Molecular markers for Barrett's esophagus and its progression to cancer

p53 as Exemplar Next-Generation Immunohistochemical Marker: A Molecularly Informed, Pattern-Based Approach, Methodological Considerations, and Pan-Cancer Diagnostic Applications

This review is based on a webinar I presented for the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) in February 2022. It is intended that all ISIMM webinars will ultimately be published in AIMM as review articles. This work is also dedicated to Clive Taylor, who has deeply impacted my career. It presents a molecularly informed, pattern-based approach to p53 immunohistochemistry interpretation, methodological considerations (ie, antibody selection, optimization, validation, controls, and external quality assessment), and pan-cancer diagnostic applications, including those drawn from gastrointestinal, genitourinary, gynecological, neuroendocrine, hematologic, and neuropathology. It intends to prove the thesis statement that p53 is an exemplar next-generation immunohistochemical marker "born" ahead of its time.

A Consensus Diagnosis Utilizing Surface KI-67 Expression as an Ancillary Marker in Low-Grade Dysplasia Helps Identify Patients at High Risk of Progression to High-Grade Dysplasia and Esophaegal Adenocarcinoma

Esophageal adenocarcinoma (EAC) develops in a step-wise manner, from low-grade dysplasia (LGD) to high-grade dysplasia (HGD), and ultimately to invasive EAC. However, there remains diagnostic uncertainty about LGD and its risk of progression to HGD/EAC. The aim is to investigate the role of Ki-67, immune-histochemical marker of proliferation, surface expression in patients with confirmed LGD, and risk stratify progression to HGD/EAC. A retrospective cohort study was conducted. Patients with confirmed LGD and indefinite for dysplasia (IND), with a mean follow-up of ≥1 year, were included. Pathology specimens were stained for Ki-67 and analyzed for evidence of surface expression. Our results reveal that 29% of patients with confirmed LGD who stained positive with Ki-67 progressed to HGD/EAC as opposed to none (0%) of the patients who stained negative, a statistically significant result (P = 0.003). Similarly, specimens from patients with IND were stained and analyzed revealing a nonsignificant trend toward a higher rate of progression for Ki-67 positive cases versus Ki-67 negative, 30% versus 21%, respectively. Ki-67 expression by itself can identify patients with LGD at a high risk of progression.

Current state of prognostication, therapy and prospective innovations for Barrett's-related esophageal adenocarcinoma: a literature review

Objective

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), which has one of the lowest 5-year survival rates in oncology. The reasons for poor survival are twofold: the large majority of diagnoses are in advanced stages (~80%) and limited treatment options, with a deficit of biology-guided therapies. As a rapidly growing public health concern with poor prognosis, research into the molecular progression for BE and novel therapeutics for EAC currently has high clinical utility. Review of the literature reveals that innovative analysis of metaplastic progression from BE to EAC at a molecular level can shed light on the underlying transformative probabilities of BE into malignant pathologies and may impact current of future therapeutic modalities for management of these diseases.

Background

EAC is the fastest increasing cancer in the United States with a 600% increase over the past 25 years. This cancer arises from dysplastic tissue of BE, a complication of gastroesophageal reflux disease (GERD). Chronic acid and bile reflux in the distal esophagus initiates a metaplastic conversion of normal squamous epithelium to premalignant intestinalized columnar epithelium. Patients with BE have a 125-fold higher risk of cancer compared to the general population.

Methods

We critically reviewed the current status of BE monitoring, and subsequent therapeutic strategies being used in patients who have progressed to cancer. Also, new diagnostic tools and therapeutic candidates for BE-related EAC are discussed. Highly-targeted searches of databases containing recent original peer-reviewed papers were utilized for this review.

