Enhanced Magnifying Endoscopy for Diagnosis of Early Gastric Cancer

Patients who received surveillance endoscopy for EGC using a zoom endoscope were eligible for inclusion. WLE without magnification was performed first in eligible patients. Based on an assessment of the shape (such as flat, depressed or elevated) and color (pale or reddened), small focal gastric lesions were identified and included for evaluation by experienced endoscopists. When such a lesion was detected during non-magnifying observation with WLE, the mode was then changed to ME-NBI for observation of microvascular pattern and ME-AIM for observation of microsurface pattern subsequently. All endoscopic images of the whole procedure were recorded in digital filing system for later evaluation. To avoid possible selection bias and to maintain the quality of the study, all images of each endoscopic modality (including WLE, ME-NBI, ME-AIM), which were arranged randomly on one slide and displayed independently of the images of other endoscopic modality, were evaluated by 4 skilled endoscopists, who were not access to the clinical and pathological data. The general consensus was established for an assessment of each lesion. Two forceps biopsy specimens were taken from each lesion and pathological diagnosis were used as the criterion standard for cancer diagnosis.

Inclusion criteria

• Patients, in which small focal gastric lesions were identified with conventional WLE, were enrolled in this study. Before being enrolled, all patients provided written informed consent.

Exclusion criteria

• Patients who cannot undergo gastroscopies due to unsuitable conditions
• Referred patients with a history of having being diagnosed as gastric cancer
• Patients with a personal history of gastric surgery
• Patients who cannot provide informed consent
• Patients with advanced gastric cancer