Review article: somatostatin analogues in the treatment of gastroenteropancreatic neuroendocrine (carcinoid) tumours

Abstract

The discovery of somatostatin (SST) and the synthesis of a variety of analogues constituted a major therapeutic advance in the treatment of gastroenteropancreatic neuroendocrine (carcinoid) tumours (GEP-NETs). They currently provide the most efficient treatment to achieve symptomatic relief and have recently been demonstrated to inhibit tumour growth. To review 35 years of experience regarding the clinical application and efficacy of SST analogues. The PubMed database (1972-2009) was searched using somatostatin as a search term with combinations of terms including 'treatment'; 'neuroendocrine'; 'carcinoid'; 'tumor'; 'octreotide'; 'lanreotide' and 'pasireotide'. In a review of 15 studies including 481 patients, the slow-release formulations Sandostatin LAR and Somatuline SR/Autogel achieved symptomatic relief in 74.2% (61.9-92.8%) and 67.5% (40.0-100%), biochemical response in 51.4% (31.5-100%) and 39.0% (17.9-58%), and tumour response in 69.8% (47.0-87.5%) and 64.4% (48.0-87.0%) respectively. Novel SST analogues like SOM230 (pasireotide) that exhibit pan SST receptor activity and analogues with high affinity to specific somatostatin receptor (sstr) subtypes may further advance the field, but efficacy studies are lacking. As more precise understanding of NET cell biology evolves and molecular biological tools advance, more accurate identification of individual tumours sstr profile will probably facilitate a more precise delineation of SST analogue treatment.