Evaluation of microvascular density in Barrett's associated neoplasia

Using digital pathology to analyze the murine cerebrovasculature

Research on the cerebrovasculature may provide insights into brain health and disease. Immunohistochemical staining is one way to visualize blood vessels, and digital pathology has the potential to revolutionize the measurement of blood vessel parameters. These tools provide opportunities for translational mouse model research. However, mouse brain tissue presents a formidable set of technical challenges, including potentially high background staining and cross-reactivity of endogenous IgG. Formalin-fixed paraffin-embedded (FFPE) and fixed frozen sections, both of which are widely used, may require different methods. In this study, we optimized blood vessel staining in mouse brain tissue, testing both FFPE and frozen fixed sections. A panel of immunohistochemical blood vessel markers were tested (including CD31, CD34, collagen IV, DP71, and VWF), to evaluate their suitability for digital pathological analysis. Collagen IV provided the best immunostaining results in both FFPE and frozen fixed murine brain sections, with highly-specific staining of large and small blood vessels and low background staining. Subsequent analysis of collagen IV-stained sections showed region and sex-specific differences in vessel density and vessel wall thickness. We conclude that digital pathology provides a useful tool for relatively unbiased analysis of the murine cerebrovasculature, provided proper protein markers are used.

Development of Advanced Imaging and Molecular Imaging for Barrett's Neoplasia

Barrett esophagus (BE) is a precursor to a life-threatening esophageal adenocarcinoma (EAC). Surveillance endoscopy with random biopsies is recommended for early intervention against EAC, but its adherence in the clinical setting is poor. Dysplastic lesions with flat architecture and patchy distribution in BE are hardly detected by high-resolution endoscopy, and the surveillance protocol entails issues of time and labor and suboptimal interobserver agreement for diagnosing dysplasia. Therefore, the development of advanced imaging technologies is necessary for Barrett's surveillance. Recently, non-endoscopic or endoscopic technologies, such as cytosponge, endocytoscopy, confocal laser endomicroscopy, autofluorescence imaging, and optical coherence tomography/volumetric laser endomicroscopy, were developed, but most of them are not clinically available due to the limited view field, expense of the equipment, and significant time for the learning curve. Another strategy is focused on the development of molecular biomarkers, which are also not ready to use. However, a combination of advanced imaging techniques together with specific biomarkers is expected to identify morphological abnormalities and biological disorders at an early stage in the surveillance. Here, we review recent developments in advanced imaging and molecular imaging for Barrett's neoplasia. Further developments in multiple biomarker panels specific for Barrett's HGD/EAC include wide-field imaging systems for targeting 'red flags', a high-resolution imaging system for optical biopsy, and a computer-aided diagnosis system with artificial intelligence, all of which enable a real-time and accurate diagnosis of dysplastic BE in Barrett's surveillance and provide information for precision medicine.

Spectral Endoscopy Enhances Contrast for Neoplasia in Surveillance of Barrett's Esophagus

Early detection of esophageal neoplasia enables curative endoscopic therapy, but the current diagnostic standard of care has low sensitivity because early neoplasia is often inconspicuous with conventional white-light endoscopy. Here, we hypothesized that spectral endoscopy could enhance contrast for neoplasia in surveillance of patients with Barrett's esophagus. A custom spectral endoscope was deployed in a pilot clinical study of 20 patients to capture 715 in vivo tissue spectra matched with gold standard diagnosis from histopathology. Spectral endoscopy was sensitive to changes in neovascularization during the progression of disease; both non-dysplastic and neoplastic Barrett's esophagus showed higher blood volume relative to healthy squamous tissue (P = 0.001 and 0.02, respectively), and vessel radius appeared larger in neoplasia relative to non-dysplastic Barrett's esophagus (P = 0.06). We further developed a deep learning algorithm capable of classifying spectra of neoplasia versus non-dysplastic Barrett's esophagus with high accuracy (84.8% accuracy, 83.7% sensitivity, 85.5% specificity, 78.3% positive predictive value, and 89.4% negative predictive value). Exploiting the newly acquired library of labeled spectra to model custom color filter sets identified a potential 12-fold enhancement in contrast between neoplasia and non-dysplastic Barrett's esophagus using application-specific color filters compared with standard-of-care white-light imaging (perceptible color difference = 32.4 and 2.7, respectively). This work demonstrates the potential of endoscopic spectral imaging to extract vascular properties in Barrett's esophagus, to classify disease stages using deep learning, and to enable high-contrast endoscopy. SIGNIFICANCE: The results of this pilot first-in-human clinical trial demonstrate the potential of spectral endoscopy to reveal disease-associated vascular changes and to provide high-contrast delineation of neoplasia in the esophagus. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/12/3415/F1.large.jpg.

