Variable somatostatin receptor subtype expression in 151 primary pheochromocytomas and paragangliomas.

Variable somatostatin receptor subtype expression in 151 primary pheochromocytomas and paragangliomas.

Hum Pathol. 2018 Dec 07;:

Authors: Leijon H, PhL SR, Hagström J, Louhimo J, Mäenpää H, Schalin-Jäntti C, Miettinen M, Haglund C, Arola J

Abstract
Pheochromocytomas (PHEOs) and paragangliomas (PGLs) are neuroendocrine tumors (NETs) that express somatostatin receptors (SSTRs), a phenomenon that constitutes a basis for tumor imaging and treatment with somatostatin analogues and Peptide Receptor Radionuclide Therapy (PRRT). We studied the immunohistochemical expression of SSTR1-5 in 151 primary tumors, including 14 metastasized and 16 SDHB-deficient tumors. SSTR2 and SSTR3 were most abundantly present in these tumors, whereas the tumors were mostly negative for SSTR1, SSTR4 and SSTR5. All metastasized PGLs (9/9), but only one metastasized PHEO (1/5), were strongly SSTR2-positive. SSTR3 expression was lower in metastatic tumors and tumors with a high proliferation rate (MIB1≥5%), but tumors had variable individual SSTR-profiles. No correlation was found between SDHB status and SSTR expression. Our results suggest that new SSTR analogues with affinity for several SSTRs could be relevant for a subgroup of patients with these tumors. Better knowledge of tumors SSTR profiles could open the door for personalized imaging and treatment in the future. Because SSTR profiles vary in PHEOs and PGLs, individual analysis is required for each tumor.

PMID: 30529752 [PubMed - as supplied by publisher]

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