Conclusions

Novel and well-described biomarkers analyzed in the patient's diseased tissue will provide for more powerful diagnostics, but also possess the potential to develop strategies for personalized management and identify targets for intervention to either cease disease progression or treat BE and/or EAC. Since millions of Americans develop BE without progressing to cancer, there is a critical need to identify the small percentage of Barrett's patients who possess hallmarks of disease progression or carcinogenesis with novel screening techniques. Incorporation of such tools into standard screening protocols for BE surveillance and/or therapy would be critical to detect malignant transformations before clinically obvious cancer ever develops.

Neutrophil to lymphocyte ratio and risk of neoplastic progression in patients with Barrett's esophagus

BACKGROUND

Patient's with Barrett's esophagus (BE) are at risk of progression to esophageal adenocarcinoma (EAC). Neutrophil to lymphocyte ratio (NLR) was found to be a predictor of poor prognosis in patients with EAC; however, its performance in premalignant esophageal lesions is vague. We aimed to evaluate the utility of NLR as a predictor of histologic progression in patients with BE. METHODS : A prospective cohort of patients with proven BE in a tertiary referral center was retrospectively analyzed. All biopsies were reviewed by an expert gastrointestinal pathologist. The discriminatory capacity of NLR was evaluated by area under the receiver operating characteristic (AUC) curve analysis and Cox regression analysis.

RESULTS

324 patients (mean age 62.3 years, 241 [74.4 %] males) were included in the final analysis. Overall, 13 patients demonstrated histologic progression to neoplasia over a mean follow-up of 3.7 years (progression risk 1.0 % per year). The AUC of NLR for progression to high grade dysplasia (HGD) or EAC was 0.88 (95 % confidence interval [CI] 0.83 - 0.96), and baseline NLR was associated with a 3-fold increase of progression to HGD and EAC during follow-up (hazard ratio [HR] 3.2, 95 %CI 1.5 - 5.8; P < 0.001). Notably, in a subgroup analysis of patients with nondysplastic BE (NDBE) at presentation, NLR was also a risk factor for histologic progression (HR 2.4, 95 %CI 1.7 - 3.4; P < 0.001).

CONCLUSION

NLR predicted histologic progression in patients with BE. Patients with NDBE and NLR above 2.4 can be considered for specific surveillance programs with shorter intervals between sessions.

The modern management of Barrett's oesophagus and related neoplasia: role of pathology

Modern management of Barrett's oesophagus and related neoplasia essentially focuses upon surveillance to detect early low-risk neoplastic lesions and offering organ-preserving advanced endoscopic therapies, while traditional surgical treatments of oesophagectomy and lymph node clearance with or without chemoradiation are preserved only for high-risk and advanced carcinomas. With this evolution towards figless invasive therapy, the choice of therapy hinges upon the pathological assessment for risk stratifying patients into those with low risk for nodal metastasis who can continue with less invasive endoscopic therapies and others with high risk for nodal metastasis for which surgery or other forms of treatment are indicated. Detection and confirmation of neoplasia in the first instance depends upon endoscopic and pathological assessment. Endoscopic examination and biopsy sampling should be performed according to the recommended protocols, and endoscopic biopsy interpretation should be performed applying standard criteria using appropriate ancillary studies by histopathologists experienced in the pathology of Barrett's disease. Endoscopic resections (ERs) are both diagnostic and curative and should be performed by clinicians who are skilled with advanced endoscopic techniques. Proper preparation and handling of ERs are essential to assess histological parameters that dictate the curative nature of the procedure. Those parameters are adequacy of resection and risk of lymph node metastasis. The risk of lymph node metastasis is determined by depth invasion and presence of poor differentiation and lymphovascular invasion. Those adenocarcinomas with invasion up to muscularis mucosae (pT1a) and those with superficial submucosal invasion (pT1b) up to 500 µ with no poor differentiation and lymphovascular invasion and negative margins may be considered cured by endoscopic resections.

Is Malignant Potential of Barrett's Esophagus Predictable by Endoscopy Findings?

