Is There an Additional Value of Somatostatin Receptor Subtype 2A Immunohistochemistry Over Somatostatin Receptor Scintigraphy in Predicting Gastroenteropancreatic Neuroendocrine Tumor Response?

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Introduction: It is not known whether tumoral somatostatin receptor subtype 2a (sst2a) immunohistochemistry (IHC) has additional value over OctreoScan® uptake in predicting response to PRRT in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

Aim(s): The aims were to: 1) establish sst2a positivity in GEP-NET samples of patients who had been treated with PRRT using 177Lu-octreotate, 2) determine the relationship between GEP-NET response to PRRT and tumoral sst2a expression, and 3) compare patients characteristics with sst2a negative and positive tumors.

Materials and methods: We have selected 75 consecutive GEP-NET patients who had undergone PRRT using 177Lu-octreotate and who had follow-up by computed tomography (CT). Tumoral sst2a expression was determined by IHC. Tumor response to CT scans was scored according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria.

Conference: 12th Annual ENETSConcerence (2015)

Presenting Author: van Adrichem R

Authors: Van Adrichem R, Kamp K, Van Deurzen C, Biermann K, Feelders R,

Keywords: sst2a,