Endoscopic grading of gastric intestinal metaplasia (EGGIM): a multicenter validation study

BACKGROUND

Random biopsies are recommended to identify individuals at risk of gastric adenocarcinoma. Cumulative evidence suggests that narrow-band imaging (NBI) can be used to grade gastric intestinal metaplasia (GIM). We aimed to externally validate a classification of endoscopic grading of gastric intestinal metaplasia (EGGIM).

METHODS

Consecutive patients in two centers were submitted to high resolution white-light gastroscopy followed by NBI to estimate EGGIM - a score (0 - 10) resulting from the sum of endoscopic assessments of GIM, scored as 0, 1, or 2 for no GIM, ≤ 30 %, or > 30 % of the mucosa, respectively, in five areas (lesser and greater curvature of both antrum and corpus, and incisura). If GIM was endoscopically suspected, targeted biopsies were performed; if GIM was not noticeable, random biopsies were performed according to the Sydney system to estimate the operative link on gastric intestinal metaplasia (OLGIM; the gold standard).

RESULTS

250 patients (62 % female; median age 55 years) were included. GIM was staged as OLGIM 0, I, II, III, IV in 136 (54 %), 15 (6 %), 52 (21 %), 34 (14 %), and 13 (5 %) patients, respectively. All patients with GIM except three were identifiable with targeted biopsies. For the diagnosis of OLGIM III/IV, the area under the ROC curve was 0.96 (95 % confidence interval [CI] 0.93 - 0.98) and by using the cutoff > 4, sensitivity, specificity, and positive likelihood ratio were 89 %, 95 %, and 16.5, respectively; results were similar (91 %, 95 %, and 18.1) when excluding patients with foveolar hyperplasia.

CONCLUSIONS

For the first time, an endoscopic approach was externally validated to determine the risk of gastric cancer without the need for biopsies. This can be used to simplify and individualize the management of patients with gastric precancerous conditions.

Narrow band imaging characteristics of gastric polypoid lesions: a single-center prospective pilot study

INTRODUCTION

Gastric polypoid lesions (GPL) are endoscopic findings whose histological nature is difficult to determine with white-light endoscopy. Hyperplastic polyps (HP), type-1 gastric carcinoids (T1-GC) and adenomas are the most frequent GPL needing different management. Narrow-band imaging (NBI) has high accuracy for gastric malignant lesions but few studies assessed whether GPL display specific NBI characteristics. We aimed to investigate the endoscopic NBI appearances of GPL.

MATERIALS AND METHODS

During gastroscopies, images of GPL were recorded, and lesions were removed for histological evaluation. Two endoscopists blindly reviewed the digital images and registered the endoscopic NBI appearances on a specific check-list. GPL were categorized in HP, adenomas and T1-GC using histology as gold standard.

RESULTS

Overall 52 GPL, observed in 40 patients [F55%; age 63 (36-85) years], were included: 29 (55.8%) HP; 18 (34.6%) T1-GC; 5 (9.6%) adenomas. The median size was seven (2-35) mm. A regular circular mucosal pattern was more frequently observed in HP and T1-GC compared to adenomas (P < 0.001). T1-GC showed a central erosion in 77.8% (P < 0.001 versus HP) with a clear demarcation line in 33.3%. Adenomas had tubule-villous mucosal pattern in 80% (P = 0.01 versus other lesions).

CONCLUSION

NBI analysis of the mucosal pattern seems to be effective to endoscopically discriminate between adenomas and HP while the main characteristic of T1-GC seems to be the presence of a central erosion, sometimes with demarcation line. The endoscopic NBI characterization of GPL may contribute to optimize the management of these lesions.