Neuroendocrine Cancer Syndromes – Early Signs of a Late Diagnosis

Early signs of a late diagnosis (2)One of the curious things about Neuroendocrine Cancer (NETs going forward) is that it can very often exhibit one or more vague symptoms collectively known as a ‘syndrome’.  Syndrome is an apt word to describe these complications as the most general meaning in medical terms is a group of symptoms that together are characteristic of a specific disorder or disease”.  Having a syndrome can often be the difference between having a ‘functional’ condition or a non-functional’ condition – see more below.

This frequently makes Neuroendocrine Cancer very difficult to diagnose quickly.  It’s a very devious disease.

It’s not all about Carcinoid Syndrome!

Most people think of Carcinoid Syndrome when they discuss NETs. Anyone suggesting that all NET patients get carcinoid syndrome or that all symptoms of NETs are caused by carcinoid syndrome, is WAY off the mark. Firstly, not everyone will have a ‘syndrome’ in addition to their tumours – the percentage is actually well below 50%. Secondly, there are in actual fact, several associated syndromes depending on the anatomical location and type of NET. As an example of one syndrome, statistics vary from source to source but it is estimated that around a 30-45% of all ‘midgut’ patients will present with metastatic disease and around a third of those (∼10-15% of all midgut) will exhibit Carcinoid Syndrome indicating their tumours are ‘functional’ (secreting excess hormones, particularly serotonin).  It follows that Carcinoid Syndrome itself is not that common and it could be the same with other types of NET (even though it can appear more prevalent on forums).

Diagnostic Challenges in NETs (this graphic only covers so-called Carcinoid Syndrome).  Inner segments are the key symptoms, outer segments are some of the potential misdiagnosis/delayed diagnosis. Graphic courtesy of Modlin IM, Kidd M, Latich I, et al. Current status of gastrointestinal carcinoids. Gastroenterology 2005; 128: 1717-1751

Functional / Non-Functional

These tumours and associated syndromes are treatable for most but the difficult part can be arriving at a diagnosis. Moreover, without a syndrome, some of these tumours can be silently growing and as they grow slowly, the ‘silence’ can go on for some years. Even with a syndrome, the root cause can remain disguised as the symptoms are similar to many day-to-day illnesses, again the reason for the title of this blog. Curiously, the lack of a syndrome can sometimes lead to an even later presentation and the consequences that arise (i.e. no signs to aid a diagnosis). In fact a large proportion of Pancreatic NETs are non-functional at diagnosis. There can be the odd exception but in general terms, NETs are either functional (with a syndrome) or non-functional (no syndrome). It’s also possible that patients can move from one state to another.

It’s useful to know about the range of tumor markers and hormone markers – read more here

Syndrome and Tumors – ‘Chicken or Egg’ ?

I’m always confused when someone says they have been diagnosed with a Syndrome rather than a NET type.  You normally need a tumor to produce the symptoms of a syndrome.

The exception might be hereditary syndromes e.g. MEN.  MEN syndromes are genetic conditions. This means that the cancer risk and other features of MEN can be passed from generation to generation in a family. A mutation (alteration) in the various MEN genes gives a person an increased risk of developing endocrine/neuroendocrine tumors and other symptoms of MEN. It’s also possible that the tumors will be discovered first.  It’s complex!

Major NET Syndromes  

(information mainly taken from the ISI Book on NETs with a cross-reference from ENETS and UKINETS Guidelines)

The ISI Book on Neuroendocrine Tumors 2016 (Woltering et al) confirms there are a number of syndromes associated directly and indirectly with NETs and are described as individual syndromes according to their secretory hormones and peptides. The reference publication expands on this list to aid diagnoses by including common presentations, associated tumour types and locations and the offending secreting hormones. You can see why Neuroendocrine Cancer is a diagnostic challenge!

Carcinoid – a syndrome connected with (mainly) serotonin secreting tumours in certain locations (mainly small intestine, lung, stomach, appendix, rectum). The key symptoms include diarrhoea, flushing of the skin (particularly the face), stomach cramping, heart problems such as palpitations, and wheezing. The syndrome is actually caused by the release of a number of hormones, in particular Serotonin, Bradykinin, Tachykinin (Substance P), Histamine, and Prostaglandins.

