AGA Clinical Practice Update on Screening and Surveillance in Individuals at Increased Risk for Gastric Cancer in the United States: Expert Review

Abstract

Description: Gastric cancer (GC) is a leading cause of preventable cancer and mortality in certain US populations. The most impactful way to reduce GC mortality is via primary prevention, namely Helicobacter pylori eradication, and secondary prevention, namely endoscopic screening and surveillance of precancerous conditions, such as gastric intestinal metaplasia (GIM). An emerging body of evidence supports the possible impact of these strategies on GC incidence and mortality in identifiable high-risk populations in the United States. Accordingly, the primary objective of this American Gastroenterological Association (AGA) Clinical Practice Update (CPU) Expert Review is to provide best practice advice for primary and secondary prevention of GC in the context of current clinical practice and evidence in the United States.

Methods: This CPU Expert Review was commissioned and approved by the AGA Institute CPU Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPU Committee and external peer review through standard procedures of Gastroenterology. These best practice advice statements were drawn from a review of the published literature and expert opinion. Because systematic reviews were not performed, these best practice advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: There are identifiable high-risk groups in the United States who should be considered for GC screening. These include first-generation immigrants from high-incidence GC regions and possibly other non-White racial and ethnic groups, those with a family history of GC in a first-degree relative, and individuals with certain hereditary gastrointestinal polyposis or hereditary cancer syndromes. BEST PRACTICE ADVICE 2: Endoscopy is the best test for screening or surveillance in individuals at increased risk for GC. Endoscopy enables direct visualization to endoscopically stage the mucosa and identify areas concerning for neoplasia, as well as enables biopsies for further histologic examination and mucosal staging. Both endoscopic and histologic staging are key for risk stratification and determining whether ongoing surveillance is indicated and at what interval. BEST PRACTICE ADVICE 3: High-quality upper endoscopy for the detection of premalignant and malignant gastric lesions should include the use of a high-definition white-light endoscopy system with image enhancement, gastric mucosal cleansing, and insufflation to achieve optimal mucosal visualization, in addition to adequate visual inspection time, photodocumentation, and use of a systematic biopsy protocol for mucosal staging when appropriate. BEST PRACTICE ADVICE 4: H pylori eradication is essential and serves as an adjunct to endoscopic screening and surveillance for primary and secondary prevention of GC. Opportunistic screening for H pylori infection should be considered in individuals deemed to be at increased risk for GC (refer to Best Practice Advice 1). Screening for H pylori infection in adult household members of individuals who test positive for H pylori (so-called "familial-based testing") should also be considered. BEST PRACTICE ADVICE 5: In individuals with suspected gastric atrophy with or without intestinal metaplasia, gastric biopsies should be obtained according to a systematic protocol (eg, updated Sydney System) to enable histologic confirmation and staging. A minimum of 5 total biopsies should be obtained, with samples from the antrum/incisura and corpus placed in separately labeled jars (eg, jar 1, "antrum/incisura" and jar 2, "corpus"). Any suspicious areas should be described and biopsied separately. BEST PRACTICE ADVICE 6: GIM and dysplasia are endoscopically detectable. However, these findings often go undiagnosed when endoscopists are unfamiliar with the characteristic visual features; accordingly, there is an unmet need for improved training, especially in the United States. Artificial intelligence tools appear promising for the detection of early gastric neoplasia in the adequately visualized stomach, but data are too preliminary to recommend routine use. BEST PRACTICE ADVICE 7: Endoscopists should work with their local pathologists to achieve consensus for consistent documentation of histologic risk-stratification parameters when atrophic gastritis with or without metaplasia is diagnosed. At a minimum, the presence or absence of H pylori infection, severity of atrophy and/or metaplasia, and histologic subtyping of GIM, if applicable, should be documented to inform clinical decision making. BEST PRACTICE ADVICE 8: If the index screening endoscopy performed in an individual at increased risk for GC (refer to Best Practice Advice 1) does not identify atrophy, GIM, or neoplasia, then the decision to continue screening should be based on that individual's risk factors and preferences. If the individual has a family history of GC or multiple risk factors for GC, then ongoing screening should be considered. The optimal screening intervals in such scenarios are not well defined. BEST PRACTICE ADVICE 9: Endoscopists should ensure that all individuals with confirmed gastric atrophy with or without GIM undergo risk stratification. Individuals with severe atrophic gastritis and/or multifocal or incomplete GIM are likely to benefit from endoscopic surveillance, particularly if they have other risk factors for GC (eg, family history). Endoscopic surveillance should be considered every 3 years; however, intervals are not well defined and shorter intervals may be advisable in those with multiple risk factors, such as severe GIM that is anatomically extensive. BEST PRACTICE ADVICE 10: Indefinite and low-grade dysplasia can be difficult to reproducibly identify by endoscopy and accurately diagnose on histopathology. Accordingly, all dysplasia should be confirmed by an experienced gastrointestinal pathologist, and clinicians should refer patients with visible or nonvisible dysplasia to an endoscopist or center with expertise in the diagnosis and management of gastric neoplasia. Individuals with indefinite or low-grade dysplasia who are infected with H pylori should be treated and have eradication confirmed, followed by repeat endoscopy and biopsies by an experienced endoscopist, as visual and histologic discernment may improve once inflammation subsides. BEST PRACTICE ADVICE 11: Individuals with suspected high-grade dysplasia or early GC should undergo endoscopic submucosal dissection with the goal of en bloc, R0 resection to enable accurate pathologic staging with curative intent. Eradication of active H pylori infection is essential, but should not delay endoscopic intervention. Endoscopic submucosal dissection should be performed at a center with endoscopic and pathologic expertise. BEST PRACTICE ADVICE 12: Individuals with a history of successfully resected gastric dysplasia or cancer require ongoing endoscopic surveillance. Suggested surveillance intervals exist, but additional data are required to refine surveillance recommendations, particularly in the United States. BEST PRACTICE ADVICE 13: Type I gastric carcinoids in individuals with atrophic gastritis are typically indolent, especially if <1 cm. Endoscopists may consider resecting gastric carcinoids <1 cm and should endoscopically resect lesions measuring 1-2 cm. Individuals with type I gastric carcinoids >2 cm should undergo cross-sectional imaging and be referred for surgical resection, given the risk of metastasis. Individuals with type I gastric carcinoids should undergo surveillance, but the intervals are not well defined. BEST PRACTICE ADVICE 14: In general, only individuals who are fit for endoscopic or potentially surgical treatment should be screened for GC and continued surveillance of premalignant gastric conditions. If a person is no longer fit for endoscopic or surgical treatment, then screening and surveillance should be stopped. BEST PRACTICE ADVICE 15: To achieve health equity, a personalized approach should be taken to assess an individual's risk for GC to determine whether screening and surveillance should be pursued. In conjunction, modifiable risk factors for GC should be distinctly addressed, as most of these risk factors disproportionately impact people at high risk for GC and represent health care disparities.

Keywords: Atrophic Gastritis; Cancer Prevention; Disparity; Epidemiology; Gastric Intestinal Metaplasia; Helicobacter pylori.