Given that endoscopic findings can be used to predict the potential of neoplastic progression in Barrett's esophagus (BE) cases, the detection rate of dysplastic Barrett's lesions may become higher even in laborious endoscopic surveillance because a special attention is consequently paid. However, endoscopic findings for effective detection of the risk of neoplastic progression to esophageal adenocarcinoma (EAC) have not been confirmed, though some typical appearances are suggestive. In the present review, endoscopic findings that can be used predict malignant potential to EAC in BE cases are discussed. Conventional results obtained with white light endoscopy, such as length of BE, presence of esophagitis, ulceration, hiatal hernia, and nodularity, are used as indicators of a higher risk of neoplastic progression. However, there are controversies in some of those findings. Absence of palisade vessels may be also a new candidate predictor, as that reveals degree of intense inflammation and of cyclooxygenase-2 protein expression with accelerated cellular proliferation. Furthermore, an open type of mucosal pattern and enriched stromal blood vessels, which can be observed by image-enhanced endoscopy, including narrow band imaging, have been confirmed as factors useful for prediction of neoplastic progression of BE because they indicate more frequent cyclooxygenase-2 protein expression along with accelerated cellular proliferation. Should the malignant potential of BE be shown predictable by these endoscopic findings, that would simplify methods used for an effective surveillance, because patients requiring careful monitoring would be more easily identified. Development in the near future of a comprehensive scoring system for BE based on clinical factors, biomarkers and endoscopic predictors is required.

Validation of a biomarker panel in Barrett's esophagus to predict progression to esophageal adenocarcinoma

In a prior study, baseline mutational load (ML) predicted progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) in Barrett's esophagus (BE) with an area under the curve (AUC) of 0.95. We aimed to validate the test characteristics of this predictive biomarker panel using crude DNA lysates in a larger well-characterized cohort. We performed a nested case-control study of BE patients from three tertiary referral centers in the Netherlands. Cases had baseline nondysplastic BE (NDBE) and developed HGD/EAC ≥ 2 years later. Controls were matched 2:1, had baseline NDBE, and no progression. Polymerase chain reaction (PCR)-based mutational analysis was performed on crude lysates from formalin-fixed, paraffin-embedded tissue. ML was calculated from loss of heterozygosity (LOH) and microsatellite instability (MSI) at 10 genomic loci. Receiver operator characteristic (ROC) curves were created to assess the diagnostic utility of various cutoffs of ML for progression. Of 159 subjects, 58 were progressors and 101 were nonprogressors, there was no difference in mean ML in preprogression tissue in progressors and nonprogressors (ML = 0.73 ± 0.69 vs. ML = 0.74 ± 0.61, P = 0.93). ROC curves showed poor discrimination of ML in predicting progression with AUC of 0.50 at ML ≥ 1. AUC did not vary with different ML cut-points. The utility of the ML to stratify BE patients for risk of progression was not confirmed in this study. The etiology for discrepancies between this and prior studies showing high predictiveness is likely due to the use of crude lysates in this study, but requires further investigation.

EBV相关性胃癌研究进展

胃癌细胞中存在Epstein-Barr病毒(Epstein-Barr virus, EBV)者被称为EBV相关性胃癌(Epstein-Barr virus-associated gastric carcinoma, EBVaGC). 近年来EBVaGC作为一种独特的分子亚型疾病逐渐被人们所认知, 全球胃癌患者中平均有10%者为EBVaGC. 本文对EBVaGC近年来在流行病学、临床病理特征、发病机制、治疗及预后等方面的研究进展作一综述. 但目前对EBVaGC的研究尚不明确, 且尚无临床诊疗规范与共识, 也带来了新的挑战和机遇.

Molecular Detection of Gastrointestinal Neoplasia: Innovations in Early Detection and Screening

Emerging molecular tools promise to extend the diagnostic reach of the endoscopist and open doors to population screening for gastrointestinal (GI) cancers. This review briefly addresses biological considerations in marker detection and types of markers, highlights examples of tools under development at each organ site, and appraises the possibility of universal GI cancer screening. The outlook is positive, but further technical refinement and rigorous clinical validation are needed before most of these new approaches are ready for clinical application.

