R.,Veterans Affairs Palo Alto Health Care System | And 5 more authors.
Gastrointestinal Endoscopy | Year: 2013

Background: A simple endoscopic classification to accurately predict deep submucosal invasive (SM-d) carcinoma would be clinically useful. Objective: To develop and assess the validity of the NBI international colorectal endoscopic (NICE) classification for the characterization of SM-d carcinoma. Design: The study was conducted in 4 phases: (1) evaluation of endoscopic differentiation by NBI-experienced colonoscopists; (2) extension of the NICE classification to incorporate SM-d (type 3) by using a modified Delphi method; (3) prospective validation of the individual criteria by inexperienced participants, by using high-definition still images without magnification of known histology; and (4) prospective validation of the individual criteria and overall classification by inexperienced participants after training. Setting: Japanese academic unit. Main Outcome Measurements: Performance characteristics of the NICE criteria (phase 3) and overall classification (phase 4) for SM-d carcinoma; sensitivity, specificity, predictive values, and accuracy. Results: We expanded the NICE classification for the endoscopic diagnosis of SM-d carcinoma (type 3) and established the predictive validity of its individual components. The negative predictive values of the individual criteria for diagnosis of SM-d carcinoma were 76.2% (color), 88.5% (vessels), and 79.1% (surface pattern). When any 1 of the 3 SM-d criteria was present, the sensitivity was 94.9%, and the negative predictive value was 95.9%. The overall sensitivity and negative predictive value of a global, high-confidence prediction of SM-d carcinoma was 92%. Interobserver agreement for an overall SM-d carcinoma prediction was substantial (kappa 0.70). Limitations: Single Japanese center, use of still images without prospective clinical evaluation. Conclusion: The NICE classification is a valid tool for predicting SM-d carcinomas in colorectal tumors. Copyright © 2013 by the American Society for Gastrointestinal Endoscopy.


Uraoka T.,Okayama University | Saito Y.,National Cancer Center Hospital | Ikematsu H.,National Cancer Center East Hospital | Yamamoto K.,Okayama University of Science | Sano Y.,Sano Hospital
Digestive Endoscopy | Year: 2011

Narrow-band imaging enhances visualization of the mucosal surface structure and vascular network and helps to increase the visibility of neoplasia by improving contrast. Sano and his colleagues first reported its efficacy for endoscopic use in the gastrointestinal tract and later proposed a sequential classification of the mucosal vascular network patterns according to histopathological categories. Sano's 'capillary pattern classification' was established to facilitate diagnosis of early colorectal lesions on a step-by-step basis. This review focuses on the utility and effectiveness of Sano's capillary pattern classification when examining early colorectal lesions using narrow-band imaging. © 2011 The Authors Digestive Endoscopy © 2011 Japan Gastroenterological Endoscopy Society.


Ikematsu H.,National Cancer Center Hospital East | Saito Y.,National Cancer Center Hospital | Tanaka S.,Hiroshima University | Uraoka T.,Okayama University | And 7 more authors.
Journal of Gastroenterology | Year: 2012

Background: Previous studies have yielded conflicting results on the adenoma detection rate with narrow band imaging (NBI) compared with white light imaging (WLI). To overcome the confounding factors of these studies, we aimed to evaluate the colonic adenoma detection rate with primary NBI versus that with primary WLI by using consistent NBI system, endoscope, and imaging settings, and experienced colonoscopists. Methods: In this multicenter prospective trial, 813 patients were randomized to undergo high-definition, tandem colonoscopy in the right colon with either NBI followed by WLI (NBI-WLI group) or WLI followed by NBI (WLI-NBI group). The NBI settings were fixed at surface structure enhancement level A-5 and adaptive index of hemoglobin color enhancement level 3. All detected polyps were resected or biopsied for histopathological analysis. The primary and secondary outcome measures were the adenoma detection rates and miss rates, respectively, with primary imaging. Results: The NBI-WLI and WLI-NBI groups comprised 389 and 393 patients, respectively, who met the inclusion criteria. The groups did not differ significantly in age, gender, institution, indication for colonoscopy, bowel preparation, or observation time. The adenoma detection rates of primary NBI and WLI were 42.3 and 42.5 %, respectively [difference not significant (NS)]. The adenoma miss rate was significantly less with primary NBI than with primary WLI (21.3 vs. 27.8 %; p = 0.03). Conclusions: NBI does not improve the adenoma detection rate during primary colonoscopy; however, it has a lower miss rate for adenoma lesions in the proximal colon than WLI. © 2012 Springer.


Matsuda T.,National Cancer Center Hospital | Saito Y.,National Cancer Center Hospital | Hotta K.,TF Clinic | Sano Y.,Saku Central Hospital | Fujii T.,Sano Hospital
Digestive Endoscopy | Year: 2010

Flat and depressed (nonpolypoid) colorectal lesions have been described for over two decades by Japanese investigators. These neoplastic lesions are typically smaller than polypoid ones and can be more difficult to identify during screening colonoscopy. In particular, depressed type colorectal lesions are usually small in size, with a number of studies showing them to be at greater risk for developing high-grade dysplasia or submucosal invasive cancer. It has also been suggested that they may follow a different carcinogenic pathway to flat elevated or protruding adenomas. This paper summarizes recent data of nonpolypoid colorectal neoplasms from Western and Asian countries. © 2010 Japan Gastroenterological Endoscopy Society.


