Jin Yonezawa

Magnifying endoscopy with narrow-band imaging achieves superior accuracy in the differential diagnosis of superficial gastric lesions identified with white-light endoscopy: a prospective study

BACKGROUND Conventional, white-light imaging endoscopy (WLE) results in a significant number of misdiagnoses in early gastric cancer. Magnifying endoscopy combined with narrow-band imaging (ME-NBI) is more accurate in the diagnosis of gastric cancer when the diagnostic triad of the disappearance of fine mucosal structure, microvascular dilation, and heterogeneity is used. OBJECTIVE The aim of the present study was to evaluate the superiority of ME-NBI in the differential diagnosis of superficial gastric lesions identified with conventional WLE. DESIGN Prospective, comparative study. SETTING Single academic center. PATIENTS This study involved patients who underwent WLE and ME-NBI for surveying synchronous or metachronous cancers because they had a high risk of gastric cancer. INTERVENTION Patients with superficial gastric lesions that were diagnosed by WLE as cancer or non-cancer with a slight suspicion of cancer were prospectively enrolled in the study. ME-NBI was used to further characterize lesions picked up with WLE. MAIN OUTCOME MEASUREMENTS Sensitivity and specificity for the diagnosis of gastric cancer, with pathology as the criterion standard. RESULTS A total of 201 lesions (mean diameter [+/- SD] 7.0 +/- 4.0 mm) from 111 patients (98 men, 13 women; mean age 66.3 years) were evaluated. Fourteen of the 201 lesions were pathologically proven as gastric cancer; the others were noncancerous lesions. The sensitivity and specificity for ME-NBI diagnosis with the use of the triad (92.9% and 94.7%, respectively) were significantly better than for WLE (42.9% and 61.0%, respectively; P < .0001). LIMITATIONS Single center and a highly selected population at high risk for gastric cancer. CONCLUSION ME-NBI achieved superior accuracy in the differential diagnosis of superficial gastric lesions identified with WLE. Thus, ME-NBI may increase the diagnostic value of endoscopy in a population at high risk of gastric cancer.

CpG Island Hypermethylation of Tumor-Suppressor Genes in H. pylori-Infected Non-Neoplastic Gastric Mucosa Is Linked with Gastric Cancer Risk

Background and aim:  Gastric carcinogenesis involves CpG island hypermethylation (CIHM) of tumor‐suppressor genes. Although the CIHM of these genes occurs in non‐neoplastic gastric cells, it is unclear whether this epigenetic alteration is linked with aging and/or gastric cancer risk. We investigated this linkage in noncancerous gastric mucosa infected with H. pylori.

Trimodal imaging endoscopy may improve diagnostic accuracy of early gastric neoplasia: a feasibility study

BACKGROUND A considerable number of superficial gastric neoplasias are overlooked with conventional white light imaging (WLI) endoscopy. OBJECTIVE The aim was to investigate the diagnostic potential of trimodal imaging endoscopy (TME), which combines WLI, autofluorescence imaging (AFI), and narrow-band imaging (NBI), for superficial gastric neoplasia. DESIGN Feasibility study. SETTING Single academic center. PATIENTS Sixty-two patients with or without gastric neoplasia. INTERVENTION Each patient serially assessed with WLI, AFI, and magnifying endoscopy with NBI (ME-NBI) by an endoscopist blinded for clinical information. ME-NBI over WLI and AFI was designated as TME. Histopathology of biopsy and ESD specimens was evaluated and used as the gold standard. MAIN OUTCOME MEASUREMENTS Sensitivity and specificity of endoscopic diagnosis of pathology-proven neoplasia by per-patient and per-lesion analyses. RESULTS The study included 47 pathology-proven neoplasias and 44 pathology-proven nonneoplasias that were detected as neoplasias with any of the modalities. By a per-lesion analysis, the sensitivity of TME (89.4%) was higher than that of WLI (76.6%) and AFI (68.1%). The specificity of TME (98.0%) was higher than that of WLI (84.3%) and AFI (23.5%). By a per-patient analysis, the sensitivity of TME (90.9%) was higher than that of WLI (75%) and AFI (68.2%). The specificity of TME (100%) was higher than that of WLI (72.2%) and AFI (44.4%). LIMITATIONS Case-enriched population at a single center. CONCLUSIONS Higher diagnostic accuracy of TME over conventional WLI indicates the feasibility of TME for the efficacious diagnosis of early gastric neoplasia.