Controlled bile acid exposure to oesophageal mucosa causes up-regulation of nuclear γ-H2AX possibly via iNOS induction

The results of the present study provide suggestion that not only acid reflux, but also non-acid reflux of bile may cause genotoxic stress. These aspects merit to be tested in wide spectrum of Barrett epithelial tissues.

Using an in vitro model in which flatmounts of oesophagus was periodically exposed to bile acids, we demonstrate, using multiple methods, that the bile acid receptor TGR5, inducible nitric oxide synthase (iNOS) and γ-histone family 2A variant (γ-H2AX) are up-regulated. This indicates that bile acids cause up-regulation of iNOS, which further causes genotoxic stress as evidenced by increase of the highly sensitive marker, phosphorylated histone. In vitro nitric oxide (NO) assays showed increased production of nitric acid in the oesophageal epithelium exposed to the bile acids. This increase was inhibited in the presence of the nonspecific iNOS inhibitor aminoguanidine (AG). Cumulatively, the results of the present study provide suggestion that not only acid reflux, but also non-acid reflux of bile may cause genotoxic stress. These aspects merit to be tested in wide spectrum of Barrett epithelial tissues.

ACG Clinical Guideline: Diagnosis and Management of Barrett's Esophagus

Barrett's esophagus (BE) is among the most common conditions encountered by the gastroenterologist. In this document, the American College of Gastroenterology updates its guidance for the best practices in caring for these patients. These guidelines continue to endorse screening of high-risk patients for BE; however, routine screening is limited to men with reflux symptoms and multiple other risk factors. Acknowledging recent data on the low risk of malignant progression in patients with nondysplastic BE, endoscopic surveillance intervals are attenuated in this population; patients with nondysplastic BE should undergo endoscopic surveillance no more frequently than every 3-5 years. Neither routine use of biomarker panels nor advanced endoscopic imaging techniques (beyond high-definition endoscopy) is recommended at this time. Endoscopic ablative therapy is recommended for patients with BE and high-grade dysplasia, as well as T1a esophageal adenocarcinoma. Based on recent level 1 evidence, endoscopic ablative therapy is also recommended for patients with BE and low-grade dysplasia, although endoscopic surveillance continues to be an acceptable alternative. Given the relatively common recurrence of BE after ablation, we suggest postablation endoscopic surveillance intervals. Although many of the recommendations provided are based on weak evidence or expert opinion, this document provides a pragmatic framework for the care of the patient with BE.

The Presence of Genetic Mutations at Key Loci Predicts Progression to Esophageal Adenocarcinoma in Barrett's Esophagus

OBJECTIVES

Risk stratification in Barrett's esophagus (BE) is challenging. We evaluated the ability of a panel of genetic markers to predict progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC).

METHODS

In this case-control study, we assessed a measure of genetic instability, the mutational load (ML), in predicting progression to HGD or EAC. Cases had nondysplastic BE or low-grade dysplasia (LGD) at baseline and developed HGD/EAC ≥1 year later. Controls were matched 2:1, had nondysplastic BE or LGD, and no progression at follow-up. Formalin-fixed, paraffin-embedded tissue was microdissected for the epithelium. Loss of heterozygosity (LOH) and microsatellite instability (MSI) were assessed. ML was calculated from derangements in 10 genomic loci. High-clonality LOH mutations were assigned a value of 1, low-clonality mutations were assigned a value of 0.5, and MSI 0.75 at the first loci, and 0.5 for additional loci. These values were summed to the ML. Receiver operator characteristic (ROC) curves were created.

RESULTS

There were 69 patients (46 controls and 23 cases). Groups were similar in age, follow-up time, baseline histology, and the number of microdissected targets. Mean ML in pre-progression biopsies was higher in cases (2.21) than in controls (0.42; P<0.0001). Sensitivity was 100% at ML ≥0.5 and specificity was 96% at ML ≥1.5. Accuracy was highest at 89.9% for ML ≥1. ROC curves for ML ≥1 demonstrated an area under the curve (AUC) of 0.95.