Oba S.,Hiroshima University | Tanaka S.,Hiroshima University | Sano Y.,Sano Hospital | Oka S.,Hiroshima University | Chayama K.,Hiroshima University
Digestion | Year: 2011

The narrow-band imaging system can be used to examine the microvascular architecture and surface pattern on the mucosal surface with high sensitivity. The clinical significance of NBI observation is summarized as follows: (1) differential diagnosis of hyperplasia, adenoma, and carcinoma; (2) diagnosis according to the presence of a surface pattern as an alternative to magnifying endoscopic observation with dye spraying, and (3) determination of the invasion depth of an early colorectal carcinoma. However, at present, many NBI magnifying observation classifications for colorectal tumor exist in Japan. To internationally standardize the NBI observation criteria, a simple classification system is required. On the basis of these backgrounds, an international cooperative group (Colon Tumor NBI Interest Group - CTNIG) has developed a simple category classification (NICE classification: NBI International Colorectal Endoscopic Classification) which classifies NBI findings into types 1-3. Copyright © 2011 S. Karger AG, Basel.


At present, there are many narrow band imaging (NBI) magnifying observation classifications for colorectal tumor in Japan. To internationally standardize the NBI observation criteria, a simple classification system is required. When a colorectal tumor is closely observed using the recent high-resolution videocolonoscope, a pit-like pattern on the tumor can be observed to a certain degree without magnification. In the symposium we could have a consensus that we will name the pit-like pattern as 'surface pattern.' Using the NBI system, the microvessels on the tumor surface can also be recognized to a certain degree. When the NBI system is used, the structure is emphasized, and consequently, the surface pattern can be recognized easily. Recently, an international cooperative group was formed and consists of members from Japan, the USA and Europe, which is named as the Colon Tumor NBI Interest Group. This group has developed a simple category classification (NBI international colorectal endoscopic [NICE] classification), which classifies colorectal tumors into types 1-3 even by closely observing colorectal tumors using a high-resolution videocolonoscope (Validation study is now ongoing by Colon Tumor NBI Interest Group.). The key advantage of this is simplification of the NBI classification. Although the magnifying observation is the best for getting detailed NBI findings, both close observation and magnifying observation using the NICE classification might give almost similar results. Of course the NICE classification can be used more precisely with magnification. In this report we also refer the issues on NBI magnification, which should be solved as early as possible. © 2011 The Authors Digestive Endoscopy © 2011 Japan Gastroenterological Endoscopy Society.


Kobayashi N.,Tochigi Cancer Center | Matsuda T.,National Cancer Center Hospital | Sano Y.,Sano Hospital
Gastrointestinal Endoscopy Clinics of North America | Year: 2010

Despite their importance, little is known about the natural history of non-polypoid colorectal neoplasms (NP-CRN). This article will summarize the available data to gain some estimates of the natural history of NP-CRN. © 2010 Elsevier Inc.


Takizawa K.,Shizuoka Cancer Center | Ono H.,Shizuoka Cancer Center | Kakushima N.,Shizuoka Cancer Center | Tanaka M.,Shizuoka Cancer Center | And 7 more authors.
Gastric Cancer | Year: 2013

Background: The behavior of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) is incompletely understood. This study aimed to clarify the clinicopathological features of EGC with mixed-type histology in relation to lymph node (LN) metastasis. Methods: Clinicopathological data from 410 patients who underwent surgical resection for intramucosal EGC were reviewed. Lesions were classified into four types according to the proportion of differentiated and undifferentiated components at histopathology: pure differentiated (PD) type, mixed predominantly differentiated (MD) type, mixed predominantly undifferentiated (MU) type, and pure undifferentiated (PU) type. We examined the clinicopathological differences between PD and MD, and between PU and MU, and the rate of LN metastasis according to tumor size and ulceration. Results: Moderately differentiated adenocarcinoma was the primary component in MD relative to PD (90.7 vs. 46.1 %). Signet ring cell carcinoma was the main component in PU relative to MU (81.5 vs. 33.3 %). LN metastasis was more common in MU than PU (19.0 vs. 6.0 %). For intramucosal tumors larger than 20 mm without lymphovascular invasion and without ulceration, the rate of LN metastasis was 0 % for MD and 24 % for MU. For intramucosal lesions less than 30 mm with ulceration but without lymphovascular invasion, the rate of LN metastasis was 0 % for MD and 20 % for MU. Conclusions: Histologically mixed-type EGC with a predominantly undifferentiated component should be managed as an undifferentiated-type tumor. Further investigation is required to determine whether mixed-type EGC with a predominantly differentiated component could be managed the same way as a differentiated-type EGC. © 2012 The International Gastric Cancer Association and The Japanese Gastric Cancer Association.


Sano Y.,Sano Hospital | Iwadate M.,Sano Hospital
Gastrointestinal Endoscopy Clinics of North America | Year: 2010

The importance and prevalence of the superficial lesions in the colon and rectum caught worldwide public attention in 2008 when Soetikno and colleagues reported the prevalence of non-polypoid (flat and depressed) colorectal neoplasms in asymptomatic and symptomatic adults in North America and the public media disseminated their findings. The publication put to rest the question of whether or not the flat and depressed colorectal neoplasms exist in Western countries; flat and depressed colorectal neoplasms can be found throughout the world. In this article, the author highlights the importance of the macroscopic classification of the colorectal neoplasm and emphasizes the distinction between so-called flat lesions (IIa and IIb) and 0-IIc (superficial depressed) neoplastic colorectal lesions. © 2010 Elsevier Inc.

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