Theranostics2016 4th Theranostics World Congress 2016 Spotlight on Neuroendocrine tumours (17 abstracts)
1Department of General and Visceral Surgery, Zentralklinik Bad Berka, Bad Berka, Germany; 2Laboratory of Pathology and Cytology Bad Berka, Bad Berka, Germany; 3Institute of Pathology, Charité University Hospital Berlin, Berlin, Germany; 4Department of General, Visceral Transplantation, Vascular and Thoracic Surgery, Hospital of the University of Munich, Munich, Germany; 5Department of Pathology, Ludwig-Maximilians-University Munich, Munich, Germany; 6Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Bad Berka, Germany; 7Institute of Pharmacology and Toxicology, Jena University Hospital, Jena, Germany.
Background: Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis is observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed.
Aims: In the present study the expression of the five somatostatin receptor (SSTR) subtypes as well as of the chemokine receptor CXCR4 and of the endothelin receptor A (ETA) was evaluated.
Methods: Receptor expression was assessed by means of immunohistochemistry using a panel of novel rabbit monoclonal antibodies in a total of 54 paraffin-embedded paraganglioma tumor samples from 43 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data.
Results: The SSTR2 was by far the most prominent receptor in the paragangliomas investigated. It was present in all samples at a high intensity, followed by the SSTR5, the SSTR1, the SSTR3 and the SSTR4. The CXCR4 and the ETA were seen only in a few cases on the tumor cells. However, with respect to the tumor blood vessels, in all cases an exceptionally strong staining for the ETA and in the majority of the samples also for the CXCR4 was noticed.
Conclusions: Due to the high expression rate found in the present study, paragangliomas seem to be well suited for SSTR2-based diagnostics and therapies. Additionally, an indirect targeting of these highly vascularized tumors via the CXCR4 or the ETA may represent a promising future strategy.