pCLE detects mucosal neoplastic vascular pattern in gastric linitis plastica

Linitis plastica (LP) is a very aggressive and rare carcinoma with a scirrhous stroma that affects the submucosal and muscular layers of the stomach even without mucosal alterations. Lack of timely diagnosis is a crucial problem related to its prognosis and treatment. In this study, we investigated the LP-associated vascular pattern as a possible means to improve the diagnosis of these patients. During standard endoscopy, mucosal architecture, tortuosity and enlargement of vessels, as well as the presence of vascular leakage and efficiency of the blood flow were assessed in six LP patients using probe-based Confocal Laser Endomicroscopy (pCLE). In all LP patients, we detected abnormal changes in vasculature. The aberrant features of the vascular network were common to all LP patients examined and consisted of vessel enlargement, tortuosity, and leakage associated with the affected submucosal layer. This is the first study to highlight the presence of marked vascularization associated with LP, characterized by the presence of abnormal and non-functional vessels, similar to what is observed in neoplastic tissues. Therefore, the analysis of LP by pCLE may provide a new endoscopic approach and strategy to better define these patients

Endomicroscopy and Cancer: A New Approach to the Visualization of Neoangiogenesis

Probe-based Confocal Laser Endomicroscopy (pCLE) is a novel imaging technique for gastrointestinal endoscopy providing in vivo microscopy at subcellular resolution. It offers the possibility to analyze neoangiogenesis and vessel density in vivo. Angiogenetic switch is essential in cancer progression. Aim of the paper was to review the use of this imaging tool to analyze colorectal and gastric cancers vascularization in vivo. The aim is to provide the possibility of combining diagnostic evidences with vascularization and molecular profile to evaluate the efficacy of an antiangiogenic treatment in association with conventional therapy. pCLE can be considered a revolutionary method for real-time assessment of changes in vascularization pattern in this tumors and it may open the possibility to address the use of anti-angiogenic therapy in order to improve the outcome of the treatment

Colorectal cancer development is affected by the ECM molecule EMILIN-2 hinging on macrophage polarization via the TLR-4/MyD88 pathway

Background Colorectal cancer is one of the most frequent and deadly tumors. Among the key regulators of CRC growth and progression, the microenvironment has emerged as a crucial player and as a possible route for the development of new therapeutic opportunities. More specifically, the extracellular matrix acts directly on cancer cells and indirectly affecting the behavior of stromal and inflammatory cells, as well as the bioavailability of growth factors. Among the ECM molecules, EMILIN-2 is frequently down-regulated by methylation in CRC and the purpose of this study was to verify the impact of EMILIN-2 loss in CRC development and its possible value as a prognostic biomarker. Methods The AOM/DSS CRC protocol was applied to Emilin-2 null and wild type mice. Tumor development was monitored by endoscopy, the molecular analyses performed by IHC, IF and WB and the immune subpopulations characterized by flow cytometry. Ex vivo cultures of monocyte/macrophages from the murine models were used to verify the molecular pathways. Publicly available datasets were exploited to determine the CRC patients' expression profile; Spearman's correlation analyses and Cox regression were applied to evaluate the association with the inflammatory response; the clinical outcome was predicted by Kaplan-Meier survival curves. Pearson correlation analyses were also applied to a cohort of patients enrolled in our Institute. Results In preclinical settings, loss of EMILIN-2 associated with an increased number of tumor lesions upon AOM/DSS treatment. In addition, in the early stages of the disease, the Emilin-2 knockout mice displayed a myeloid-derived suppressor cells-rich infiltrate. Instead, in the late stages, lack of EMILIN-2 associated with a decreased number of M1 macrophages, resulting in a higher percentage of the tumor-promoting M2 macrophages. Mechanistically, EMILIN-2 triggered the activation of the Toll-like Receptor 4/MyD88/NF-kappa B pathway, instrumental for the polarization of macrophages towards the M1 phenotype. Accordingly, dataset and immunofluorescence analyses indicated that low EMILIN-2 expression levels correlated with an increased M2/M1 ratio and with poor CRC patients' prognosis. Conclusions These novel results indicate that EMILIN-2 is a key regulator of the tumor-associated inflammatory environment and may represent a promising prognostic biomarker for CRC patients

