Gastric cancer (GC) is the third leading cause of cancer mortality and the fifth for incidence worldwide. Metaplastic atrophic gastritis (MAG), which is the replacement of the oxyntic mucosa by pseudopyloric metaplasia (PPM), intestinal metaplasia (IM), or fibrosis, represents a precancerous condition on which GC could develop. Electronic chromoendoscopy (EC) is a technique that enhances the visualization of surface and vascular patterns and is able to diagnose IM and cancerous conditions with high accuracy, permitting to perform targeted biopsies instead of random biopsies. Recently, a new classification (Endoscopic grading of gastric intestinal metaplasia ¿ EGGIM) based on the diagnosis and staging of IM by the use of EC, was proposed and then validated. Regarding surveillance for MAG, evidence is scarce and the correct follow-up strategy is still debated.
This project is composed of 3 parts:
1.To investigate the role of PPM in the risk of GC and the use of EC for targeting biopsies to assess the correct biopsy protocol to diagnose this condition: a longitudinal cohort study conducted on patients with metaplastic and non-metaplastic atrophic gastritis with the use of EC and EGGIM classification for the diagnosis of PPM and the associated risk of GC.
2. To investigate the role of EC and, in particular, blue-light imaging (BLI) in the diagnosis and staging of IM using the EGGIM classification: a prospective study based on the comparison of BLI targeted biopsies versus the updated Sydney system protocol with traditional white light scopes with the use of EGGIM classification to stage the presence of IM and the risk of GC.
3. To define the most appropriate endoscopic follow-up for the different patients with gastric precancerous conditions considering clinical, endoscopic and histological aspects in a prospective randomized study where patients will be randomized to different endoscopic follow-up based on clinical, endoscopic and histological characteristics.
The value and feasibility of the research program are based on the following issues:
1. In the last 30 years, the research group has built a cohort of patients with MAG, collecting serological and histological specimens.
2. The research group is composed of gastroenterologists and endoscopists with specific clinical expertise on precancerous and cancerous conditions of the stomach and collaborate with national and international research networks on this research topics.
3. The proponent and the participants form together a research group with a specific scientific background in the field of MAG precancerous and cancerous conditions of the stomach, whose projects have been granted by University Sapienza in the last 20 years.
1.To investigate the role of PPM in the risk of GC and the use of EC for targeting biopsies to assess the correct biopsy protocol to diagnose this condition: a longitudinal cohort study conducted on patients with metaplastic and non-metaplastic atrophic gastritis with the use of EC and EGGIM classification for the diagnosis of PPM and the associated risk of GC.
EXPECTED RESULTS: to assess the endoscopic features of PPM at electronic chromoendoscopy and to assess the most appropriate biopsy strategy for the diagnosis of PPM, analyzing its role in the development of GC.
2. To investigate the role of BLI in the diagnosis and staging of IM using the EGGIM classification: a prospective study based on the comparison of BLI targeted biopsies versus the updated Sydney system protocol with traditional white light (WL) scopes with the use of EGGIM classification to stage the presence of IM and the risk of GC.
EXPECTED RESULTS: to assess the higher accuracy of BLI compared to WLE. BLI would enable to assess the extension of GIM without the need for biopsies. If observed, this would overall improve the upper GI endoscopy accuracy saving costs of predictably negative gastric biopsies.
3. To define the most appropriate endoscopic follow-up for the different patients with gastric precancerous conditions considering clinical, endoscopic and histological aspects in a prospective randomized study where patients will be randomized to different endoscopic follow-up based on clinical, endoscopic and histological characteristics.
EXPECTED RESULTS: This prospective study will be the first study to investigate the natural history of gastric premalignant conditions in this new age of electronic chromoendoscopy imaging, so based not only on random biopsies (as it was described before) but based simultaneously on targeted biopsies. Moreover, it can help us to define which clinical factors influence most gastric cancer risk and which is the best way to determine and stage advanced gastric premalignant conditions (histology or endoscopy or both).