CONCLUSIONS

ML in pre-progression BE tissue predicts progression to HGD or EAC. Although further validation is necessary, ML may have utility as a biomarker in endoscopic surveillance of BE.

A cross sectional study of p504s, CD133, and Twist expression in the esophageal metaplasia dysplasia adenocarcinoma sequence

The incidence of esophageal adenocarcinoma has increased dramatically over recent years and Barrett's esophagus is considered the most established risk factor for its development. Endoscopic surveillance of Barrett's esophagus is therefore recommended but hinges on histological interpretation of randomly taken biopsies which is poorly reproducible. The use of biomarkers presents an opportunity to improve our ability to risk-stratify these patients.We examined three biomarkers namely p504s, CD133, and Twist in the setting of Barrett's esophagus, low-grade dysplasia, and esophageal adenocarcinoma to evaluate differential expression between benign, dysplastic, and malignant Barrett's tissue in an exploratory cross-sectional study. Twenty-five cases each of Barrett's esophagus, low-grade dysplasia, and esophageal adenocarcinoma were included along-with 25 cases of esophagectomy resections for Barrett's adenocarcinoma. The biomarkers were immunostained on automated Ventana(®) immunostainer. The biopsies were assessed for biomarker expression by two independent observers. Granular cytoplasmic staining of p504s was observed in dysplastic Barrett's biopsies and esophageal adenocarcinoma but not in Barrett's esophagus. Apical and membranous CD133 expression was also observed in dysplastic Barrett's and esophageal adenocarcinoma. Nuclear Twist expression was seen predominantly in stromal cells. There was increased p504s expression in dysplastic Barrett's esophagus and esophageal adenocarcinoma compared with controls. CD133 expression was detected for the first time in esophageal adenocarcinoma and dysplastic Barrett's esophagus. Twist expression was not convincing enough to be labeled as Barrett's biomarker. p504s and CD133 have the potential to differentiate benign from malignant Barrett's tissue in this exploratory study. Their validity should be established in prospective longitudinal studies.

Barrett's oesophagus: frequency and prediction of dysplasia and cancer

The incidence of oesophageal adenocarcinoma is continuing to increase at an alarming rate in the Western world today. Barrett's oesophagus is a clearly recognized risk factor for the development of oesophageal adenocarcinoma, but the overwhelming majority of patients with Barrett's oesophagus will never develop oesophageal cancer. A number of endoscopic, histologic and epidemiologic risk factors identify Barrett's oesophagus patients at increased risk for progression to high-grade dysplasia and oesophageal adenocarcinoma. Endoscopic factors include segment length, mucosal abnormalities as seemingly trivial as oesophagitis and the 12 to 6 o'clock hemisphere of the oesophagus. Both intestinal metaplasia and low grade dysplasia, the latter only if confirmed by a pathologist with expertise in Barrett's oesophagus pathologic interpretation are the histologic risk factors for progression. Epidemiologic risk factors include ageing, male gender, obesity, and smoking. Factors that may protect against the development of adenocarcinoma include a diet rich in fruits and vegetables, and the use of proton pump inhibitors, aspirin/NSAIDs and statins.

Genomic assays for Epstein-Barr virus-positive gastric adenocarcinoma

A small set of gastric adenocarcinomas (9%) harbor Epstein–Barr virus (EBV) DNA within malignant cells, and the virus is not an innocent bystander but rather is intimately linked to pathogenesis and tumor maintenance. Evidence comes from unique genomic features of host DNA, mRNA, microRNA and CpG methylation profiles as revealed by recent comprehensive genomic analysis by The Cancer Genome Atlas Network. Their data show that gastric cancer is not one disease but rather comprises four major classes: EBV-positive, microsatellite instability (MSI), genomically stable and chromosome instability. The EBV-positive class has even more marked CpG methylation than does the MSI class, and viral cancers have a unique pattern of methylation linked to the downregulation of CDKN2A (p16) but not MLH1. EBV-positive cancers often have mutated PIK3CA and ARID1A and an amplified 9p24.1 locus linked to overexpression of JAK2, CD274 (PD-L1) and PDCD1LG2 (PD-L2). Multiple noncoding viral RNAs are highly expressed. Patients who fail standard therapy may qualify for enrollment in clinical trials targeting cancer-related human gene pathways or promoting destruction of infected cells through lytic induction of EBV genes. Genomic tests such as the GastroGenus Gastric Cancer Classifier are available to identify actionable variants in formalin-fixed cancer tissue of affected patients.

