Quantitative Assessment of 99mTc-Depreotide Uptake in Oesophageal Cancer and Precursor Conditions and Its Reflection in Immunohistochemically Detected Somatostatin Receptors

Background. Somatostatin receptors (SSTRs) are over-expressed in several tumors making it possible for imaging with labelled SSTR. A previous study showed feasibility to image oesophageal cancer with SSTR analogue 99mTc-depreotide. Purpose. (1) To investigate expression of the SSTRs in different types of esophageal carcinoma and (2) to correlate such an expression with 99mTc-depreotide uptake in these lesions. Material and Methods. Total 28 patients (17 with esophageal cancer and 11 with Barrett's esophagus) were examined with 99mTc-depreotide scintigraphy. The SSTR2A, SSTR2B, SSTR3, and SSTR5 were analyzed immunohistochemically in the lesion samples. Results. Among the patients with adenocarcinoma 10/11 expressed different amounts of SSTRs, while SSTRs were absent in 5/6 patients with Squamous cell carcinoma (Sqcc). There was no correlation neither between the 99mTc-depreotide uptake and the amount of SSTRs nor between the amount of SSTRs and differentiation grade of the tumor. Conclusions. (1) SSTRs are expressed in esophageal carcinoma and more abundantly so in adenocancer specimens; (2) in vivo 99mTc-depreotide uptake does not obviously correlate with the immunohistochemically detection of SSTRs of different subtypes in esophageal carcinoma