Expression and clinical significance of aquaporin-1, vascular endothelial growth factor and microvessel density in gastric cancer

To investigate the expression and clinical significance of aquaporin-1 (AQP1), vascular endothelial growth factor (VEGF) and microvessel density (MVD) in gastric cancer.A total of 79 gastric cancer patients who were admitted into Beijing Chao-Yang Hospital from January, 2018 to December, 2019 were involved in this study. Tumor specimens and para-cancerous normal tissues (> 2 cm away from the tumor) of all the enrolled patients were collected. Immunohistochemistry were performed to identify the expression of AQP1, VEGF, and MVD and the correlation between AQP1, VEGF, MVD, and clinicopathological parameters was analyzed.The expression of AQP1, VEGF and MVD in gastric cancer tissue was increased significantly compared with those in para-cancerous tissue (P < .05). AQP1, VEGF, and MVD were closely correlated with gastric cancer differentiation, lymph node metastasis, vascular tumor thrombosis and clinical stage (P < .05). Spearman correlation analysis showed that AQP1 was positively associated with VEGF expression (r = 0.497, P < .05). MVD was enhanced in VEGF or AQP1 positive cancer tissues compared with that in VEGF or AQP1 negative tissue (P < .05).Synergistic effect among AQP1, VEGF, and MVD is involved in occurrence and development of gastric cancer.

Correlation of narrow band imaging vascular patterns with immunohistological microvessel density in vocal fold lesions

INTRODUCTION

The microarchitecture of the mucosal and submucosal vessels is crucial for diagnosis of vocal fold lesions. Neo-angiogenesis is a confirmed biological parameter that implicates progression and metastasis in laryngeal cancer.

OBJECTIVE

This study investigates the correlation between vascular pattern classifications by narrow band imaging and immunohistological microvessel density in different types of intraepithelial vocal fold lesions.

METHODS

Analysis of immunohistological microvessel density using CD31 and CD34 antibodies was performed in 77 lesions including: 20 non-dysplastic lesions, 20 with low-grade dysplasia, 17 with high-grade dysplasia and 20 invasive cancers. The evaluation of vascular patterns with narrow band imaging according to the Ni classification and European Laryngological Society guidelines was performed prior to surgical resection.

RESULTS

The mean value of CD31 microvessel density was the highest for Ni Type IV lesions (20.55), whereas for the longitudinal and perpendicular patterns according to the European Laryngological Society classification it was 12.50 and 19.45 respectively. The highest mean value of microvessel density with CD 34 was identified in Ni Type Va (35.43) lesions and in the longitudinal and perpendicular patterns according to the European Laryngological Society classification was 15.12 and 30.40 respectively.

CONCLUSIONS

The microvascular morphological changes of intraepithelial laryngeal lesions observed under narrow band imaging endoscopy are positively correlated with angiogenesis indexes of immunohistological evaluation.

Microvascular density and hypoxia-inducible factor in intraepithelial vocal fold lesions

OBJECTIVE

The promotion of neovascularisation is a crucial aspect of carcinogenesis. The study evaluates the microvascular density (MVD) and expression of hypoxia-induced factor (HIF-1α) in hypertrophic vocal fold (VF) lesions of different histopathological states including non-dysplastic, low-grade, high-grade dysplasia and invasive glottic cancer.

