Performance status of targeted biopsy alone versus Sydney protocol by non-NBI expert gastroenterologist in gastric intestinal metaplasia diagnosis

Background and study aims According to a recent guideline, patients with gastric intestinal metaplasia (GIM) should have at least five biopsies performed under the Sydney protocol to evaluate for risk of extensive GIM. However, only narrow-band imaging (NBI)-targeted biopsy may be adequate to diagnose extensive GIM. Patients and methods A cross-sectional study was conducted between November 2019 and October 2020. Patients with histology-proven GIM were enrolled. All patients underwent standard esophagogastroduodenoscopy performed by a gastroenterology trainee. The performing endoscopists took biopsies from either a suspected GIM area (NBI-targeted biopsy) or randomly (if negative for GIM read by NBI) to complete five areas of the stomach as per the Sydney protocol. The gold standard for GIM diagnosis was pathology read by two gastrointestinal pathologists with unanimous agreement. Results A total of 95 patients with GIM were enrolled and 50 (52.6%) were men with a mean age of 64 years. Extensive GIM was diagnosed in 43 patients (45.3%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NBI-targeted biopsy vs. the Sydney protocol were 88.4% vs.100 %, 90.3% vs. 90.3%, 88.4% vs. 89.6%, 90.3% vs. 100%, and 89.5% vs. 94.7%, respectively. The number of specimens from NBI-targeted biopsy was significantly lower than that from Sydney protocol (311vs.475, P < 0.001). Conclusions Both NBI-targeted biopsy and Sydney protocol by a gastroenterologist who was not an expert in NBI and who has experience with diagnosis of at least 60 cases of GIM provided an NPV higher than 90%. Thus, targeted biopsy alone with NBI, which requires fewer specimens, is an alternative option for extensive GIM diagnosis.