Molecular Evolution of Metaplasia to Adenocarcinoma in the Esophagus

Esophageal Mucosal Resistance in Reflux Esophagitis: What We Have Learned So Far and What Remains to Be Learned

Gastroesophageal reflux disease (GERD) has the highest prevalence among diseases of the digestive system and is characterized by a significant decrease in patients' quality of life, comparable to arterial hypertension and coronary heart disease. One in every ten cases of reflux esophagitis leads to the formation of Barrett's esophagus, which is associated with a high risk of esophagus adenocarcinoma. The key factors determining the progression of the disease are the frequency and duration of the reflux of the stomach's contents. As a result, refluxate, which includes hydrochloric acid, pepsin, and, in the case of concomitant duodeno-gastric reflux, bile acids and lysolecithin, is thrown into the overlying sections of the digestive tract. At the same time, in addition to aggression factors, it is necessary to take into account the state of resistance in the esophageal mucosa to the effects of aggressive refluxate molecules. This review was prepared using systematized data on the protective properties of the esophageal mucosa and modern methods to assess the mucosal barrier in reflux esophagitis. Lesions of the epithelial barrier structure in the esophagus are recognized as the main pathogenetic factor in the development of reflux esophagitis and are a potentially significant therapeutic target in the treatment of GERD and Barrett's esophagus. This article presents the characteristics of the esophageal mucosal barrier and the protective mechanisms of the esophagus's mucous membrane in conditions of gastroesophageal reflux. Diagnostic approaches for assessing the course of reflux esophagitis are described for both histological criteria and the possibility of a comprehensive assessment of the state of mucins, tight-junction proteins, and the proliferative activity of the mucosa, including under the conditions of ongoing therapy.

Intestinal metaplasia in progression of Barrett's esophagus to esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has been increasing year by year. The prognosis of EAC is poor, and the 5-year survival rate is less than 20%. Barrett's esophagus (BE) is the only known precancerous lesion of EAC. BE with intestinal metaplasia (IM) has a higher risk of progressing to EAC. Exploring the mechanism of IM and finding targeted therapeutic targets for BE has become an important measure for tumor prevention. Bile acid reflux is considered an important factor in the occurrence of IM and promotes the progression of BE to EAC. However, the molecular regulatory mechanism of bile reflux induced IM and carcinogenesis remains unclear. This article reviews the environment, significance, and cell origin theory of IM, toxic effects of bile reflux, and molecular changes of IM progression to tumor, aiming to improve clinicians' understanding of IM in BE and provide evidence for early intervention of BE and prevention and treatment of EAC.

In vitro and in vivo phototoxicity on gastric mucosa induced by methylene blue

BACKGROUND

Methylene blue (MB) is used endoscopically to demarcate tumors and as a photosensitizer in photodynamic therapy (PDT). However, there are few in vivo studies about its toxicity in healthy stomach tissue. We performed sequential in vitro and in vivo analyses of MB-induced phototoxicity.

METHODS

We performed in vitro experiments using the AGS human gastric cancer cell line treated with light-emitting diode (LED) irradiation (3.6 J/cm²) and MB. Cytotoxicity was evaluated using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. In vivo toxicity was evaluated in the stomach of beagles using the same dose of fiber-optic LED via gastroscopy, after spraying 0.1% and 0.5% MB solutions. Stomach tissue was also evaluated using the TUNEL assay.

RESULTS

In vitro, increased concentrations of MB led to higher TUNEL scores. However, cell viability was significantly lower after MB plus LED irradiation than after treatment with MB alone (P < 0.001). In vivo, the TUNEL score was highest immediately after treatment with 0.1% or 0.5% MB plus light irradiation, and the score was significantly higher in the LED illumination plus MB group than in the control group (P < 0.05). The elevated TUNEL score was maintained for 3 days in the MB plus light irradiation group but returned to normal levels on day 10.

CONCLUSIONS

: Endoscopic light application with MB 0.5% concentration to the stomach may be regarded as a safe procedure despite some DNA injuries in the early period.

Progression of Barrett's esophagus, crypt dysplasia, and low-grade dysplasia diagnosed by wide-area transepithelial sampling with 3-dimensional computer-assisted analysis: a retrospective analysis

BACKGROUND AND AIMS

Wide-area transepithelial sampling with 3-dimensional computer-assisted analysis (WATS3D) is used as an adjunct to forceps biopsy sampling in Barrett's esophagus (BE). BE-associated crypt dysplasia (CD), which can be detected by WATS3D, involves crypts but not surface epithelium. The risk of neoplastic progression of CD has never been evaluated. The prognosis of WATS3D-diagnosed nondysplastic BE (NDBE) and low-grade dysplasia (LGD) is also unknown. We assessed the risk of progression of WATS3D-reported NDBE, CD, and LGD with high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC).

