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neuroendocrine article

The use of Lanreotide in the Treatment of Metastatic Neuroendocrine Tumors

By Morolake Amole

Neuroendocrine tumors or NET’s are a group of very rare and very interesting tumors that arise from various endocrine and neuronal tissues. Annually, in the United States, there are approximately 5 new cases per every 100,000 persons. This statistic makes it quite obvious that this group of disorders is relatively rare and thus it is understandable why there are few available and effective treatments.

Neuroendocrine tumors are a varied group of tumors that often arise from the gastrointestinal tract and the pancreas. Comprising this group of little known disorders are carcinoid tumors, found predominately in the gut or the appendix and also islet cell tumors, which are cancerous proliferations in the islet cells of the pancreas. The Islet cells are responsible for the secretion of insulin, so individuals with islet cell tumors tend to over secrete insulin and thus suffer a variety of symptoms that are related to hypoglycemia or low blood glucose.

NET’s are classified based on a variety of characteristics but for the purposes of treatment, there are two very important classifications; whether the tumors are functional and whether they are metastatic. A functioning tumor is secretory, meaning that it is secreting some sort of substance. For instance, Islet cell tumors, as described above, secrete the metabolic hormone insulin. Carcinoid tumors secrete the vasoactive neurotransmitter serotonin. Serotonin and its breakdown products are the cause of symptoms such as flushing, diarrhea and wheezing in individuals with carcinoid tumors. The other important classification of neuroendocrine tumors is whether or not they are metastatic, meaning that they are no longer contained and have begun to invade another tissue.

Based on whether the tumor is functional or metastatic, one of 3 treatments is recommended; surgery to remove the tumor, anti-secretory medications to reduce the effects of secreted neurotransmitters and hormones with chemotherapy to treat metastatic disease. Since most NETs are inoperable and secretory, medical therapy is the mainstay of treatment and is often accomplished through the use of somatostatin analogues like Octreotide and Lanreotide. An analogue is a substance that mimics the effects of another natural substance. In this case, Octreotide and Lanreotide mimic the effects of the inhibitory hormone somatostatin, which is normally secreted in several areas of the gastrointestinal tract like the intestines and pancreas.

A recent paper published in the New England Journal of Medicine, showed how extended-release Lanreotide used in 120mg doses was able to confer “progression-free” survival in patients suffering from metastatic pancreatic neuroendocrine tumors. This is a very interesting finding considering that somatostatin analogues like Octreotide are often used for non-metastatic neuroendocrine tumors mainly as symptomatic treatment and not for their anti-proliferative effects. So what is the difference between Octreotide and Lanreotide that makes Lanreotide a more potent anti-proliferative agent? Lanreotide is a longer acting agent than Octreotide and therefore there pharmacokinetics and administration may be different. However, there is no completely acceptable answer to this question. What has been proven is that the use of an already available drug can be extremely beneficial in the treatment of neuroendocrine tumors.

What this means to you?
If you are a patient with a neuroendocrine tumor; whether secretory or non-secretory, metastatic or non-metastatic, Lanreotide, a longer acting somatostatin analogue is an excellent treatment because it has been shown to provide increased progression-free survival in patients suffering from pancreatic neuroendocrine tumors.

Citations:
M Caplin, M Pavel, J Cwikla. Lanreotide in Metastatic Enteropancreatic Neuroendocrine Tumors. The New England Journal of Medicine. 2014 July 17, 2014; 371;3 224-233.