Endoscopic diagnosis and treatment of gastric dysplasia and early cancer: Current evidence and what the future may hold

Abstract

Gastric cancer accounts for a significant proportion of worldwide cancer-related morbidity and mortality. The well documented precancerous cascade provides an opportunity for clinicians to detect and treat gastric cancers at an endoscopically curable stage. In high prevalence regions such as Japan and Korea, this has led to the implementation of population screening programs. However, guidelines remain ambiguous in lower prevalence regions. In recent years, there have been many advances in the endoscopic diagnosis and treatment of early gastric cancer and precancerous lesions. More advanced endoscopic imaging has led to improved detection and characterization of gastric lesions as well as superior accuracy for delineation of margins prior to resection. In addition, promising early data on artificial intelligence in gastroscopy suggests a future role for this technology in maximizing the yield of advanced endoscopic imaging. Data on endoscopic resection (ER) are particularly robust in Japan and Korea, with high rates of curative ER and markedly reduced procedural morbidity. However, there is a shortage of data in other regions to support the applicability of protocols from these high prevalence countries. Future advances in endoscopic therapeutics will likely lead to further expansion of the current indications for ER, as both technology and proceduralist expertise continue to grow.

Keywords: Endoscopic imaging; Endoscopic mucosal resection; Endoscopic submucosal dissection; Endoscopy; Gastric cancer.

Figure 1

White light endoscopy compared to narrow-band imaging in gastric lesions, demonstrating clear demarcation lines and irregular microvascular/microsurface patterns on narrow-band imaging. A: Early gastric cancer at the incisura seen on white light endoscopy (WLE); B: The same lesion seen on narrow-band imaging (NBI) (blue arrows); C: Early gastric cancer in the antrum seen on WLE; D: The same lesion seen on NBI (blue arrows).

Figure 2

Narrow-band imaging demonstrating the ‘light blue crest’ (orange arrows) consistent with intestinal metaplasia.

Figure 3

Gastric body lesion with low-grade dysplasia seen on multiple forms of endoscopic imaging. A: White light endoscopy; B: Texture and colour enhancement imaging; C: Narrow-band imaging (NBI); D: high-magnification NBI.

Figure 4

Magnetic anchor-guided endoscopic submucosal dissection[169]. Citation: Mortagy M, Mehta N, Parsi MA, Abe S, Stevens T, Vargo JJ, Saito Y, Bhatt A. Magnetic anchor guidance for endoscopic submucosal dissection and other endoscopic procedures. World J Gastroenterol 2017; 23: 2883-2890. ©The Author(s) 2017. Published by Baishideng Publishing Group Inc.

Figure 5

Endoscopic submucosal dissection using an additional working channel[172]. A: Lesion marked via usual working channel; B: Submucosal injection; C: Near-circumferential incision made; D: Lesion grasped for countertraction via additional working channel while dissection underway. Citation: Knoop RF, Wedi E, Petzold G, Bremer SCB, Amanzada A, Ellenrieder V, Neesse A, Kunsch S. Endoscopic submucosal dissection with an additional working channel (ESD+): a novel technique to improve procedure time and safety of ESD. Surg Endosc 2021; 35: 3506-3512. ©The Author(s) 2021. Published by Springer Open Access Article.

Figure 6

‘Endo-lifter’ (Olympus-Tokyo, Japan)[192]. Citation: Harlow C, Sivananthan A, Ayaru L, Patel K, Darzi A, Patel N. Endoscopic submucosal dissection: an update on tools and accessories. Ther Adv Gastrointest Endosc 2020; 13: 2631774520957220. ©The Author(s) 2020. Published by Open Access Article.

Figure 7

Spring and loop clip traction[193]. Citation: Nagata M, Fujikawa T, Munakata H. Comparing a conventional and a spring-and-loop with clip traction method of endoscopic submucosal dissection for superficial gastric neoplasms: a randomized controlled trial (with videos). Gastrointest Endosc 2021; 93: 1097-1109. ©The Author(s) 2021. Published by Open Access Article.

Figure 8

Modified endo-clip and snare[185]. A-C: Multiple clips used to provide multifocal traction; D-F: Clip applied to opposing gastric wall for countertraction. Citation: Zhang Q, Yao X, Wang Z. A modified method of endoclip-and-snare to assist in endoscopic submucosal dissection with mucosal traction in the upper GI tract. VideoGIE 2018; 3: 137-141. ©The Author(s) 2018. Published by Open Access Article.

Figure 9

‘Over-the-scope clip’ (Ovesco, Germany) full-thickness resection[194]. Citation: Mão de-Ferro S, Castela J, Pereira D, Chaves P, Dias Pereira A. Endoscopic Full-Thickness Resection of Colorectal Lesions with the New FTRD System: Single-Center Experience. GE Port J Gastroenterol 2019; 26: 235-241. ©The Author(s) 2019. Published by Open Access Article.