Yoshiro Kawahara

Magnifying narrowband imaging is more accurate than conventional white-light imaging in diagnosis of gastric mucosal cancer.

BACKGROUND & AIMS It is difficult to accurately diagnose patients with depressed gastric mucosal cancer based on conventional white-light imaging (C-WLI) endoscopy. We compared the real-time diagnostic yield of C-WLI for small, depressed gastric mucosal cancers with that of magnifying narrow-band imaging (M-NBI). METHODS We performed a multicenter, prospective, randomized, controlled trial of patients with undiagnosed depressed lesions ≤10 mm in diameter identified by esophagogastroduodenoscopy. Patients were randomly assigned to groups that were analyzed by C-WLI (n = 176) or M-NBI (n = 177) immediately after detection; the C-WLI group received M-NBI after C-WLI. We compared the diagnostic accuracy, sensitivity, and specificity between C-WLI and M-NBI and assessed the diagnostic yield of M-NBI conducted in conjunction with C-WLI. RESULTS Overall, 40 gastric cancers (20 in each group) were identified. The median diagnostic values for M-NBI and C-WLI were as follows: accuracy, 90.4% and 64.8%; sensitivity, 60.0% and 40.0%; and specificity, 94.3% and 67.9%, respectively. The accuracy and specificity of M-NBI were greater than those of C-WLI (P < .001); the difference in sensitivity was not significant (P = .34). The combination of M-NBI with C-WLI significantly enhanced performance compared with C-WLI alone; accuracy increased from (median) 64.8% to 96.6% (P < .001), sensitivity increased from 40.0% to 95.0% (P < .001), and specificity increased from 67.9% to 96.8% (P < .001). CONCLUSIONS M-NBI, in conjunction with C-WLI, identifies small, depressed gastric mucosal cancers with 96.6% accuracy, 95.0% sensitivity, and 96.8% specificity. These values are better than for C-WLI or M-NBI alone.

Risk factors associated with local recurrence of early gastric cancers after endoscopic submucosal dissection

BACKGROUND Although endoscopic submucosal dissection (ESD) is expected to reduce the local recurrence of gastric cancers, we still experience cases of recurrence after an ESD. OBJECTIVE To characterize clinical and pathologic features of cases with local recurrence of early gastric cancer after an ESD. DESIGN A prospective cohort study. SETTING AND PATIENTS A total of 306 patients with gastric cancers removed by ESD at Okayama University Hospital and Tsuyama Central Hospital between March 2001 and December 2005 were enrolled. INTERVENTION ESD. MAIN OUTCOME MEASUREMENT Local recurrence. RESULTS The incidence of a complete en bloc resection was 80.4% when pathologically evaluated. Within a median follow-up period of 26 months (12-64 months), a local recurrence was found in 7 cases, all of which had been declared incomplete resections. One patient underwent a second ESD, and the remaining 6 underwent a surgical resection. All removed lesions were mucosal cancers. No lymph-node metastases were found in patients with a surgical resection. There was a significant correlation between the incidence of an incomplete resection and that of a local recurrence (P < .0001). Among the clinical characteristics, tumor size (>30 mm vs <20 mm; odds ratio [OR] 16 mm [95% CI, 2.0-130 mm]) and tumor location (upper vs middle or lower; OR 7.6 [95% CI, 1.3-45]) were identified as factors that were significantly associated with the incidence of a local recurrence. LIMITATION Short follow-up duration. CONCLUSIONS The incidence of a local recurrence was strongly associated with that of an incomplete resection. The frequency of a local recurrence also showed significant correlations with the tumor size and location within the stomach.

Helicobacter pylori eradication reduced the incidence of gastric cancer, especially of the intestinal type

Although Helicobacter pylori infection is closely associated with gastric cancer development, follow‐up studies after H. pylori eradication are still scarce.

