Neuroendocrine Neoplasms (NEN) – benign vs malignant

Kunz His belief these tumors did not metastisize

OPINION:

One of the most controversial aspects of Neuroendocrine Neoplasms, in particular low grade Neuroendocrine Tumours (NETs), is the ‘benign vs malignant’ question.  It’s been widely debated and it frequently patrols the various patient forums and other social media platforms. It raises emotions and it triggers many responses ….. at least from those willing to engage in the conversation. At best, this issue can cause confusion, at worst, it might contradict what new patients have been told by their physicians (….or not been told). I don’t believe it’s an exact science and can be challenging for a NET specialist let alone a doctor who is not familiar with the disease.

NANETS Guidance talks about the ‘…heterogeneous clinical presentations and varying degrees of aggressiveness‘ and ‘…there are many aspects to the treatment of neuroendocrine tumours that remain unclear and controversial‘.  I’m sure the ‘benign vs malignant’ issue plays a part in these statements.

In another example, ENETS Guidance discusses (e.g.) Small Intestine Tumours (Si-NETs) stating that they ‘derive from serotonin-producing enterochromaffin cells. The biology of these tumors is different from other NENs of the digestive tract, characterized by a low proliferation rate [the vast majority are grade 1 (G1) and G2], they are often indolent’.  However, they then go on to say that ‘Si-NETs are often discovered at an advanced disease stage – regional disease (36%) and distant metastasis (48%) are present‘.  It follows that the term ‘indolent‘ does not mean they are not dangerous and can be ignored and written off as ‘benign’. This presents a huge challenge to physicians when deciding whether to cut or not to cut.

Definitions

To fully understand this issue, I studied some basic (but very widely accepted) definitions of cancer.  I also need to bring the ‘C’ word into the equation (Carcinoid), because the history of these tumours is frequently where a lot of the confusion lies.  The use of the out of date term by both patients, patient advocates and doctors exacerbates the issue given that it decodes to ‘carcinoma like‘ which infers it is not a proper cancer.  See more below.

Let’s look at these definitions provided by the National Cancer Institute.  Please note I could have selected a number of organisations but in general, they all tend to agree with these definitions give or take a few words. These definitions help with understanding as there can be an associated ‘tumour’ vs ‘cancer’ debate too.

Cancer – Cancer is the name given to a collection of related diseases. In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues. There are more than 100 types of cancer which are usually named for the organs or tissues where the cancers form.  However, they also may be described by the type of cell that formed them.

Author’s note: The last sentence is important for Neuroendocrine Tumour awareness (i.e. Neuroendocrine Tumour of the Pancreas rather than Pancreatic Cancer).

Carcinoma – Carcinomas are the most common grouping of cancer types. They are formed by epithelial cells, which are the cells that cover the inside and outside surfaces of the body. There are many types of epithelial cells, which often have a column-like shape when viewed under a microscope.

Author’s note: By definition, Carcinomas are malignant, i.e. they are without question malignant cancers. Poorly differentiated Neuroendocrine Neoplasms are deemed to be a ‘Neuroendocrine Carcinoma’ according to the most recent World Health Organisation (WHO) classification of Neuroendocrine Tumours (2017) and ENETS 2016 Guidance. You will have heard of some of the types of Carcinoma such as ‘Adenocarcinoma’ (incidentally, the term ‘Adeno’ simply means ‘gland’). It follows that Grade 3 Neuroendocrine Carcinomas (NEC) are beyond the scope of this discussion.

Malignant – Cancerous. Malignant cells can invade and destroy nearby tissue and spread to other parts of the body.

Benign – Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body.

Author’s Note: This is a key definition because there are people out there who think that low grade NETs are not cancer. 

Tumour (Tumor) – An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called Neoplasm.

Author’s Note: Neoplasm is an interesting term as this is what is frequently used by ENETS and NANETS in their technical documentation, sometimes to cover all Neuroendocrine types of cancer (Tumor and Carcinoma). It follows that a malignant tumour is Cancer. The term “Malignant Neuroendocrine Tumour” is the same as saying “Neuroendocrine Cancer”

Neuroendocrine Tumours – Benign or Malignant?

