Up until 4 years ago, I didn’t have a clue about hormones – it’s one of those things you just take for granted. However, hormones are vital to human health (male and female) and it’s only when things go wrong you suddenly appreciate how important they are ……..like a lot of other things in life I suppose! My interest started when I was diagnosed with metastatic Neuroendocrine Tumours (NETs) in 2010.
This is a really complex area and to understand the hormone problems associated with Neuroendocrine Cancer, you need to have a basic knowledge of the endocrine and neuroendocrine systems. I’ve no intention of explaining that (!) – other than the following high level summary:
So are hormones ‘horrible’ as my title indicates? Absolutely not, they are essential to the normal function of the human body. For example if you didn’t have any of the hormone Serotonin in your system, you would become extremely ill. On the other hand, if your glands start secreting too much of certain hormones, your body could become dysfunctional and in some scenarios, this situation could become life threatening. So hormones are good as long as the balance is correct.
I used the example of Serotonin above because it is directly connected to some of the issues faced by NET Cancer patients, in particular the most common variant known as Carcinoid. Serotonin is a monoamine neurotransmitter synthesized from Tryptophan, one of the eight essential amino acids (defined as those that cannot be made in the body and therefore must be obtained from food or supplements). About 90% of serotonin produced in the body is found in the enterochromaffin cells of the gastrointestinal (GI) tract where it is used to regulate intestinal movements. The remainder is synthesized in the central nervous system where it regulates mood, appetite, and sleep.
Sometimes the cause of the excessive hormone secretion is due to malignant cancer cells and my type of cancer falls into this category. Some NETs (more commonly NETs of the small intestine or appendix) may overproduce serotonin (and other substances) which can cause a characteristic collection of symptoms called carcinoid syndrome. The key symptoms are flushing, diarrhea and general abdominal pain, loss of appetite, fast heart rate and shortness of breath and wheezing. The main symptom for me was facial flushing and this was instrumental in my eventual diagnosis. The fact that I was syndromic at the point of diagnosis made it easier to discover – albeit the trigger for the investigation was a fairly innocuous event!
Excessive secretions or high levels of hormones and other substances can be measured in a number of ways but the main ones for NET Cancer (Carcinoid) are Chromogranin A (CgA) blood test and 5-Hydroxyindoleacetic Acid (5-HIAA) 24 hour urine test. By measuring the level of 5-HIAA in the urine, healthcare providers can calculate the amount of serotonin in the body. The 5-HIAA test is the most common biochemical test for carcinoid syndrome. If you’ve understood the text above, you can now see why there are dietary and drug restrictions in place prior to the test. CgA is a blood test which measures a protein found in carcinoid tumour cells. This test is normally associated with tumour mass rather than tumour activity/functionality.
One of the key treatment breakthroughs for NET cancer patients, particularly those who have shown symptoms of carcinoid syndrome, is ‘Somatostatin Analogues’, branded as Octreotide or Lanreotide (mainly). Patients will normally be prescribed these drugs once it has been ascertained their tumours have the necessary avidity to them. This is another complex area but I’ll try to describe the importance here in basic terms. Somatostatin is a naturally occurring protein in the human body. It is an inhibitor of various hormones secreted from the endocrine system and it binds with high affinity to the five somatostatin receptors found on secretory endocrine cells. Carcinoid tumors have membranes covered with receptors for somatostatin. However, the naturally occurring Somatostatin has limited clinical use due to its short half-life (<3 min). Therefore, specific somatostatin analogues (synthetic versions) have been developed that bind to tumours and block hormone release. Thus why Octreotide and Lanreotide do a good job of slowing down hormone production, including many of the gut hormones controlling emptying of the stomach and bowel. It also slows down the release of hormones made by the pancreas, including insulin. It’s also why Octreotide is used in radioactive scans as the mix of radioactivity and octreotide binds to the tumours making them ‘light up’ and show on the gamma camera pictures.
Other types of NETs are also affected by the overproduction of hormones including Insulinomas, Gastrinomas, Glucagonomas,VIPomas and Somatostatinomas. if you want to read more detail I suggest the “5th edition handbook, Neuroendocrine Tumors: A Comprehensive Guide to Diagnosis and Management” which is available for download or a hard copy by post – contact ISI at requests@interscienceinstitute.com (they will post to UK – it worked for me!). Table 1.1 on page 5 is a good starting point.
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Read about my diagnosis here: http://wp.me/p4AplF-1W
Read about my 4 year ‘canniversary‘ here: http://wp.me/p4AplF-c
Finally please note this text is my interpretation and my own understanding – it should not be a substitute for professional medical advice.
thanks
Ronny
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