MATERIALS AND METHODS

Histological specimens collected from patients diagnosed and treated in a single centre with different histological grades were immunohistochemically stained with CD31, CD34 and HIF-1α. Of the total number of 77 analysed VF specimens, 20 were non-dysplastic, 20 had low-grade dysplasia, 17 high-grade dysplasia and 20 were invasive cancers.

RESULTS

The highest mean value for MVD evaluated with expression of CD31 (MVD CD31) was 21.23 ± 14.46 and identified in the low-grade dysplasia group. The average MVD CD31 was 13.74 ± 5.56 and 20.11 ± 9.28 in the high-grade dysplasia and invasive cancer group, respectively. The highest MVD evaluated with CD34 (MVD CD34) was revealed for invasive cancer 35.64 ± 17.21. The MVD CD34 was higher for low-grade than in high-grade dysplasia (25.87 ± 12.30 vs 24.65 ± 15.92, respectively). The expression of HIF-1α was strong or very strong in 60% of non-dysplastic lesions, 100% of low-grade dysplasia cases, 53% of high-grade dysplasia cases and 50% of invasive cancer cases. The comparison of MVD CD31 with MVD CD34 revealed a strong positive correlation (ρ value 0.727). The comparison of both MVD CD31 and MVD CD34 with HIF-1α resulted in no linear relationship (ρ value of 0.143 and 0.165, respectively).

CONCLUSION

The stage of low-grade dysplasia in intraepithelial vocal fold lesions is related to significant advancement of angiogenesis together with the highest hypoxia level.

Biomarkers of Barrett's Esophagus: From the Laboratory to Clinical Practice

The currently recommended approach to managing cancer risk for patients with Barrett's esophagus is endoscopic surveillance including a biopsy protocol to sample the esophageal tissue randomly to detect dysplasia. However, there are numerous limitations in this practice that rely on the histopathological grading of dysplasia alone to make clinical decisions. The availability of in silico models demonstrating the potential cost-effectiveness of biomarker-based stratification has increased interest in finding a clinically relevant "Barrett's biomarker." The success of endoscopic eradication therapy in preventing neoplastic progression of dysplastic Barrett's esophagus has promoted the desire to stratify non-dysplastic Barrett's esophagus to those with "high risk" that may benefit from endotherapy. Furthermore, on the other end of the spectrum, there is interest in searching for a "low risk" marker that may identify those that would not likely benefit from endoscopy screening or surveillance. This review highlights recent data from the genomics (r)evolution revealing new genetic biomarkers of susceptibility to the development of Barrett's esophagus and novel pathways for its neoplastic progression, addresses the development of new modes of tissue sampling and imaging to detect early neoplasia in Barrett's esophagus, and discusses current progress in moving biomarkers from the laboratory into clinical practice in the era of precision medicine.

Microvascular fractal dimension predicts prognosis and response to chemotherapy in glioblastoma: an automatic image analysis study

The microvascular profile has been included in the WHO glioma grading criteria. Nevertheless, microvessels in gliomas of the same WHO grade, e.g., WHO IV glioblastoma (GBM), exhibit heterogeneous and polymorphic morphology, whose possible clinical significance remains to be determined. In this study, we employed a fractal geometry-derived parameter, microvascular fractal dimension (mvFD), to quantify microvessel complexity and developed a home-made macro in Image J software to automatically determine mvFD from the microvessel-stained immunohistochemical images of GBM. We found that mvFD effectively quantified the morphological complexity of GBM microvasculature. Furthermore, high mvFD favored the survival of GBM patients as an independent prognostic indicator and predicted a better response to chemotherapy of GBM patients. When investigating the underlying relations between mvFD and tumor growth by deploying Ki67/mvFD as an index for microvasculature-normalized tumor proliferation, we discovered an inverse correlation between mvFD and Ki67/mvFD. Furthermore, mvFD inversely correlated with the expressions of a glycolytic marker, LDHA, which indicated poor prognosis of GBM patients. Conclusively, we developed an automatic approach for mvFD measurement, and demonstrated that mvFD could predict the prognosis and response to chemotherapy of GBM patients.

Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy

Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P < 0.05). The correlation coefficients between vascular density determined by two endoscopists were 0.86 and 0.81 in cancerous and noncancerous areas, respectively. Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of vascular density was 0.895 (95% CI, 0.804-0.986). For this ROC curve, sensitivity was 78.3% and specificity was 87.0% when the cutoff value of vascular density was 26 vessels/mm2. NBI magnification confirmed significant increases in vascular density in cancerous areas compared with noncancerous areas in esophageal squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high.

Endoscopic optical coherence tomography angiography microvascular features associated with dysplasia in Barrett's esophagus (with video)

BACKGROUND AND AIMS

Angiogenesis is associated with neoplastic progression of Barrett's esophagus (BE). Volumetric optical coherence tomography angiography (OCTA) visualizes subsurface microvasculature without exogenous contrast agents. We investigated the association of OCTA microvascular features with low-grade dysplasia (LGD) and high-grade dysplasia (HGD).

METHODS

Fifty-two patients undergoing BE surveillance or endoscopic eradication therapies for dysplasia were imaged using volumetric OCTA and corresponding histologic diagnoses wre obtained to yield 97 data sets (nondysplastic BE [NDBE], 74; LGD, 10; HGD, 13). After evaluating OCTA image quality, 54 datasets (NDBE, 35; LGD, 8; HGD, 11) from 32 patients were used to develop a training and reading protocol. The association of abnormal vessel branching and heterogeneous vessel size with LGD/HGD and a regular honeycomb vessel pattern with NDBE were investigated.

RESULTS

Blinded OCTA reading of 41 OCTA datasets (NDBE, 27; LGD, 7; HGD, 7) was performed by readers with various levels of OCT/OCTA experience including 3 OCT trainees, 1 gastroenterologist, and 2 gastroenterology fellows. Among the 6 readers, OCTA features of abnormal vessel branching and heterogeneous vessel size had an overall 94% sensitivity (95% CI, 89-99) and 69% specificity (95% CI, 62-76) for differentiating LGD/HGD versus NDBE with a mean reading time of 45 seconds per data set and moderate (kappa = .58) interobserver agreement.

CONCLUSIONS

Volumetric en face OCTA imaging enables rapid examination of depth resolved microvascular features with near-microscopic resolution. OCTA can visualize microvascular features associated with LGD/HGD with high accuracy, which motivates new technologic advances and future studies investigating the diagnostic performance of OCTA.

Comparative diagnostic performance of volumetric laser endomicroscopy and confocal laser endomicroscopy in the detection of dysplasia associated with Barrett's esophagus

BACKGROUND AND AIMS

Probe-based confocal laser endomicroscopy (pCLE) and volumetric laser endomicroscopy (VLE) (also known as frequency domain optical coherence tomography) are advanced endoscopic imaging modalities that may be useful in the diagnosis of dysplasia associated with Barrett's esophagus (BE). We performed pCLE examination in ex-vivo EMR specimens and compared the diagnostic performance of using the current VLE scoring index (previously established as OCT-SI) and a novel VLE diagnostic algorithm (VLE-DA) for the detection of dysplasia.

METHODS

A total of 27 patients with BE enrolled in a surveillance program at a tertiary-care center underwent 50 clinically indicated EMRs that were imaged with VLE and pCLE and classified into neoplastic (N = 34; high-grade dysplasia, intramucosal adenocarcinoma) and nonneoplastic (N = 16; low-grade dysplasia, nondysplastic BE), based on histology. Image datasets (VLE, N = 50; pCLE, N = 50) were rated by 3 gastroenterologists trained in the established diagnostic criteria for each imaging modality as well as a new diagnostic algorithm for VLE derived from a training set that demonstrated association of specific VLE features with neoplasia. Sensitivity, specificity, and diagnostic accuracy were assessed for each imaging modality and diagnostic criteria.