METHODS

We analyzed patients who underwent WATS3D in routine care. Eligible patients had 2 WATS3D ≥12 months apart. Patients were categorized by the initial WATS3D finding as NDBE, CD, or LGD. Patient-years of observation were calculated by multiplying the mean follow-up by the number of patients. Progression, defined as a subsequent finding of HGD/EAC on forceps biopsy sampling, was assessed. The crude progression rate was calculated, and Kaplan-Meier analysis compared progression rates stratified by baseline histology. Bivariate analysis identified progression risk factors.

RESULTS

Of 151,224 WATS3D cases, 43,145 (29%) had BE. Of these, 4545 patients had 2 WATS3D separated by ≥12 months. The mean follow-up was 1.97 years (range, 1.0-6.42). In patients with baseline NDBE, progression was .08% per patient-year (95% confidence interval [CI], .02%-.14%). Progression of baseline CD was significantly higher, at 1.42% per patient-year (95% CI, 0%-3.01%). For baseline LGD, progression was 5.79% per patient-year (95% CI, 1.02%-10.55%). Other risk factors for progression were increasing age and BE segment length.

CONCLUSIONS

NDBE found on WATS3D has a very low risk of progression. CD reported on WATS3D appears to be a neoplastic precursor lesion, with a risk of progression in this study significantly higher than NDBE but lower than LGD. The clinical utility of CD requires further investigation.

Expression of DNA Mismatch Repair Proteins, PD1 and PDL1 in Barrett's Neoplasia

BACKGROUND/AIM

Cancers with a microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) status respond to immune checkpoint inhibition (ICI). Regardless of the tumor type, MSI-H/dMMR status is a reliable biomarker for ICI responsiveness. This study aimed at determining the MSI-H status in precursor lesions to esophageal adenocarcinoma (EAC) such as Barrett's esophagus (BE) and BE with either low-grade dysplasia (LGD) or high-grade dysplasia (HGD).

PATIENTS AND METHODS

We performed immunohistochemical staining (IHC) for PMS2, MSH6, PD1, and PD-L1.

RESULTS

All cases of BE (50), LGD (48), and HGD (50) had intact PMS2 and MSH6 nuclear expression; were negative for PD1; and had a PD-L1 combined positive score (CPS) score <1. One EAC case (2%) was negative for PMS2 nuclear expression. One HGD case (2%) and two EAC cases (4%) were PD1 positive (CPS score <1 applied to PD1). One EAC case (2%) had a CPS score >1, and one EAC case (2%) was MSI-H. MSI-H tumors usually show PD-L1 expression, although the MSI-H EAC in this study had a PD-L1 CPS score of <1.

CONCLUSION

Further studies investigating EAC and its precursor lesions for PD1, PD-L1, and dMMR status may be informative regarding the immunogenicity of the evolution of EAC.

Intestinal metaplasia of the urinary tract harbors potentially oncogenic genetic variants

In the urinary tract, there is an uncertain relationship between intestinal metaplasia (IM), primary adenocarcinoma, and urothelial carcinoma. Although IM is usually found adjacent to concurrent urothelial carcinoma or adenocarcinoma, small retrospective series have shown that most bladder biopsies with only IM do not subsequently develop cancer. However, IM with dysplasia does seem to be associated with a higher risk of concurrent malignancy or progressing to cancer. Since the molecular landscape of these lesions has remained largely unexplored, there are significant uncertainties about the oncogenic potential of IM in the bladder and urethra. This study investigated the presence of potentially oncogenic genetic variants in cases of IM with and without dysplasia. Twenty-three (23) cases of IM (3 urethra, 20 bladder) were sequenced using a solid tumor next-generation sequencing panel. Of these, five contained IM with high-grade dysplasia (including a case with paired IM-adenocarcinoma and another with paired IM-urothelial carcinoma) and 18 lacked dysplasia. Oncogenic genetic variants were found in all cases of IM with high-grade dysplasia and in five non-dysplastic IM cases, including mutations and copy number variants commonly seen in primary adenocarcinoma of the bladder and urothelial carcinoma. This study demonstrates that IM can harbor potentially oncogenic genetic variants, suggesting that it might represent a cancer precursor or a marker of increased cancer risk in a subset of cases.