Narrow-Band Imaging Provides Reliable Screening for Esophageal Malignancy in Patients With Head and Neck Cancers

OBJECTIVES:The narrow-band imaging (NBI) system is a novel technology that enhances the visualization of microvasculature and mucosal patterns. The aim of this study was to assess the reliability of the NBI system for esophageal cancer screening in patients with head and neck cancers.METHODS:A total of 142 patients with head and neck squamous cell carcinoma (SCC) were examined by NBI endoscopy, followed by Lugol chromoendoscopy between April 2006 and June 2008 at the Okayama University Hospital, Okayama, Japan. Detection of SCC and high-grade intraepithelial neoplasia (HGIN) was conducted.RESULTS:The median age of the patients was 64 years (range: 29–86 years), and approximately three-fourths of all the patients were male. In total, 21 superficial lesions in 16 patients were detected by NBI endoscopy. Of these, 4 lesions were diagnosed histologically as SCC and 11 lesions as HGIN. An additional 22 Lugol-voiding lesions ≥5 mm were detected in 19 patients by Lugol chromoendoscopy. Although 1 of these lesions was diagnosed as HGIN, 21 lesions were diagnosed as low-grade intraepithelial neoplasia or lesions without atypical findings. The sensitivity of NBI endoscopy for detecting esophageal SCC and HGIN was 90.9% (95% confidence interval (CI), 58.7–99.8), specificity was 95.4% (95% CI, 90.3–98.3), and accuracy was 95.1% (95% CI, 90.1–98.0).CONCLUSIONS:NBI seems to be useful and reliable for screening for esophageal SCC in patients with head and neck cancers.

ROLE OF NARROW BAND IMAGING FOR DIAGNOSIS OF EARLY-STAGE ESOPHAGOGASTRIC CANCER: CURRENT CONSENSUS OF EXPERIENCED ENDOSCOPISTS IN ASIA-PACIFIC REGION

In Asian countries, squamous cell carcinoma is the most common type of esophageal cancer, and the incidence of gastric cancer remains have plateaued. To synthesize current information and to illustrate its clinical benefit of narrow band imaging (NBI) for diagnosis of superficial esophageal squamous carcinoma (SESCC) and early gastric cancer (EGC), a consensus conference was held by a panel of nine experts from Asian‐Pacific countries. The experts agreement suggested importance of interpretation of both vascular architecture and surface structure of the lesions and proper processor settings for endoscopic images. Zoom endoscopy was not regarded as absolutely necessary for detection of SESCC, but magnifying observation provided valuable information for characterization of detected lesions in the esophagus and the stomach. In general, NBI is useful for detection and characterization of SESCC, whereas it is beneficial mainly for characterization of EGC. Chromoendoscopy was found to be still worthwhile in certain situations, such as determination of the extent of SESCC by Lugols staining, or detection and delineation of EGC by indigo carmine. NBI could replace chromoendoscopy in routine examination because it is easy to use and adds much information to conventional WLI, but it cannot eliminate chromoendoscopy when we make a final diagnosis for treatment decision‐making. Consequently, the benefit of NBI or magnifying NBI is specific for the organ and the purpose of the examination, thus optimum indication and usage should be understood for maximum clinical benefit.

Antibodies to human gastric epithelial cells and heat shock protein 60 in Helicobacter pylori positive mucosa associated lymphoid tissue lymphoma.

BACKGROUND Development of gastric mucosa associated lymphoid tissue (MALT) lymphoma is thought to be closely associated with host immune reactions toHelicobacter pylori. AIM To investigate humoral immune responses in patients with MALT lymphoma to antigens shared by H pylori and human gastric epithelial cells. METHODS Sera were obtained from H pylori positive patients with MALT lymphoma (n = 11) or other gastroduodenal diseases (peptic ulcer, n = 40; non-ulcer dyspepsia, n = 20) and fromH pylori negative healthy control subjects (n = 10). Antibodies to HGC-27 human gastric epithelial cells and human recombinant heat shock protein (Hsp) 60 were examined using an enzyme linked immunosorbent assay (ELISA) and immunoblotting. RESULTS Antibody titres to HGC-27 cells were significantly elevated inH pylori positive patients with MALT lymphoma when compared with titres in patients with other gastroduodenal diseases and in healthy subjects. Immunoblotting of sera from patients with MALT lymphoma often detected a band with a molecular mass corresponding to Hsp60, and both ELISA and immunoblotting showed elevated antibody titres to the recombinant human Hsp60. Antigenic similarity between Hsp60 and H pylori HspB was documented by immunoblotting experiments. CONCLUSIONS Autoantibodies reactive with host gastric epithelial cells are often increased in MALT lymphoma, and Hsp60 is a major target antigen. Immune responses induced by immunological cross reactivity between H pylori HspB and human Hsp60 in gastric epithelium may be involved in the development of MALT lymphoma.

