Methods
Patients
This retrospective study was performed in the Department of Gastroenterology, Dalian Central hospital. During January 2008 to January 2011, a total of 14389 patients underwent endoscopic examination, and 526 lesions were detected. Among them, 122 patients were diagnosed as early gastric cancer or precancerous gastric lesions by the pathologic results, and were enrolled in this retrospective study. The ages of the122 patients (83 males and 39 females) ranged from 16 to 94 years with a mean age of 63.5 ± 14.1 years. Early gastric cancer was defined as cancer confined to the mucosa or submucosa regardless of lymph node metastasis. In our study, precancerous lesions referred to high grade intraepithelial neoplasia, which included intraepithelial carcinoma and severe dysplasia according to the Vienna classification of gastrointestinal epithelial neoplasms. All the lesions were confirmed by pathologic diagnosis of endoscopic resection or post-surgery tissue. Exclusion criteria were pre-existing or advanced gastric cancer, recent upper gastrointestinal bleeding or coagulation disorders, and severe comorbidities that may affect tolerance to upper endoscopy. The presenting manifestations were abdominal pain in 88 cases (72.1%), distension in 52 cases (42.6%), heartburn in 60 cases (49.2%), belching in 28 cases (23.0%), acid regurgitation in 32 cases (26.2%), and nausea in 29 cases (23.8%).
Procedures
The patients were first given careful observation in order to identify any abnormalities of the surface or the color with conventional endoscopy. After detecting lesions, magnifying chromoendoscopy and NBI magnifying endoscopy examination were followed on the same day or on another day. The morphology, pit pattern and blood capillary form of lesions were observed and recorded to determine that the lesion was malignant or benign (Figure 1). Then, biopsies were taken and studied by the same expert pathologist. The image quality was scored by two other endoscopists during the examination. Pathological diagnosis was regarded as the gold standard, and was used to assess accuracy of endoscopic diagnosis. Once lesions were diagnosed as gastric cancer or precancerous lesions, patients were underwent endoscopic resection or surgery. This study was approved by the Medical Science's ethics committee of Dalian Central hospital, patients were informed of the possible risks and benefits of participation in the study, and written informed consent was obtained from all the patients or their relatives before their examination.
(Enlarge Image)
Figure 1.
Demonstration of gastric precancerous lesion with conventional endoscopy(A) and iodine staining pattern (B); Pit pattern of this precancerous lesion with magnifying chromoendoscopy (C) and Blood capillary form with magnifying NBI (D).
Instruments
The NBI main unit was an Olympus CV-260SL and the endoscope was an Olympus GIF-H260Z (80×) (Olympus Corporation, Japan); 1.2% iodine was used for staining (Micro-Tech, Nanjing, CO., LTD).
Image Evaluation
The image quality was scored as follow: 1 point: obscure; 2 points: clouding; 3 points: more clear; and 4 points: clear.
Statistical Analysis
Data analysis was performed using SPSS 10.0 software (Chicago, IL, USA). Analysis of variance (ANOVA) or Wilcoxon statistical methods were used to determine statistical significance. All measurements in this study were expressed as mean ± SD. P < 0.05 was considered statistically significant.