(there’s also a very rare instance of pancreatic based tumours producing carcinoid syndrome effects – according to ENETs less than 1% of all tumours associated with carcinoid syndrome)

Whipple’s Triad – Whipple’s Triad is the classic description of insulinoma which includes symptoms of hypoglycemia with a low blood glucose concentration relieved by the ingestion of glucose. These tumours can be located anywhere within the pancreas in the cells that make insulin. Insulin is a hormone that controls the amount of  glucose (sugar) in the blood. It moves glucose into the cells, where it can be used by the body for energy. Insulinomas are usually slow-growing tumors that rarely spread. Some of these tumours will be associated with MEN1 syndrome.

Zollinger-Ellinson SyndromeA tumour that forms in cells that make gastrin and can be known as a Gastrinoma. Gastrin is a hormone that causes the stomach to release an acid that helps digest food. Both gastrin and stomach acid are increased by gastrinomas.  This is a condition in which one or more tumours form in the pancreas, the upper part of the duodenum or the stomach (these organs are very close and tightly packed together). These tumours secrete large amounts of the hormone gastrin, which causes your stomach to produce too much acid. The excess acid can lead to peptic ulcers, in addition to diarrhea and other symptoms.  Associated with Gastrinoma (pNET) and Gastric NETs.  Some of these tumours may be associated with MEN1 syndrome.

Werner-Morrison SyndromeVasoactive Intestinal Peptide (VIP) is secreted thus the pNET term – VIPoma –  Sometimes the syndrome is referred as WDHA – Watery Diarrhea, Hypokalemia (potassium deficiency), and Achlorhydria (absence of hydrochloric acid in gastric secretions).  Sometimes known as Pancreatic Cholera. Some of these tumours may be associated with MEN1 syndrome

Glucagonoma.  A tumour that forms in cells that make make glucagon. Glucagon is a hormone that increases the amount of glucose in the blood. It causes the liver to break down glycogen. Too much glucagon causes hyperglycemia (high blood sugar) rendering most patients diabetic. A glucagonoma usually forms in the tail of the pancreas.  Some of these tumours may be associated with MEN1 syndrome.  See also Sweet’s Syndrome below.  Sometimes known as the 4D syndrome – Dermatological, Diabetes, DVT, Depression.

Somatostatinoma is a very rare type of NET, with an incidence of one in 40 million persons. These tumours produce excess somatostatin arise from the delta cells in the pancreas, although these cells can also be present in duodenal/jejunum tissue where around 44% of these tumours occur. Somatostatin is a naturally occurring peptide that inhibits the function of almost all gut hormones (author’s note – this fact should give you an appreciation of how somatostatin analogues tackle associated syndromes whilst giving you certain side effects as a result!)

Pancreatic Polypeptide (PP)PPoma A complicated one and not too much information (even in the ISI book or ENETS Guidelines). However, it’s the third most common type of islet cell tumour (i.e. pNET).  The function of pancreatic polypeptide is not completely understood. Patients present with weight loss, jaundice, and abdominal pain. The diagnosis is confirmed by pancreatic polypeptide levels > 300 pg/ml. Some of these tumours may be associated with MEN1 syndrome.

Hedinger Syndrome – the technical name for Carcinoid Heart Disease and an ideal replacement term now that Carcinoid is being phased out.

Cushing’s – also known as hypercortisolism.  A collection of symptoms caused by very high levels of a hormone called cortisol in the body.   In Cushing’s disease, oversecretion of pituitary ACTH induces bilateral adrenal hyperplasia. This results in excess production of cortisol, adrenal androgens, and 11-deoxycorticosterone. Cushing’s disease, a subset of Cushing’s syndrome, is due to a pituitary corticotroph adenoma and results in a partial resistance to the suppression of ACTH by cortisol so that secretion is unrestrained. In contrast, causes of Cushing’s syndrome may include the following:

•   Adrenal adenoma or carcinoma arise spontaneously. ACTH levels are undetectable.

•   Non-pituitary (ectopic) tumours produce ACTH. They most frequently originate in the thorax and are highly aggressive small cell carcinomas of the lung or slow- growing bronchial or thymic carcinoid tumours. Some produce corticotropin- releasing hormone (CRH) instead, which stimulates pituitary ACTH secretion and can therefore mimic a pituitary tumour.

•   Other causes include NETs of the gastric, pancreatic, and intestinal organs; Pheochromocytomas, and MCT.

The hallmark of Cushing’s syndrome is that ACTH levels are partially resistant to suppression with dexamethasone, even at very high doses. Some MEN patients with pituitary tumours may have Cushing’s Syndrome. AdrenoCorticoTropic Hormone (ACTH) releasing tumours are somerimes known as ACTHoma.

