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Background and aims. The role of angiogenesis in progression and metastasis of gastric cancer has been studied over the last years. The aim of our study was to assess the microvessel density and vascular endothelial growth factor (VEGF) expression in correlation with prognosis, survival and the risk for upper gastrointestinal (GI) bleeding as well. Method. We prospectively assessed angiogenesis in 40 patients with gastric carcinoma. Microvessel density was calculated using CD31 and CD34 markers, and VEGF expression was assessed in biopsy samples. The tumor stage was established using imaging methods: CT scan for M and N stage and endoscopic ultrasound for T and N stages. The correlation between pathological markers and tumor stage, survival rate and risk of upper gastrointestinal bleeding was assessed. Results. The study included 40 patients with gastric cancer; among them 8 patients presented with upper GI bleeding. The average microvessel density was 10.21 for CD31 and 11.85 for CD34 in all patients VEGF was positive only in 45% of patients. The microvessel density was higher in patients with advanced TNM stage, and a correlation with the risk of UGIB and survival rate was also found. VEGF expression correlated with TNM stage and with the risk of upper GI bleeding. Conclusions. Microvessel density (estimated by CD34) was involved in locally advanced disease, while VEGF was correlated with loco-regional extension and distant metastasis in gastric cancer patients. There was a clear correlation between angiogenic parameters, survival rate and the risk of upper GI bleeding. [ABSTRACT FROM AUTHOR]

The tumor microcirculation is characterized by an abnormal vascular network with dilated, tortuous and saccular vessels. Therefore, imaging the tumor vasculature and determining its morphometric characteristics represent a critical goal for optimizing the cancer treatment that targets the blood vessels (i.e. antiangiogenesis therapy). The aim of this study was to evaluate new vascular morphometric parameters in colorectal cancer, difficult to achieve through conventional immunohistochemistry, by using the confocal laser endomicroscopy method. Fresh biopsies from tumor and normal tissue were collected during colonoscopy from five patients with T3 colorectal carcinoma without metastasis and were marked with fluorescently labeled anti-CD31 antibodies. A series of optical slices spanning 250 µm inside the tissue were immediately collected for each sample using a confocal laser endomicroscope. All measurements were expressed as the mean ± standard error. The mean diameter of tumor vessels was significantly larger than the normal vessels (9.46±0.4 µm vs. 7.60±0.3 µm, p = 0.0166). The vessel density was also significantly higher in the cancer vs. normal tissue samples (5541.05±262.81 vs. 3755.79±194.96 vessels/mm3, p = 0.0006). These results were confirmed by immunohistochemistry. In addition, the tortuosity index and vessel lengths were not significantly different (1.05±0.016 and 28.30±3.27 µm in normal tissue, vs. 1.07±0.008 and 26.49±3.18 µm in tumor tissue respectively, p = 0.5357 and p = 0.7033). The daughter/mother ratio (ratio of the sum of the squares of daughter vessel radii over the square of the mother vessel radius) was 1.15±0.09 in normal tissue, and 1.21±0.08 in tumor tissue (p = 0.6531). The confocal laser endomicroscopy is feasible for measuring more vascular parameters from fresh tumor biopsies than conventional immunohistochemistry alone. Provided new contrast agents will be clinically available, future in vivo use of CLE could lead to identification of novel biomarkers based on the morphometric characteristics of tumor vasculature. [ABSTRACT FROM AUTHOR]

Confocal laser endomicroscopy (CLE) has been recently proposed as a new technique that allows in vivo histologic assessment of mucosa during endoscopy. The most commonly used contrast agents are acriflavine hydrochloride and fluorescein sodium. For colon pathology assessment, the administration of fluorescein intravenously produces a strong staining of both surface epithelium and deeper layers of lamina propria. Confocal laser endomicroscopy is a feasible method to diagnose colon cancer in vivo. Furthermore, confirmation of neoplastic changes using CLE during colonoscopy may lead to major improvements in the clinical management of the patients with inflammatory bowel disease. Biopsies can be limited to targeted sampling of relevant lesions. Confocal laser endomicroscopy will certainly play an important diagnostic role during gastrointestinal endoscopy in the future, enabling the elimination of the diagnostic delay associated with conventional biopsy preparation and processing. [ABSTRACT FROM AUTHOR]