Ultrathin endoscopy versus high-resolution endoscopy for diagnosing superficial gastric neoplasia

BACKGROUND Ultrathin endoscopy (UTE) is an acceptable and cost-effective alternative to EGD with the patient under sedation, although the diagnostic accuracy of UTE is not well established. OBJECTIVE To compare the diagnostic accuracy of UTE and high-resolution endoscopy (HRE) for superficial gastric neoplasia. DESIGN Prospective comparative study. SETTING Academic center. PATIENTS AND INTERVENTIONS Patients with or without superficial gastric neoplasia underwent peroral UTE and HRE, back-to-back in a random order while under standard sedation. The procedures were performed by 2 endoscopists who were blinded to the clinical information. MAIN OUTCOME MEASUREMENTS The rate of missed lesions and misdiagnosis, sensitivity, and specificity for the diagnosis of gastric neoplasia when using pathology as the reference standard. RESULTS In total, 126 lesions (41 superficial gastric neoplasias, 85 nonneoplastic lesions) were recorded in 57 enrolled patients. For the diagnosis of gastric neoplasia, the sensitivity of UTE (58.5%) was significantly (P = .021) lower than that of HRE (78%), and the specificity of UTE (91.8%) was significantly (P = .014) lower than that of HRE (100%). The rate of missed lesions and misdiagnosis of gastric neoplasias when using UTE (41.5%) was significantly (P > .001) higher than that of HRE (22.0%). The corresponding rate of neoplasias at the proximal portion (fornix and corpus) when using UTE (29%) was significantly (P = .002) higher than that of HRE (7.2%), although the rates of neoplasias at the distal portion (angulus and antrum) were comparable for UTE and HRE. LIMITATION Small sample numbers in an enriched population. CONCLUSIONS The diagnostic accuracy of UTE is significantly lower than that of HRE for superficial gastric neoplasia, and this difference is particularly striking for neoplasias in the proximal stomach. For UTE to be used as an alternative modality, improvements in optical quality and the incorporation of additional procedures, including close-range observations and chromoendoscopy, are required to enhance visualization.

CONTACT ULTRA‐HIGH MAGNIFYING ENDOSCOPY CAN DIFFERENTIATE SQUAMOUS CELL CARCINOMA FROM NON‐CANCEROUS SQUAMOUS CELLS IN THE ESOPHAGUS: TWO CASES OF SUPERFICIAL ESOPHAGEAL CARCINOMA

Endocytoscopy, a type of contact ultra‐high magnifying endoscopy, enables in vivo observation of cells in the gastrointestinal tract. To test its clinical relevance, endocytoscopy was conducted on ex vivo specimens from two cases of superficial esophageal carcinoma that were resected by endoscopic mucosal resection (EMR). Using a catheter‐type system with ×450 magnification, endocytoscopic observation was performed on small areas of cancerous and non‐cancerous squamous cells, which were subsequently retrieved for pathological examination on horizontal sections. In both cases, endocytoscopy identified non‐cancerous areas as cells with sparsely distributed round nuclei and a low nucleus‐cytoplasm (NC) ratio, which correlated well with histological sections. Similarly, the endocytoscopy correlated well with histological sections of cancerous areas and identified cells with densely distributed irregular nuclei with a high NC ratio. In conclusion, the high correlation between histological and endocytoscopic identification of cancerous and non‐cancerous lesions may enable endocytoscopic diagnosis that is of comparable accuracy to the current pathological methodology. A prospective in vivo study is required to confirm the evidence.