Hyperspectral imaging (HSI) enables visualisation of morphological and biochemical information, which could improve disease diagnostic accuracy. Unfortunately, the wide range of image distortions that arise during flexible endoscopy in the clinic have made integration of HSI challenging. To address this challenge, we demonstrate a hyperspectral endoscope (HySE) that simultaneously records intrinsically co-registered hyperspectral and standard-of-care white light images, which allows image distortions to be compensated computationally and an accurate hyperspectral data cube to be reconstructed as the endoscope moves in the lumen. Evaluation of HySE performance shows excellent spatial, spectral and temporal resolution and high colour fidelity. Application of HySE enables: quantification of blood oxygenation levels in tissue mimicking phantoms; differentiation of spectral profiles from normal and pathological ex vivo human tissues; and recording of hyperspectral data under freehand motion within an intact ex vivo pig oesophagus model. HySE therefore shows potential for enabling HSI in clinical endoscopy.

Intestinal metaplasia in the esophagus (Barrett's esophagus IM, or BE-IM) and stomach (GIM) are considered precursors for esophageal and gastric adenocarcinoma, respectively. We hypothesize that BE-IM and GIM follow parallel developmental trajectories in response to differing inflammatory insults. Here, we construct a single-cell RNA-sequencing atlas, supported by protein expression studies, of the entire gastrointestinal tract spanning physiologically normal and pathologic states including gastric metaplasia in the esophagus (E-GM), BE-IM, atrophic gastritis, and GIM. We demonstrate that BE-IM and GIM share molecular features, and individual cells simultaneously possess transcriptional properties of gastric and intestinal epithelia, suggesting phenotypic mosaicism. Transcriptionally E-GM resembles atrophic gastritis; genetically, it is clonal and has a lower mutational burden than BE-IM. Finally, we show that GIM and BE-IM acquire a protumorigenic, activated fibroblast microenvironment. These findings suggest that BE-IM and GIM can be considered molecularly similar entities in adjacent organs, opening the path for shared detection and treatment strategies. Significance: Our data capture the gradual molecular and phenotypic transition from a gastric to intestinal phenotype (IM) in the esophagus and stomach. Because BE-IM and GIM can predispose to cancer, this new understanding of a common developmental trajectory could pave the way for a more unified approach to detection and treatment. See related commentary by Stachler, p. 1291. This article is highlighted in the In This Issue feature, p. 1275

Background A significant proportion of upper gastrointestinal cancers (UGICs) remain undetected during esophagogastroduodenoscopy (EGD). We investigated the characteristics and risk factors of UGICs missed during endoscopy. Methods In this nationwide registry-based study, we analyzed two large Polish datasets (National Health Fund and National Cancer Registry) to identify individuals who underwent EGD and were subsequently diagnosed with UGIC. Cancers diagnosed < 6 months after EGD were defined as “prevalent” and those within ≥ 6– < 36 months as “missed.” We compared the characteristics of missed and prevalent cancers, and analyzed the risk factors for missed UGICs in a multivariable regression model. Results We included 4 105 399 patients (mean age 56.0 years [SD 17.4]; 57.5 % female) who underwent 5 877 674 EGDs in 2012–2018. Within this cohort, 33 241 UGICs were diagnosed, of which 1993 (6.0 %) were missed. Within esophageal neoplasms, adenocarcinomas were more frequently missed than squamous cell cancers (6.1 % vs. 4.2 %), with a relative risk of 1.4 (95 % confidence interval [CI] 1.1–1.8, P = 0.01). Most gastric cancers were adenocarcinomas, of which 5.7 % were classified as missed. Overall, a higher proportion of missed UGICs than prevalent cancers presented at an advanced stage (42.2 % vs. 36.2 %, P < 0.001). Risk factors for missed UGICs included initial EGD performed within primary (vs. secondary) care (odds ratio [OR] 1.3, 95 %CI 1.2–1.5), female sex (OR 1.3, 95 %CI 1.2–1.4), and higher comorbidity (Charlson comorbidity index ≥ 5 vs. 0; OR 6.0, 95 %CI 4.7–7.5). Conclusions Among UGICs, esophageal adenocarcinomas were missed most frequently. Missed cancers occur more frequently within the primary care sector and are found more often in women and individuals with multiple comorbidities.

Background: Gastric cancer (GC) remains the fifth most common cancer and the third most common cause of cancer-related death globally. In 2022, GC fell into the scope of the updated EU recommendations for targeted cancer screening. Given the growing awareness of the GC burden, we aimed to review the existing screening strategies for GC in high-risk regions and discuss potentially applicable modalities in countries with low-to-intermediate incidence. Methods: The references for this Review article were identified through searches of PubMed with the search terms “gastric cancer”, “stomach cancer”, “Helicobacter pylori”, and “screening” over the period from 1995 until August 2022. Results: As Helicobacter pylori (H. pylori)-induced gastritis is the primary step in the development of GC, the focus on GC prevention may be directed toward testing for and treating this infection. Such a strategy may be appealing in countries with low- and intermediate- GC incidence. Other biomarker-based approaches to identify at-risk individuals in such regions are being evaluated. Within high-incidence areas, both primary endoscopic screening and population-based H. pylori “test-and-treat” strategies represent cost-effective models. Conclusions: Given the significant variations in GC incidence and healthcare resources around the globe, screening strategies for GC should be adjusted to the actual conditions in each region. While several proven tools exist for accurate GC diagnosis, a universal modality for the screening of GC populations remains elusive.