O129 CLASSIFICATION OF BARRETT’S CARCINOMA SPECIMENS BY HYPERSPECTRAL IMAGING (HSI)

Aim Hyperspectral imaging (HSI) technology combines imaging with spectroscopy and can be used for the classification of malignant and non-malignant cells. Thereby HSI combined with artificial intelligent algorithms can be used to predict tumor cells in in Barrett’s carcinoma specimens. Methods HSI imaging records light between the visual and near-infrared light (500-1000nm). For a first feasibility study, this technique was used to discriminate between squamous epithelium and esophageal adenocarcinoma and 45 specimens from Barrett’s carcinoma patients were recorded. In 22 of the 45 investigated specimens contained also squamous epithelium. The specimens were fixed routinely after resection in paraformaldehyde, were sliced to 3μm, and were stained by haematoxylin and eosin (HE). A non-parametric supervised classification learning algorithm (K-nearest neighbours (k-NN)) was used for discrimination. Results Barrett’s adenocarcinoma cells were recorded by HSI in all 45 investigated cases. Squamous epithelium and Barrett’s adenocarcinoma cells displayed differences in the absorbance between the wave lengths of 500 to 700 nm. For both, the squamous epithelium and the Barrett’s adenocarcinoma cells, the intra group variances of the investigated specimens were quite low. 333,275 and 74,000 spectra could be measured from Barrett’s adenocarcinoma and from squamous epithelium, respectively. Specificity, sensitivity and precision with a k-NN (k=5) classifier were 0.74, 0.92 and 0.94 for the presence of Barrett’s adenocarcinoma cells. Conclusions HE-stained squamous epithelium and Barrett’s adenocarcinoma cells showed specific spectral alterations, when measured by HSI. These characteristics could be used in the future to develop a computer-assisted algorithm to discriminate semi-automated for tumor cells Barrett’s carcinoma specimens, which will help to foster decision-making support in histopathological diagnosis.

Association of the simultaneous expression of ephrin B3 receptor and E-cadherin in Barrett's adenocarcinoma with favorable clinical staging.

e14527 Background: In intestinal epithelium tyrosine kinase receptor Ephrin B3 maintains the architecture of the crypt-villus axis by repulsive interaction with its ligand ephrin-B1. While loss of Ephrin B3 is linked to colorectal cancer initiation, overexpression of Ephrin B3 in cancer cell lines inhibits growth and induces functional changes with decreased mesenchymal and increased epithelial markers. In order to study this tumor suppressor activity of Ephrin B3 in esophageal adenocarcinoma we analysed the simultaneous expression of Ephrin B3 and E-cadherin in healthy esophagus and Barrett’s carcinoma. Methods: Simultaneous expression was investigated in samples of 141 patients with Barrett’s carcinoma and of 20 healthy esophagi. For analysis immunhistology and quantitative PCR was used. Results of healthy squamous epithelium, Barrett’s metaplasia and staging specific esophageal adenocarcinoma were correlated. Results: A significantly reduced E-cadherin mRNA activity in adenocarcinoma compared to dysplasia could be detected. Immunhistological activity of E-cadherin and Ephrin B3 was reduced in adenocarcinoma compared to dysplasia or healthy esophageal mucosa. The intracellular E-cadherin distribution changed significantly from the cytoplasm to the membrane, when Ephrin receptor was simultaneously expressed. Simultaneous expression of E-cadherin and Ephrin B3 showed a significant inverse correlation to tumorstage. Conclusions: We present first evidence of the tumor suppressor activity of Ephrin B3 receptor in esophageal adenocarcinoma possibly due to the impact on redistribution of cellular E-cadherin to the membrane. Our results suggest that this effect might play a role in the dysplasia-adenocarcinoma-sequence, the infiltrative growth pattern and the development of lymph node metastases.