Sweet’s – Dermatitis/rash associated with Glucagonomas.  Not to be confused with Pellagra (B3 deficiency)

Neuroendocrine / Endocrine tumors can be seen in several inherited familial syndromes, including but not limited to:

  • Multiple Endocrine Neoplasia type 1 (MEN1)
  • Multiple Endocrine Neoplasia type 2 (MEN2)
  • Multiple Endocrine Neoplasia type 4 (MEN4)
  • SDHx mutations – Hereditary Pheochromocytoma/Paraganglioma Syndromes.
  • Pituitary.
  • Von Hippel-Lindau (VHL) Disease
  • Neurofibromatosis Type 1 (also known as Recklinghausen’s Disease). Not covered further.
  • Tuberous Sclerosis (not covered further)
  • Carney Complex

see Genetics and Neuroendocrine Tumors

MEN1 – Mainly involved the 3 Ps, Pituitary, Pancreas and Parathyroid.  The pituitary tumours are primarily Prolactinomas, the pancreatic tumours are mainly PPomas, Gastrinomas and Insulinoma.  Many also have association with Zollinger-Ellinson  syndrome (ZES).  Sometimes known as Wermer Syndrome.  Associated with the MEN1 gene.

MEN2A – associated with the RET gene, can result in Medullary Thyroid Carcinoma, Pheochromocytoma, and overactive parathyroid glands characterised by a high calcium level.

MEN2B. An inherited disorder characterised by the certain development of Medullary Thyroid Carcinoma, plus the possible development of pheochromocytomas and characteristic tumours (mucosal neuromas) of the lips, tongue and bowels. Parathyroid disease is extremely rare in MEN2B.  Also connected with the RET gene.

MEN4.  A relatively new MEN variant and related to the CDKN1B gene.  Similar to MEN1 but normally only 2 of the 3 Ps, parathyroid and pituitary; and potentially other places.

SDHx mutations/Hereditary pheochromocytoma/paraganglioma syndromes

  • Succinate dehydrogenase (SDH) is an enzyme which is important for the metabolic function of mitochondria. Patients with mutations of these genes have increased risk of pheochromocytomas, paragangliomas, stomach tumors and kidney tumors.
  • SDHx mutations (SDHA, SDHB, SDHC, and SDHD) can present as Pheochromocytomas/Paragangliomas and other non-NET conditions.  If this interests you see site http://www.SDHcancer.org

Von Hippel-Lindau (VHL) – not an exclusively NET syndrome. VHL is a rare disorder caused by a faulty gene. It is named after the two doctors who first described the disease, and affects about one in 35,000 people. Tumours develop in one or more parts of the body. Many of these tumours involve the abnormal growth of blood vessels in parts of the body which are particularly rich in blood vessels. Areas most frequently affected are the eyes, the back of the brain (cerebellum), the spinal cord, the kidneys, the adrenal glands and the pancreas. People are affected differently, even within the same family. The only VHL tumour which tends to run in families affects the adrenal glands (Pheochromocytoma). Different VHL features tend to develop at different ages. The eye angiomas often develop in childhood. Others, including tumours found in the cerebellum, spinal cord or adrenal glands (Haemangioblastomas and Pheochromocytomas) can develop from late childhood onwards. The kidney tumours are usually the last things that develop, from the mid-twenties onwards.  Most VHL related tumours are benign.

Summary

As for my own experience of syndromes, I did once show symptoms of the most common NET syndrome (currently known as Carcinoid syndrome) where the key symptoms include diarrhoea, flushing of the skin (particularly the face), stomach cramping, heart problems such as palpitations, and wheezing.  You can see why those symptoms are frequently and easily confused with other conditions. If you have a similar diagnosis, you may benefit from looking at something known as The 5 E’s which is a useful list of things to be wary of.

I did have issues for a year or two in 2010 leading up to diagnosis and until my treatment was underway.  I was experiencing flushing and infrequent bouts of diarrhea but I totally ignored it (hear me talk about this). However, it ended up being instrumental in my diagnosis albeit some good luck was involved in getting to that point.  My twist of fate which involved a low hemoglobin score led me to a scan and ‘bingo’.  I had a ‘gastrointestinal blip’ some 18 months previously but that proved colonoscopy negative.  Despite my distant and metastatic tumour disposition and seemingly late diagnosis, I’m current non-syndromic due to “early” intervention and good treatment.  However, my ongoing treatment continues to play its part.

For many, the vague and routine symptoms generated by a syndrome contribute to the fact that NET Cancer is frequently misdiagnosed with some people suffering from the side effects for many years before a correct diagnosis is made.