Classification of Colon Polyps and Risk of Neoplastic Progression

Colorectal polyps are small clumps of cells and they are classified on the basis of their histological characteristics. Until recently, they have been divided into two major groups: neoplastic and non-neoplastic mucosal polyps. Adenomatous polyps contain epithelial neoplasia and their size and histology correlate with the risk of progression to carcinoma. Non-neoplastic polyps, instead, can be divided into several distinct and unrelated categories including hyperplastic, mucosal, juvenile, Peutz-Jeghers, and inflammatory. Adenomas are recognized as the precursor lesions for colorectal carcinoma and recently also some hyperplastic lesions, with serrated morphology, have been reported to display a significant risk of neoplastic progression through the so-called serrated pathway. The sequence adenoma-carcinoma is caused by different molecular pathways. The most frequent are those of chromosomal instability pathway; the microsatellite instability pathway; the serrated pathway. Molecular complexity can explain the morphological heterogeneity and the timing of neoplastic progression

Probe-based confocal laser endomicroscopy (pCLE) is a suitable method for extrapulmonary high grade neuroendocrine rectal carcinoma (HGNEC) evaluation

The potential role of the probe-based confocal laser endomicroscopy (pCLE) has been analyzed in different pathologic conditions of the gastrointestinal tract. Here, we analyzed a case of extrapulmonary high grade neuroendocrine rectal carcinoma (HGNEC) using, for the first time, the pCLE system. A 72-year old man was diagnosed with an 8 cm diameter rectal HGNEC by standard colonoscopy integrated with the pCLE system. The diagnosis of neuroendocrine carcinoma was confirmed by immunohistochemical analyses. By using the pCLE system, we well defined and resolved vascular structures and mucosal architecture. An altered mucosal pattern and vascular defects, peculiar for HGNEC, were observed at high magnification, allowing the identification of a pattern which was quite different from that observed in poorly differentiated adenocarcinomas (PDA) where tissues appear darker, very irregular, even if glandular structures can still be recognized. This underlines the usefulness of pCLE in discriminating HGNECs from PDAs. In conclusion, pCLE could represent a valid and helpful method for in vivo HGNEC diagnosis, allowing prompt and careful management of the patient

The Probe Based Confocal Laser Endomicroscopy (pCLE) in Locally Advanced Gastric Cancer: A Powerful Technique for Real-Time Analysis of Vasculature

Probe based confocal laser endomicroscopy (pCLE) is an advanced technique which provides imaging of gastrointestinal mucosa at subcellular resolution and, importantly, a valid tool for the evaluation of microvasculature during endoscopic examination. In order to assess intratumoral vascularization and the efficiency of blood flow in locally advanced gastric cancer, we examined 57 patients through pCLE imaging. The vascular alterations in gastric cancer were mainly characterized by leakage and by the presence of tortuous and large size vessels. Defects in blood flow were detected very rarely. No association between the angiogenic score and the gastric tumor site or histological type was observed. Interestingly, no correlation was also found with the tumor grading indicating that the vascular angiogenic anomalies in gastric cancer represent an early pathological event to be observed and detected. The majority of patients displayed unchanged vascular alterations following neoadjuvant chemotherapy and this positively correlated with stable or progressive disease, suggesting that an unaltered angiogenic score could per se be indicative of poor therapeutic efficacy. Different vascular parameters were evaluated by immunofluorescence using bioptic samples and the vessel density did not correlate with clinical staging, site or histologic type. Interestingly, only CD105, Multimerin-2 and GLUT1 were able to discriminate normal from tumoral gastric mucosa. Taken together, these findings indicate that functional and structural angiogenic parameters characteristic of tumor blood network were fully detectable by pCLE. Moreover, the evaluation of tumor vasculature by real-time assessment may provide useful information to achieve tailored therapeutic interventions for gastric cancer patients