The evolving role of endoscopy in the diagnosis of premalignant gastric lesions

Abstract

Gastric adenocarcinoma is a disease that is often detected late, at a stage when curative treatment is unachievable. This must be addressed through changes in our approach to the identification of patients at increased risk by improving the detection and risk assessment of premalignant changes in the stomach, including chronic atrophic gastritis and intestinal metaplasia. Current guidelines recommend utilising random biopsies in a pathology-led approach in order to stage the extent and severity of gastritis and intestinal metaplasia. This random method is poorly reproducible and prone to sampling error and fails to acknowledge recent advances in our understanding of the progression to gastric cancer as a non-linear, branching evolutionary model. Data suggest that recent advances in endoscopic imaging modalities, such as narrow band imaging, can achieve a high degree of accuracy in the stomach for the diagnosis of these premalignant changes. In this review, we outline recent data to support a paradigm shift towards an endoscopy-led approach to diagnosis and staging of premalignant changes in the stomach. High-quality endoscopic interrogation of the chronically inflamed stomach mucosa, supported by targeted biopsies, will lead to more accurate risk assessment, with reduced rates of under or missed diagnoses.

Recent advances in the detection and management of early gastric cancer and its precursors

“…A shift towards an endoscopy-led staging approach in the stomach may facilitate more robust assessment to allow a more accurate and tailored approach to cancer surveillance and early detection for high-risk individuals. 15 The advances in therapeutics in endoscopy including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have transformed the management of EGC. ESD has become the technique of choice and is now the gold standard given its high en bloc resection rates, lower local recurrence and excellent 5-year survival rates as high as 92.6%.…”

“…These findings should be documented with their location and extent, including the simplified Kimura-Takemoto system (figure 1D,E) (normal; limited atrophy: antral (C1); antral predominant (C2); and extended atrophy: corpus predominant (C3) and panatrophy) and finally, obtain targeted biopsies from areas endoscopically suspicious for GIM in areas of the updated Sydney protocol. 15…”

Premalignant lesions and gastric cancer: Current understanding

“…In normal gastric epithelium stem cell populations give rise to nascent epithelial cells that mature and differentiate as they migrate to the apex of the gland[33]. Gastric and intestinal stem cells share an endodermal lineage, and through the process of chronic inflammation gastric stem cells may reprogram, producing metaplastic intestinal-type epithelium that replaces the normal gastric mucosa[34]. The continuing chronic inflammatory process results in further accumulation of genetic lesions in stem cells, ultimately resulting in dysplasia and cancer.…”

“…Although the exact genomic or epigenomic pathways for IM progression to dysplasia are still being investigated, it is possible to postulate how certain events are necessary for progression by combining available data from a small number of key studies. It is known that: (1) IM is clonally derived from within the gastric mucosa[34,85]; (2) Gastric and IM glands divide by fission to form clonal patches[34,85,86]; (3) Over time, different gastric stem cells with accumulated genomic events (somatic mutations/ chromosomal copy number gains and/or losses) can give rise to unique IM glands; (4) Further genomic changes may drive IM glands to proliferate or persist over a long period of time; (5) Dysplastic glands are formed that are genetically related to IM glands; entire dysplastic fields can share a foundation mutation[86] from which multiple subclones can result; and (6) This event can happen simultaneously in multiple regions of the stomach leading to an increased risk of GC developing across several locations and therefore providing a field cancerization effect.…”

Laser Video Fluorescence Diagnosis of Stomach Diseases

“…The main method of gastric cancer diagnosis providing morphological confirmation is endoscopic examination [2]. At present, various technologies making standard gastroscopy more effective and precise are being developed.…”