In vitro and in vivo expression of somatostatin receptors in intermediate and malignant soft tissue tumors

Background: Previous studies showed that the subtype 2 of somatostatin receptors (sstr₂) is generally expressed by soft tissue sarcomas. Materials and Methods: Using reverse transcription-polymerase chain reaction (RT-PCR), the present study evaluated the expression of sstr mRNA in 31 human intermediate and malignant soft tissue tumors. In 8 patients somatostatin receptor scintigraphy was performed to detect soft tissue tumor sites and visualize in vivo sstr expression. Results: Somatostatin receptors were identified in 84% of the tumors analyzed by RT-PCR analysis. sstr₁ and sstr₂ were the receptors most frequently detected. Somatostatin receptor scintigraphy was able to identify primary and/or metastatic sites in 7 out of 8 patients, with an overall sensitivity per site of 87%. Concordant results were found between in vitro and in vivo techniques. Conclusion: The wide expression of sstrs in soft tissue tumors suggest a relevant role for these receptors in diagnosis and may have therapeutic applications.