Subscribe to Blog via Email
Neuroendocrine Cancer Nutrition Series Article 2 – Gastrointestinal Malabsorption 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 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. Bile impairment may also contribute. 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 potentially have an effect on 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 takes 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.
Small intestine NETs – Does the length of small intestine resection make a difference?
Short answer – yes. The length of the small intestine removed may produce both problems (diarrhea and steatorrhea). e.g. Large ileal resections (>100 cm) can lead to luminal bile salt deficiency resulting in fat malabsorption and colonic secretion caused by hydroxy fatty acids. Shorter ileal resections (< 100 cm) may cause diarrhea as a result of stimulation of colonic secretion by unabsorbed bile salts. By binding intestinal bile salts, oral cholestyramine (4 g four times a day) may control this type of diarrhea. The fat malabsorption caused by longer ileal resections may react to pancreatic enzyme replacement therapy (PERT) e.g. creon, nutrizym etc. It is also thought that somatostatin analogues could potentially exacerbate fat malabsorption as they are known to inhibit digestive enzymes. Although technically fat malabsorption caused by pancreatic enzyme insufficiency is related to fatty acids rather than bile acids (see below for bile issues).
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). Patients with mild to moderate bile acid malabsorption present with watery diarrhea and generally respond very well to treatment with bile acid binders such as cholestyramine. Patients with more severe bile acid malabsorption have both diarrhea and steatorrhea.
The elephant in the room? 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 and is mentioned in both package insert leaflets as a potential side effect. If somatostatin analogues were the only causal effect, then it shouldn’t be a huge issue but combined with the other potential trouble spots above, use of this drug might tip a person into a pancreatic exocrine deficiency.
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.
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)).
Article 5 in this series looks at how to combat malabsorption caused by pancreatic insufficiency – Pancreatic Enzyme Replacement Therapy (PERT)
Article 6 – featuring Tara Whyand
A number of fantastic short videos covering a wide range of diet and nutrition issues experienced by NET patients. click here
My article ‘The Diarrhea Jigsaw‘ is complementary to this nutrition series. 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. Many people (too many) just blame carcinoid syndrome which is an easy answer but way way off beam. Check out my diarrhea article – click here.
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.
I am not a doctor or any form of medical professional, practitioner or counsellor. None of the information on my website, or linked to my website(s), or conveyed by me on any social media or presentation, should be interpreted as medical advice given or advised by me.
Neither should any post or comment made by a follower or member of my private group be assumed to be medical advice, even if that person is a healthcare professional.
Please also note that mention of a clinical service, trial/study or therapy does not constitute an endorsement of that service, trial/study or therapy by Ronny Allan, the information is provided for education and awareness purposes and/or related to Ronny Allan’s own patient experience. This element of the disclaimer includes any complementary medicine, non-prescription over the counter drugs and supplements such as vitamins and minerals.
Top 10 Posts & Pages in the last 48 hours (auto updates) (Click the titles to read them)
Thanks for reading.
Sign up for my newsletters – Click Here
Check out my Glossary of Terms – click here
Please Share this post for Neuroendocrine Cancer awareness and to help another patient
There has been controversy about the utility of Chromogranin A for many years now. Specialists have been critical about its use but to be fair
UPDATE – Sep 25th, 2023 – Novartis radioligand therapy Lutathera® demonstrated statistically significant and clinically meaningful progression-free survival in first line advanced gastroenteropancreatic neuroendocrine tumors
Whenever I get a chance to talk to a pharma involved in somatostatin analogue injection devices, I tell them one very important thing …… “To
Update August 2023. Latest CT surveillance scan reports “No evidence of progressive disease at any site”. Very pleased! With incurable but treatable cancers such as
US singer-songwriter Jimmy Buffett, best known for his 1970’s hit Margaritaville, has died aged 76. “Jimmy passed away peacefully on the night of September 1
A cup of tea
I would also mention those who contributed to my “Tea Fund” which resides on PayPal. You don’t need a PayPal account as you can select a card but don’t forget to select the number of units first (i.e. 1 = £4, 2 = £8, 3 = £12, and so on), plus further on, tick a button to NOT create a PayPal account if you don’t need one. Clearly, if you have a PayPal account, the process is much simpler
Through your generosity, I am able to keep my sites running and provide various services for you. I have some ideas for 2023 but they are not detailed enough to make announcements yet.
This screenshot is from every single post on my website and depending on which machine you are using, it will either be top right of the post or at the bottom (my posts are often long, so scroll down!)