RESULTS

The sensitivity, specificity, and diagnostic accuracy of pCLE for detection of BE dysplasia was 76% (95% confidence interval [CI], 59-88), 79% (95% CI, 53-92), and 77% (95% CI, 72-82), respectively. The optimal diagnostic performance of OCT-SI showed a sensitivity of 70% (95% CI, 52-84), specificity of 60% (95% CI, 36-79), and diagnostic accuracy of 67%; (95% CI, 58-78). The use of the novel VLE-DA showed a sensitivity of 86% (95% CI, 69-96), specificity of 88% (95% CI, 60-99), and diagnostic accuracy of 87% (95% CI, 86-88). The diagnostic accuracy of using the new VLE-DA criteria was significantly superior to the current OCT-SI (P < .01).

CONCLUSION

The use of a new VLE-DA showed enhanced diagnostic performance for detecting BE dysplasia ex vivo compared with the current OCT-SI. Further validation of this algorithm in vivo is warranted.

Simplified classification of capillary pattern in Barrett esophagus using magnifying endoscopy with narrow band imaging: implications for malignant potential and interobserver agreement

The classification of Barrett esophagus (BE) using magnifying endoscopy with narrow band imaging (ME-NBI) is not widely used in clinical settings because of its complexity. To establish a new simplified available classification using ME-NBI.We conducted a cross-sectional study in a single-referral center. One hundred eight consecutive patients with BE using ME-NBI and crystal violet (CV) chromoendoscopy, and histological findings were enrolled. BE areas observed by ME-NBI were classified as type I or II on the basis of capillary pattern (CP), and as closed or open type on the basis of a mucosal pit pattern using CV chromoendoscopy; then, biopsy samples were obtained. We evaluated the relation between CP and pit pattern, expression of the factors with malignant potential, percentage of microvascular density, and interobserver agreement.One hundred thirty lesions from 91 patients were analyzed. Type II CP had more open type pit pattern areas and significantly greater microvascular density than type I. The presence of dysplasia, specialized intestinal metaplasia, expressions of COX-2, CDX2, and CD34, and PCNA index were significantly higher in type II, whereas the multivariate analysis showed that type II was the best predictor for the presence of dysplasia (OR 11.14), CD34 expression (OR 3.60), and PCNA (OR 3.29). Interobserver agreement for this classification was substantial (κ = 0.66).A simplified CP classification based on observation with ME-NBI is presented. Our results indicate that the classification may be useful for surveillance of BE with high malignant potential.

Ischemic heart disease, factor predisposing to Barrett's adenocarcinoma: A case control study

AIM

To define the significance of ischemic heart disease (IHD) (stable angina to infarction) co-existance in Barrett esophagus (BE) patients and patients with esophageal adenocarcinoma (AdE).

METHODS

All BE/AdE patients in Blackpool-Wyre-Fylde area and Trikala prefecture identified from medical records. Patient clinical details were obtained from hospital and General Practitioner records. Additional information was gathered from validated questionnaire.

RESULTS

Forty (33%) AdE and 83 (19%) BE patients had IHD (P = 0.002). Eighteen (15%) AdE and 34 (8%) BE patients had suffered a myocardial infarction (P = 0.03). Three (3%) AdE and 7 (2%) BE patients had severe heart failure (P = 0.82). Thirty-nine (47%) BE with IHD and 8 (20%) AdE patients with IHD consumed aspirin daily (P = 0.004). Seventh-seven (93%) BE patients with IHD and 36 (90%) AdE patients with IHD were on statins (P = 0.86). Logistic regression analysis: AdE was more frequent in the elderly, with long term reflux, long BE and concurrent IHD (odds ratio: 2.086, P = 0.001) not consuming statins. Eighteen (22%) BE patients with IHD [16 (84%) with myocardial infarction] vs 33 (10%) without IHD died from non-neoplastic causes within 24 mo from BE diagnosis (P = 0.005).

CONCLUSION

IHD is more prevalent in AdE than BE patients. Increased prevalence of AdE is related with the presence of myocardial infarction but not severe heart failure, possibly because patients with BE and severe IHD have low life expectancy.