There are many other less known syndromes that appear to be directly or indirectly connected with Neuroendocrine Tumours and I may update this post if I discover they are more prevalent than I think.  Please let me know if you’ve been told you have a NET related syndrome not listed.

Neuroendocrine Cancer – shh! Can you hear it? 

Thanks for reading

Ronny

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Neuroendocrine Cancer Nutrition Series Article 2 – Gastrointestinal Malabsorption

 

This is the second article in the Neuroendocrine Cancer Nutrition series. In  the first article, I focused on Vitamin and Mineral deficiency risks for patients and there is a big overlap with the subject of Gastrointestinal Malabsorption. Those who remember the content will have spotted the risks pertaining to the inability to absorb particular vitamins and minerals. This comes under the general heading of Malabsorption and in Neuroendocrine Cancer patients, this can be caused or exacerbated by one or more of a number of factors relating to their condition. It’s also worth pointing out that malabsorption issues can be caused by other reasons unrelated to NETs. Additionally, malabsorption and nutrient deficiency issues can form part of the presenting symptoms which eventually lead to a diagnosis of Neuroendocrine Cancer; e.g. in my own case, I was initially diagnosed with Iron Deficiency Anemia in association with some weight loss. Even after diagnosis, these issues still need to be carefully monitored as they can manifest as part of the consequences of having cancer and cancer treatment.

Malabsorption will present via several symptoms which may be similar to other issues (i.e. they could masquerade as, or appear to worsen the effect of a NET Syndrome). These symptoms may include (but are not limited to) tiredness/fatigue/lethargy, stomach cramps, diarrhea, steatorrhea (see below), weight loss. Some of these symptoms could be a direct result of nutrient deficiencies caused by the malabsorption.  Some patients (and perhaps physicians?) could mistake these for symptoms of Neuroendocrine disease including certain syndromes, perhaps leading to prescribing expensive and unnecessary drugs when a different (and cheaper) strategy might be better.

Crash Course……. We eat food, but our digestive system doesn’t absorb food, it absorbs nutrients.  Food has to be broken down from things like steak and broccoli into its nutrient pieces: amino acids (from proteins), fatty acids and cholesterol (from fats), and simple sugars (from carbohydrates), as well as vitamins, minerals, and a variety of other plant and animal compounds. Digestive enzymes, primarily produced in the pancreas and small intestine (they’re also made in saliva glands and the stomach), break down our food into nutrients so that our bodies can absorb them.  If we don’t have enough digestive enzymes, we can’t break down our food—which means even though we’re eating well, we aren’t absorbing all that good nutrition.

What is malabsorption?

The malabsorption associated with Neuroendocrine Cancer is most prevalent with the inability to digest fat properly which can lead to steatorrhea. Patients will recognise this in their stools. They may be floating, foul-smelling and greasy (oily) and frothy looking. Many patients confuse steatorrhea with diarrhea but technically it’s a different issue although both issues may present concurrently. Whilst we all need some fat in our diets (e.g. for energy), if a patient is not absorbing fat, it ends up being wasted in their stools and in addition to the steatorrhea, it can also potentially lead to (unwanted) weight loss and micronutrient deficiencies of the fat-soluble vitamins A, D, E and K. Certain water-soluble vitamins, particularly B3 and B12, are also at risk. Many NET Patients are prescribed a supplement of pancreatic enzymes to combat these issues – see Article 5 in this series – Pancreatic Enzyme Replacement Therapy (PERT).

What causes it with NET Patients?

Structural Changes (i.e. Surgery) 

This can play a very big part in malabsorption issues. For example, if a patient has undergone Pancreatic surgery, this will most likely effect the availability of pancreatic (digestive) enzymes needed to break down food. Many Small Intestine NET (SI NET) patients will suffer due to the removal of sections of their ileum, an area where absorption of water-soluble vitamins and other nutrients take place. In fact, the terminal ileum is really the only place where B12 is efficiently absorbed.  Low B12 is known to cause fatigue.  Some patients with Gastric tumours succumb to pernicious anemia with the most common cause being the loss of stomach cells that make intrinsic factor. Intrinsic factor helps the body absorb vitamin B12 in the intestine. Although a less common tumour location, jejunum surgery could result in loss of nutrients as this section of the small intestine is active in digestive processes. Malabsorption issues for SI NETs are an added complication to the issues caused by a shorter bowel (e.g. faster transit time), something which is regularly assumed to be the effects of one of the NET Syndromes (particularly diarrhea and fatigue), when in actual fact, it’s a simple consequence of cancer treatment and may need a different treatment regime.