Towards screening Barrett's oesophagus: current guidelines, imaging modalities and future developments

Barrett's oesophagus is the only known precursor to oesophageal adenocarcinoma (OAC). Although guidelines on the screening and surveillance exist in Barrett's oesophagus, the current strategies are inadequate. Oesophagogastroduodenoscopy (OGD) is the gold standard method in screening for Barrett's oesophagus. This invasive method is expensive with associated risks negating its use as a current screening tool for Barrett's oesophagus. This review explores current definitions, epidemiology, biomarkers, surveillance, and screening in Barrett's oesophagus. Imaging modalities applicable to this condition are discussed, in addition to future developments. There is an urgent need for an alternative non-invasive method of screening and/or surveillance which could be highly beneficial towards reducing waiting times, alleviating patient fears and reducing future costs in current healthcare services. Vibrational spectroscopy has been shown to be promising in categorising Barrett's oesophagus through to high-grade dysplasia (HGD) and OAC. These techniques need further validation through multicentre trials.

A narrative review of Barrett's esophagus in 2020, molecular and clinical update

Barrett’s esophagus (BE) is a condition resulting from an acquired metaplastic epithelial change in the esophagus in response to gastroesophageal reflux. BE is the only known precursor lesion to esophageal adenocarcinoma, and can progress from non-dysplastic BE (NDBE) to low grade dysplasia (LGD) and high grade dysplasia (HGD), and ultimately invasive carcinoma. Although the risk of developing esophageal adenocarcinoma (EAC) in NBDE is less than 0.5% per year, there has been a rising incidence of EAC in Western countries, which continue to drive efforts to optimize screening and surveillance methods. The current gold standard for diagnosis is esophagogastroduodenoscopy (EGD), and there has been significant interest in alternative, minimally invasive methods for screening which would be more readily accessible in the primary care setting. Surveillance endoscopy in 3–5 years is recommended for NDBE given the low progression to EAC. The mainstay of treatment for LGD and HGD is endoscopic eradication therapy (EET). Visible lesions are treated with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Radiofrequency ablation (RFA) is considered first line therapy for flat dysplastic BE and cryotherapy has shown promising results as an alternate form of treatment for of dysplasia. The molecular progression of BE to EAC is a complex process involving multiple pathways involving genetic and epigenetic modifications. Genomic studies have further led to the understanding of the complex molecular landscape that occurs early and late in the disease process. Promising biomarker panels have been investigated to help with the diagnosis of BE as well as aid in the risk stratification of BE during surveillance. In addition, clinical prediction models have been developed to categorize BE patients in low, intermediate, and high risk for progression to HGD and EAC. Further clinical and translational research is needed to help refine markers and techniques in diagnosis, screening, and surveillance.

CDX-2 Expression in Esophageal Biopsies Without Goblet Cell Intestinal Metaplasia May Be Predictive of Barrett's Esophagus

BACKGROUND

CDX-2 is a nuclear homeobox transcription factor not normally expressed in esophageal and gastric epithelia, reported to highlight intestinal metaplasia (IM) in the esophagus. Pathological absence of goblet cells at initial screening via hematoxylin and eosin (HE) and alcian blue (AB) staining results in patient exclusion from surveillance programs.

AIMS

This study aimed to determine whether non-goblet cell IM, as defined by CDX-2 positivity, can be considered to be a precursor to Barrett's esophagus (BE).

METHODS

This study received IRB approval (17,284). Patients with gastroesophageal reflux disease (n = 181) who underwent upper-gastrointestinal endoscopy with biopsies of the distal esophagus to rule out BE using HE/AB staining and CDX-2 immunostaining were followed for 3 years. Initial and follow-up staining results were evaluated for age/sex.

RESULTS

Differences between development of goblet cell IM in CDX-2-negative and CDX-2-positive groups were evaluated. A Kaplan-Meier curve showed that, out of the 134 patients initially positive for CDX-2, 25 (18.7%) had developed goblet cell IM after 2 years and 106 (79.1%) after 3 years. Conversely, of the 47 patients initially negative for CDX-2, 8 (17.9%) developed goblet cell IM after 24 months and only 11 (23.8%) after 40 to 45 months (P = .049; age-adjusted Cox proportional hazard regression model).

CONCLUSION

In cases that are initially AB negative and CDX-2 positive, CDX-2 was demonstrated to have a potential prognostic utility for early detection of progression to BE. CDX-2 expression is significantly predictive for risk of goblet cell IM development 40 to 45 months after initial biopsy.

