The role of octreotide in the treatment of gastroenteropancreatic endocrine tumors

Gastrointestinal-endocrine pancreatic (GEP) tumors are rare, occurring in less than 1% of the population. They are usually divided into functionally active or nonfunctioning tumors. Functionally active tumors produce a variety of substances (mainly peptides or serotonin). The tumors are classified according to the dominant clinical syndrome that they cause, Surgery is the treatment of choice in patients with GEP tumors and it should always be considered, even if total tumor excision cannot be achieved. Reduction in tumor mass (debulking) may improve the patients symptoms. Medical treatment is used in patients with advanced malignant endocrine tumors. The most important compounds to control symptoms in these patients are somatostatin analogues, Natural somatostatin is produced in different molecular forms and has inhibitory effects on a number of functions. The observation of potent inhibitory effects on various hormone-secreting cells led to the use of somatostatin for symptomatic treatment of peptide-secreting tumors. Natural somatostatin is not suitable for long-term clinical application; therefore, synthetic somatostatin analogues were developed with improved pharmacokinetic characteristics. The best characterized analogue, octreotide, has been successfully applied to patients with functioning GEP tumors. Octreotide can dramatically ameliorate the debilitating symptoms of patients suffering from the clinical manifestations of endocrine tumors such as diarrhea and flushing. The success of octreotide therapy is best reflected in terms of its impact on the patient's quality of life as defined by the activity to perform normal daily activities.