Optical biopsy strategy for the assessment of atrophic gastritis, intestinal metaplasia, and dysplasia.

BACKGROUND AND AIMS: The pathogenesis of gastric cancer involves premalignant changes of the gastric mucosa. An accurate estimation of the topography and severity of these lesions represents an important step in detecting premalignant lesions, thereby classifying patients into low or high risk of developing gastric cancer. We prospectively analyzed the diagnostic performance of narrow-band imaging with magnification endoscopy (NBI-ME) for assessing premalignant gastric lesions during real-time examination. PATIENTS, MATERIALS AND METHODS: A total number of 59 patients were examined by NBI-ME and target biopsies of the antrum, corporeal, and incisura angularis levels. Modified endoscopic patterns were classified into three groups: type A [tubulo-villous mucosal pattern with regular microvessels, or the light blue crest (LBC) sign], type B [disappearance of normal subepithelial capillary network (SECN) pattern], and type C [irregular mucosal pattern (IMP) and∕or irregular vascular pattern (IVP)]. The endoscopic diagnosis was compared to histological findings (the gold standard). The NBI-ME results were assessed for accuracy, sensitivity, specificity, and negative and positive predictive values in detecting intestinal metaplasia, atrophic gastritis and dysplasia. RESULTS: Analysis of endoscopic patterns showed a good correlation with premalignant lesions (p<0.05). Type A pattern showed 80.2% accuracy, 80.43% sensitivity and 80% specificity [area under receiver operating characteristic (AUROC) of 0.8] in detecting intestinal metaplasia. Diagnostic performance for assessment of atrophic gastritis was not ideal (69.5% accuracy, 83.72% sensitivity, 56.04% specificity, AUROC 0.69). Pattern C represents a reliable endoscopic marker for the diagnosis of dysplasia (91.1% accuracy, 83.3% sensitivity, 91.81% specificity, AUROC 0.87). The extension of precancerous lesions was estimated during endoscopic examination. CONCLUSIONS: NBI-ME represents a valuable tool in the assessment of premalignant gastric lesions, thereby categorizing patients into low and high risks of developing gastric cancer. The applicability of the method in routine practice is promising, as it helps shape the follow up protocol of patients with premalignant lesions of the stomach. It is worth mentioning that, this method requires standardization, additional training, and expertise.

A preliminary feasibility study: Narrow-band imaging targeted versus standard white light endoscopy non-targeted biopsies in a surveillance Barrett's population.

BACKGROUND: Narrow band imaging (NBI) is used in the detection of intestinal metaplasia (IM) and dysplasia in patients with Barrett's oesophagus (BE). AIMS: The study compared the usefulness of NBI with white-light standard endoscopy (WLSE) for the detection of dysplasia and IM in BE and determined the prediction of the histological diagnosis according to the mucosal and vascular patterns obtained by NBI. PATIENTS AND METHODS: A total of 84 patients were prospectively enrolled in the study. Every patient underwent a WLSE with random biopsies and after 4-6 weeks, a NBI examination was performed. RESULTS: NBI detected significant more IM positive biopsies than WLSE (74.5% vs. 35.9%; p<0.0001) and significant more patients with low grade dysplasia (LGD) (7.1% vs. 0%; p=0.03). Taking biopsy samples from the villous pattern determined the diagnosis of IM (80%) and biopsies from the area covered by the irregular pattern lead to the identification of LGD in 45.4% of the cases and indefinite dysplasia (ID) in 18.2% of the cases. CONCLUSION: A thorough analysis of NBI patterns may lead to real-time IM diagnosis in the absence of the histological examination and may require targeted biopsies from the areas with an irregular pattern for diagnosing dysplasia.