Definitions out of the way, I have studied the ENETSUKINETS and NANETS guidance both of which are based on internationally recognised classification schemes (i.e. the World Health Organisation (WHO)).

In older versions of the WHO classification schemes (1980 and 2000), the words ‘benign’ and ‘uncertain behaviour’ were used for Grades 1 and 2. However, the 2010 edition, the classification is fundamentally different (as is the recent 2017 publication).  Firstly, it separated out grade and stage for the first time (stage would now be covered by internationally accepted staging systems such as TNM – Tumour, (Lymph) Nodes, Metastasis). Additionally, and this is key to the benign vs malignant discussion, the WHO 2010 classification is based on the concept that all NETs have malignant potential.  Here’s a quote from the UKINETS 2011 Guidelines (Ramage, Caplin, Meyer, Grossman, et al).

Tumours should be classified according to the WHO 2010 classification (Bosman FT, Carneiro F, Hruban RH, et al. WHO Classification of Tumours of the Digestive System. Lyon: IARC, 2010). This classification is fundamentally different from the WHO 2000 classification scheme, as it no longer combines stage related information with the two-tiered system of well and poorly differentiated NETs. The WHO 2010 classification is based on the concept that all NETs have malignant potential, and has therefore abandoned the division into benign and malignant NETs and tumours of uncertain malignant potential.

The guidance in 2017 WHO reinforces this statement to include endocrine organs, including the pancreas and adrenal glands.

The C Word (Carcinoid) – part of the problem?

History lesson – Carcinoid tumours were first identified as a specific, distinct type of growth in the mid-1800’s, and the name “karzinoide” was first applied in 1907 by German pathlogist Siegfried Oberndorfer in Europe in an attempt to designate these tumors as midway between carcinomas (cancers) and adenomas (benign tumors).

The word ‘Carcinoid’ originates from the term ‘Carcinoma-like’.  ‘CARCIN’ is a truncation of Carcinoma. ‘OID’ is a suffix used in medical parlance meaning ‘resembling’ or ‘like’.  This is why many people think that Carcinoid is not a proper cancer.

The situation is made even more confusing by those who use the term “Carcinoid and Neuroendocrine Tumors” inferring that it is a separate disease from the widely accepted and correct term ‘Neuroendocrine Tumor’ or Neuroendocrine Neoplasm.  A separate discussion on this subject can be found in this post here. I encourage you to stop using the term ‘Carcinoid’ which is just perpetuating the problem. 

Kunz His belief these tumors did not metastisize

How are NENs Classified?

If you read any NET support website it will normally begin by stating that Neuroendocrine Tumours constitute a heterogeneous group of tumours. This means they are a wide-ranging group of different types of tumours.  However, the latest WHO classification scheme uses the terms ‘Neuroendocrine Tumour’ for well differentiated Grade 1 (low-grade), Grade 2 (Intermediate Grade) and Grade 3 (High Grade) NET; and ‘Neuroendocrine Carcinoma’ (NEC) for  poorly differentiated tumours which are by default grade 3 or high grade. They also use the term ‘Neoplasm’ to encompass all types of NET and NEC. So Grade 1 is a low-grade malignancy and so on (i.e any grade of NET is a malignant tumour).  You may benefit from reading my blog article on Staging and Grading of NETs as this is also a poorly understood area.

Can some NETs be Benign?

By any accepted definition of cancer terms, a tumour can be non-cancerous (benign) or cancerous (malignant).  This is correct for any cancer type. For example, the word is used in the 2016 version of Inter Science Institute publication on Neuroendocrine Tumors, a document I frequently reference in my blog.  For example, I’ve seen statements such as “These tumors are most commonly benign (90%)” in relation to Insulinoma (a type of Pancreatic NET or pNET). Ditto for Pheochromocytoma (an adrenal gland NET).  Adrenal and Pituitary ‘adenomas’ are by definition benign (adenoma is the benign version of Adenocarcinoma).  And I note that there is a ‘benign’ code option for every single NET listed in the WHO International Classification of Diseases (ICD) system.