No Barrett's-No Cancer: A Proposed New Paradigm for Prevention of Esophageal Adenocarcinoma

Esophageal adenocarcinoma is inflammation-associated cancer with a recognizable preneoplastic stage, Barrett's. Barrett's describes the metaplastic transformation of esophageal squamous mucosa into columnar epithelium that typically results secondary to mucosal damage caused by acidic gastroduodenal reflux. Continued acid reflux may then result in mucosal inflammation which results in progressive inflammation-induced genetic instability that may eventuate in esophageal adenocarcinoma. Barrett's is the only recognized precursor lesion to esophageal carcinoma. Barrett's mucosa is unique among preneoplastic lesions; ablation therapy results in restitution of a squamous epithelium reducing or eliminating accumulated genetic instabilities and resetting the biological clock progressing toward invasive cancer. However, recurrence of Barrett's after ablation is common. We propose that both Barrett's and recurrence of Barrett's after ablation can be prevented and discuss how current approaches to therapy for gastroesophageal reflux disease, for Barrett's screening, chemoprevention, and ablation therapy all might be reconsidered. We propose (1) improved approaches to Barrett's prevention, (2) universal Barrett's screening by linking Barrett's screening to colon cancer screening, (3) ablation of all Barrett's mucosa along with (4) acid-suppressive-antireflux therapy tailored to prevent development of Barrett's or the recurrence of Barrett's after ablation therapy. We propose that ultimately, treatment decisions for gastroesophageal reflux disease and prevention of Barrett's and esophageal carcinoma should be based on assessing and maintaining esophageal mucosal integrity. This will require development and verification of specific measurements that reliably correlate with prevention of Barrett's. We outline the new research and technical advances needed to cost-effectively achieve these goals.

Maspin differential expression patterns as a potential marker for targeted screening of esophageal adenocarcinoma/gastroesophageal junction adenocarcinoma

AIM

Barrett's esophagus (BE) is a predisposing factor of esophageal adenocarcinoma/gastroesophageal junction adenocarcinoma (ECA/GEJ Aca). BE patients are stratified and subsequently monitored according to the risk of malignant progression by the combination of endoscopy and biopsy. This study is to evaluate the maspin expression patterns as early diagnostic markers of malignancy in BE patients.

MATERIALS AND METHODS

Immunohistochemistry (IHC) staining was performed on 62 archival core biopsies from 35 patients, including BE without dysplasia (intestinal metaplasia, IM), BE with low grade dysplasia, BE with high grade dysplasia, carcinoma in situ, and well to poorly differentiated ECA/GEJ Aca (PD-ECA/GEJ Aca). The intensity and the subcellular distribution of immunoreactivity were evaluated microscopically. Statistical analysis was performed using the χ2 and Fisher exact tests.

RESULTS

The level of epithelial-specific tumor suppressor maspin protein inversely correlated with the progression from IM to PD-ECA/GEJ Aca. Lesions of each pathological grade could be divided into subtypes that exhibited distinct maspin subcellular distribution patterns, including nuclear only (Nuc), combined nuclear and cytoplasmic (Nuc+Cyt), cytoplasmic only (Cyt) and overall negligible (Neg). The Cyt subtype, which was minor in both IM and dysplasia (approximately 10%), was predominant in ECA/GEJ Aca as early as well-differentiated lesions (more than 50%: p = 0.0092). In comparison, nuclear staining of the tumor suppressor TP53 was heterogeneous in dysplasia, and did not correlate with the differentiation grades of ECA/GEJ Aca.

CONCLUSION

The Cyt subtype of maspin expression pattern in core biopsies of BE patients may serve as a molecular marker for early diagnosis of ECA/GEJ Aca.

The role of Tannerella forsythia and Porphyromonas gingivalis in pathogenesis of esophageal cancer

Tannerella forsythia and Porphyromonas gingivalis are anaerobic, Gram-negative bacterial species which have been implicated in periodontal diseases as a part of red complex of periodontal pathogens. Esophageal cancer is the eight most common cause of cancer deaths worldwide. Higher rates of esophageal cancer cases may be attributed to lifestyle factors such as: diet, obesity, alcohol and tobacco use. Moreover, the presence of oral P. gingivalis and T. forsythia has been found to be associated with an increased risk of esophageal cancer. Our review describes the role of P. gingivalis and T. forsythia in signaling pathways responsible for cancer development. It has been shown that T. forsythia may induce pro-inflammatory cytokines such as IL-1β and IL-6 by CD4 + T helper cells and TNF-α. Moreover, gingipain K produced by P. gingivalis, affects hosts immune system by degradation of immunoglobulins and complement system (C3 and C5 components). Discussed bacteria are responsible for overexpression of MMP-2, MMP-2 and GLUT transporters.