Endoscopic submucosal dissection in the colorectum: Present status and future prospects

Endoscopic submucosal dissection (ESD) can successfully resect early stage gastrointestinal tumors, but colorectal ESDs are not widely performed, even by Japanese endoscopists, because of several negative factors. Besides being considerably more difficult in terms of technical demands, colorectal ESDs involve a longer procedure time and have a higher complication rate compared to gastric ESDs. In addition, most colorectal lesions are adenomas or intramucosal cancers that despite their large size that can be curatively treated by endoscopic mucosal resection including piecemeal resection.

Lugol-Voiding Lesions Are an Important Risk Factor for a Second Primary Squamous Cell Carcinoma in Patients With Esosphageal Cancer or Head and Neck Cancer

OBJECTIVES:Lugol-voiding lesions (LVLs), detected by chromoendoscopy using iodine dye in patients with esophageal squamous cell carcinoma (EC) or head and neck squamous cell carcinoma (HNC), are associated with a second primary carcinoma in the other organ. We undertook a cross-sectional and retrospective cohort study to assess the risk for second primary carcinomas according to the severity of LVLs, on the basis of their number and size.METHODS:A total of 1,060 patients with only EC, only HNC, or both EC and HNC (EC+HNC) underwent esophageal endoscopic examination between January 1994 and January 2010. The patients were classified according to the number of LVLs in an endoscopic visual field and the size of the largest LVLs. Factors associated with the second primary EC or HNC were analyzed.RESULTS:Univariate analysis showed that a larger number and size of LVLs increased the risk for synchronous and early metachronous second primary cancer (P value for trend <0.0001). Multivariate analysis showed that a number of LVLs ≥20 (EC+HNC vs. only HNC, odds ratio (OR)=15.7; EC+HNC vs. only EC, 3.5) and a size ≥10 mm (EC+HNC vs. only HNC, OR=3.1; EC+HNC vs. only EC, 3.2) were independent risk factors for synchronous and early metachronous second primary cancer. A larger number of LVLs was a risk factor for metachronous EC and HNC, and a size ≥10 mm was a risk factor for late metachronous EC.CONCLUSIONS:The severity of LVLs in patients with HNC or EC closely correlated with a second primary carcinoma in the other organ. Patients with LVLs must be followed closely for development of a second primary carcinoma.

Novel chromoendoscopic method using an acetic acid-indigocarmine mixture for diagnostic accuracy in delineating the margin of early gastric cancers

Background and Aim:  Recent endoscopic imaging techniques for recognition of unclear lesions in the stomach (e.g. narrow band imaging, magnifying endoscopy) require special equipment and therefore are not commonly used. The aim of the present study was to estimate the accuracy of a new chromoendoscopic method using an acetic acid–indigo carmine mixture (AIM) in diagnosing early gastric cancers (EGC).

Detection of Helicobacter pylori associated antigen and heat shock protein 60 on follicular dendritic cells in the germinal centres of low grade B cell lymphoma of gastric mucosa associated lymphoid tissue (MALT)

AIMS: To investigate the localisation of Helicobacter pylori antigens and the expression of human heat shock proteins (HSP) in stomachs affected by MALT lymphoma. METHODS: Surgically resected stomachs from 24 patients with MALT lymphoma were immunostained with anti-H pylori rabbit antibodies (ORP-1 and ORP-2) and anti-human HSP60 mouse monoclonal antibodies (mAb) (LK-1 and LK-2). RESULTS: Follicular dendritic cells of germinal centres in the stomachs affected by MALT lymphoma were immunostained with anti-H pylori polyclonal antibodies and with anti-human HSP60 mAb, as were the epithelial cells. None of the lymph node samples reacted. CONCLUSIONS: Human HSP60, which cross reacts with anti-H pylori polyclonal antibodies, is often expressed on follicular dendritic cells in gastric MALT lymphoma tissues and may be aetiologically relevant to lymphomagenesis of MALT lymphoma.