The ‘BUT‘ is this – all WHO classification systems are based on the concept that NETs always have malignant potential.  The WHO 2017 classification update confirmed this thinking by adding endocrine organs including the pancreas and adrenal glands.

don't worry it's benign widescreen

Can Tumours be Malignant or become Malignant?

Using the definition above, if a tumour invades and destroy nearby tissue and spread to other parts of the body, then it’s malignant (i.e  Cancer). However, there’s a reason why the WHO declared in 2010 that all NETs have malignant potential (as amplified in WHO 2017). It may not happen or it may happen slowly over time but as Dr Richard Warner says, “they don’t all fulfill their malignant potential, but they all have that possible outcome”.  Thus why ongoing surveillance is important after any diagnosis of Neuroendocrine Tumour of any grade or at any stage.  Dr Lowell Anthony, a NET Specialist from the University of Kentucky explains this much better than I can – CLICK HERE to hear his two-minute video clip.  This issue even caused confusion with doctors, some of whom still think a Stage 4 NET is still benign. Not only is this very insensitive to the patient concerned but it also goes against all the definitions of ‘benign’ and ‘malignant’ that exist in authoritative texts.

Summary

This was a difficult piece of research. I do believe there are scenarios where NETs will be benign and probably never cause the person any real harm (e.g. many are found on autopsies). I  suspect this is the same for many cancers. However, based on the above text and the stories of people who have presented for a second time but with metastatic disease, use of the word ‘benign’ is probably best used with great care.

I would certainly (at least) raise an eyebrow if someone said to anyone with any NET tumour, “you don’t need any treatment or surveillance for a NET”; or “it has been cured and no further treatment or surveillance is required”.  Particularly if they are not a NET specialist or a recognised NET Centre.

Remember, I’m not a medical professional, so if you are in any doubt as to the status of your NET, you should discuss this directly with your specialist.  A good place to start is evidence of your Grade, Differentiation, Primary Site Location and Stage.

You may be interested in reading these associated posts:

Carcinoid vs Neuroendocrine

Neuroendocrine Neoplasms – Grading and Staging (WHO 2017)

Incurable vs Terminal

10 Questions for your doctor

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

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

Ronny Allan is an award winning patient leader and advocate for Neuroendocrine Cancer.


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I bet my flush beats yours?

royal_flush_w
There are different types of flush!

Neuroendocrine Cancers can sometimes present with one or more vague symptoms which occasionally results in a lengthy diagnostic phase for some.  Sure, there can be issues with doctor experience and knowledge that can add to the problem. However, some people do present with multiple vague and confusing symptoms and some people have comorbidities which have similar symptoms.  Textbook diagnostics just don’t make sense, sometimes even when the doctor suspects Neuroendocrine Cancer i.e. classic symptoms of ‘something’ but with negative markers for NETs. Clearly those are extreme cases and just like other complex diseases, many diagnoses of Neuroendocrine Cancer can be extremely challenging.  Even for an experienced doctor, it can be a difficult jigsaw!

Most types of Neuroendocrine Cancer can be accompanied by a ‘syndrome’ i.e. the tumours are ‘functional’ and this is normally (but not always) associated with metastatic disease. At this point it’s also worthwhile saying that some Neuroendocrine Cancers can be ‘silent’ (non-functional) for years before any symptoms show and it’s normally only when they metastasize, that these clinical syndromes come to life. Ironically, the manifestation of the disease with a syndrome can occasionally turn out to be a life saver albeit the cancer is normally incurable at this stage – but still treatable.

The most common type of Neuroendocrine Cancer can often present as a collection of symptoms known as Carcinoid Syndrome and the most common of these is flushing with approximately 84% frequency.  Others symptoms include (but are not limited to) diarrhoea, heart palpitations, stomach cramps and general abdominal pain/discomfort, shortness of breath, wheezing.  You can see the scope for confusion and misdiagnosis.  You may find my blog on the ‘5 E’s of Carcinoid Syndrome’ useful.