Recent advances in molecular imaging of premalignant gastrointestinal lesions and future application for early detection of barrett esophagus

Recent advances in optical molecular imaging allow identification of morphologic and biochemical changes in tissues associated with gastrointestinal (GI) premalignant lesions earlier and in real-time. This focused review series introduces high-resolution imaging modalities that are being evaluated preclinically and clinically for the detection of early GI cancers, especially Barrett esophagus and esophageal adenocarcinoma. Although narrow band imaging, autofluorescence imaging, and chromoendoscopy are currently applied for this purpose in the clinic, further adoptions of probe-based confocal laser endomicroscopy, high-resolution microendoscopy, optical coherence tomography, and metabolomic imaging, as well as imaging mass spectrometry, will lead to detection at the earliest and will guide predictions of the clinical course in the near future in a manner that is beyond current advancements in optical imaging. In this review article, the readers will be introduced to sufficient information regarding this matter with which to enjoy this new era of high technology and to confront science in the field of molecular medical imaging.

Cost-effectiveness of Barrett's oesophagus screening and surveillance

Endoscopic screening and surveillance of patients with Barrett's oesophagus to detect oesophageal cancer at earlier stages is contentious. As a consequence, their cost-effectiveness is also debatable. Current health economic evidence shows mixed results for demonstrating their value, mainly due to varied assumptions around progression rates to cancer, quality of life and treatment pathways. No randomized controlled trial exists to definitively support the efficacy of surveillance programs and one is unlikely to be undertaken. Contemporary treatment, cost and epidemiological data to contribute to cost-effectiveness analyses are needed. Risk assessment to stratify patients at low- or high-risk of developing cancer should improve cost-effectiveness outcomes as higher gains will be seen for those at higher risk, and medical resource use will be avoided in those at lower risk. Rapidly changing technologies for imaging, biomarker testing and less-invasive endoscopic treatments also promise to lower health system costs and avoid adverse events in patients.

Research advances in esophageal diseases: bench to bedside

Over the last year, significant steps have been made toward understanding the pathogenesis of esophageal diseases and translating this knowledge to clinical practice. Gastroesophageal reflux disease (GERD) is the most common outpatient diagnosis in gastroenterology and has a high prevalence in the general population. As many as 40% of patients with GERD have incomplete response to medical therapy, and the pathophysiological mechanisms underlying lack of response are now better understood. Novel medical and minimally invasive interventions are available to optimize management of GERD. Esophageal cancer, regardless of the histological subtype, has among the worst survival statistics among all malignancies. Taking advantage of technological advances in genome sequencing, the mutational spectra in esophageal cancer are now emerging, offering novel avenues for targeted therapies. Early diagnosis is another strand for improving survival. While genome-wide association studies are providing insights into genetic susceptibility, novel approaches to early detection of cancer are being devised through the use of biomarkers applied to esophageal samples and as part of imaging technologies. Dysmotility and eosinophilic esophagitis are the differential diagnoses in patients with dysphagia. New pathophysiological classifications have improved the management of motility disorders. Meanwhile, exciting progress has been made in the endoscopic management of these conditions. Eosinophilic esophagitis is still a relatively new entity, and the pathogenesis remains poorly understood. However, it is now clear that an allergic reaction to food plays an important role, and dietary interventions as well as biologic agents to block the inflammatory cascade are novel, promising fields of clinical research.