Evidence of the problems being caused by the effects of small intestinal surgery can be found in a recently published Swedish study which you can read here: Click here. This particular study recommends supplementation of B12 and D3 for those affected.  If you’re having trouble getting your physician to monitor your vitamin levels, show them these studies. I get these vitamins checked annually.

The Gallbladder and Liver

The Gallbladder plays an important part in the digestive system – particularly in fat breakdown. The liver continually manufactures bile, which travels to the gallbladder where it is stored and concentrated. Bile helps to digest fat and the gallbladder automatically secretes a lot of bile into the small intestine after a fatty meal. However, when the gallbladder is removed, the storage of bile is no longer possible and to a certain extent, neither is the ‘on demand automation’. This results in the bile being constantly delivered/trickled into the small intestine making the digestion of fat less efficient. One of the key side effects of Somatostatin Analogues  (Octreotide and Lanreotide) is the formation of gall stones and many Neuroendocrine Cancer patients have their gallbladder removed to offset the risk of succumbing to these issues downstream. However, the removal of the gallbladder increases the risk of Bile Acid Malabsorption (BAM) as described below. Any issues with Bile Ducts can also have a similar effect.

The Liver has multiple functions including the production of bile as stated above. However, one of its key functions within the digestive system is to process the nutrients absorbed from the small intestine.  If this process is affected by disease, it can potentially worsen the issues outlined above.

Bile Acids Malabsorption

Another risk created by the lack of terminal ileum is Bile Acids Malabsorption (BAM) (sometimes known as Bile Salts Malabsorption and some texts described the resultant diarrhea as ‘Bile Acid Diarrhea”). Bile Acids are produced in the liver and have major roles in the absorption of lipids in the small intestine. Following a terminal ileum resection which includes a right hemicolectomy, there is a risk that excess Bile Acids will leak into the large intestine (colon) via the anastomosis (the new joint between small and large intestines).  This leakage can lead to increased motility, shortening the colonic transit time, and so producing watery diarrhea (or exacerbating an existing condition).

Somatostatin Analogues

Somatostatin Analogues can also impact (or worsen) the ability to digest fat as they inhibit the production of pancreatic digestive enzymes (amongst other things). This is a well-known side effect of both Octreotide and Lanreotide. The levels of the fat-soluble vitamins (ADEK) and B vitamins such as B12, need to be monitored through testing and/or in reaction to symptoms of malabsorption.  If necessary these issues need to be offset with the use of supplements as directed by your dietician or doctor. Supplements are less affected by malabsorption of nutrients but their efficiency can be impacted by fast gut transit times (thus why testing is important).  The evidence and recommendations for malabsorption caused by somatostatin analogues is here: Click Here.  

Overlapping Areas

Deficiencies of these vitamins and certain minerals can lead to other conditions/comorbidities, some more serious than others. For a list of the vitamins and minerals most at risk for Neuroendocrine Cancer patients, have a read of my article which was co-authored by Tara Whyand – Vitamin and Mineral deficiency risks.

There is a third article in this series discussing a related issue with Neuroendocrine Cancer, particularly where gut surgery has been performed. You can link directly to this article here  – “Gut Health” – (Gut Health, Probiotics and Small Intestinal Bacterial Overgrowth (SIBO)).

The fourth article  looks at Amines and why they can cause food reactions or exacerbate syndromes.

Many people also confuse steatorrhea with diarrhea (although these issues can appear simultaneously), again leading to wrong conclusions about the causes and effects, and worryingly, the treatment required. Check out my diarrhea article – click here.

Article 5 in this series looks at how to combat malabsorption caused by pancreatic insufficiency – Pancreatic Enzyme Replacement Therapy (PERT).

My article ‘The Diarrhea Jigsaw’ is complementary to this nutrition series.

Summary

A common problem in patients and from what I see, many just assume this is part of their various syndromes leading to the wrong therapy or no therapy as it’s simply ignored. Again, I remain very grateful to Tara Whyand for some assistance.

This is a big and complex subject and I only intended to cover the basics.  Everyone is different and nothing in here should be accepted as medical advice for you or anyone you know.  If you need professional advice, you should speak to your doctor or registered dietitian.

Thanks for reading

Ronny

I’m also active on Facebook. Like my page for even more news. I’m also building up this site here: Ronny Allan

Disclaimer

My Diagnosis and Treatment History

Most Popular Posts

Sign up for my twitter newsletter

Read my Cure Magazine contributions

Remember ….. in the war on Neuroendocrine Cancer, let’s not forget to win the battle for better quality of life!

patients included

Please Share this post