Somatostatin receptors in nasopharyngeal carcinoma

Abstract.

Somatostatin receptors (SS-Rs) are expressed in neuroendocrine tumour tissues where they can be targetted for diagnosis and therapy. This study investigated the presence of SS-Rs in nasopharyngeal carcinoma (NPC), a common cancer in South-East Asia. Nasopharynx biopsy specimens were obtained from 12 NPC patients and 5 patients without tumours. Somatostatin receptor autoradiography was performed using ¹²⁵I-labelled [Tyr³]-octreotide and ¹²⁵I-labelled [Leu⁸, DTrp²², Tyr²⁵]-somatostatin-28 as radioligands. Of the 12 NPC samples 9 showed moderate to high expression of SS-Rs. These were of the sst₂ type, based on the rank order of potency of subtype-selective analogues. The 5 non-neoplastic samples, consisting primarily of granulomatous tissue, did not express measurable amounts of SS-Rs. This study demonstrates for the first time the presence of type 2 SS-R in NPC. These receptors may play a role in the management of NPC, as is the case for other somatostatin-expressing tumours.