When you look at these general Carcinoid Syndrome symptoms, flushing seems to be the one that stands out as a ‘cardinal sign’ whereas many others are vague and easily confused with common/regular illnesses.  However, the flushing is reported to be different from most people’s perceptions of a ‘flush’.  The Carcinoid flush is almost always ‘dry’.  To quote my ‘amazing yellow book‘ (co-authored by Woltering, Vinik, O’Dorisio et al), “…. a good rule of thumb is if the flushing is wet (accompanied by sweating), it is due to a cause other than Carcinoid”.   Dr James Yao, another well known NETs guru also raises this distinction by stating…. “The facial flushing of carcinoid syndrome is usually a dry flushing, and not associated with sweating like other kinds of flushing. The flushing is often a symptom that others notice before patients do. They may not feel it themselves.”

Additionally, from the same source, there appears to be at least two varieties of flushing in Carcinoid Syndrome related to two different anatomical regions of the primary tumour (again a useful guide from my amazing yellow book):

What to Look For in Flushing – Distinguishing Signs and Symptoms

There are two varieties of flushing in carcinoid syndrome:
1. Midgut: The flush usually is faint pink to red in color and involves the face and upper trunk as far as the nipple line. The flush is initially provoked by alcohol and food containing tyramine (e.g., blue cheese, chocolate, aged or cured sausage, red wine). With time, the flush may occur spontaneously and without provocation. It usually lasts only a few minutes and may occur many times per day. It generally does not leave permanent discoloration.

2. Foregut tumors: The flush often is more intense, of longer duration, and purplish in hue. It is frequently followed by telangiectasia and involves not only the upper trunk but may also affect the limbs. The limbs may become acrocyanotic, and the appearance of the nose resembles that of rhinophyma. The skin of the face often thickens, and assumes leonine facies resembling that seen in leprosy and acromegaly.

Another source for flush descriptions comes from a paid article written by well known NET Endocrinologist – Kjell Öberg.

Four different types of flushing have been described in the literature.
Endocrinology: Adult and Pediatric – 7th Edition 2016.

The first type is the diffuse, erythematous flush, usually affecting the face, neck, and upper chest (i.e., normal flushing area). This flush is commonly of short duration, lasting from 1 to 5 minutes, and is related to early stages of malignant midgut NETs.

The second type is violaceous flush, which affects the same areas of the body and has roughly the same time course or sometimes lasts a little longer. These patients also may have facial telangiectasia. This flush is related to the later stages of malignant midgut NETs and is normally not felt by the patients because they have become accustomed to the flushing reaction.

The third type is prolonged flushing, lasting for hours up to several days. It sometimes involves the whole body and is associated with profuse lacrimation, swelling of the salivary glands, hypotension, and facial edema. These symptoms are usually associated with malignant bronchial carcinoids.

Finally, the fourth type of flushing reaction is bright red, patchy flushing, which is seen in patients with chronic atrophic gastritis and ECLomas (derived from enterochromaffin-like cells) of the gastric mucosa with evidence of increased histamine production.

Differential diagnoses for flushing?

The facial flushing associated with NETs should be distinguished from other causes of flushes. The carcinoid syndrome flush is provoked by spicy food, alcohol, and physical and psychological stress, and it is often worse in the morning. Patients with idiopathic flushes usually have a long history of flushing, starting rather early in life and sometimes with a family history without occurrence of a tumor. Menopausal flushes usually involve the whole body and might be related to release of calcitonin gene–related peptide (CGRP) with transient vasodilation, a so-called dry flush. Another type of menopausal symptom is the wet flush, which includes epinephrine-induced sweating. Proposed mediators of flushing in menopause are CGRP, histamine, prostaglandins, serotonin, lysyl-bradykinin, and substance P. Estrogen is known to have an impact on the production and release of different signaling substances such as noradrenaline and β-endorphin. Low estrogen levels cause lower β-endorphin activity, which in turn enhances the release of gonadotropin-releasing hormone (GnRH), which gives rise to high luteinizing hormone (LH)levels. Postmenopausal women in whom a true carcinoid syndrome is developing can tell the difference between the two types of flushes. Sometimes patients with medullary thyroid carcinoma have brief flushes provoked by alcohol. In patients with watery diarrhea, hypokalemia, achlorhydria syndrome (WDHA; vasoactive intestinal peptide [VIP]omas), a purple-red constant flushing of the whole body may develop. This flushing reaction is related to the vasodilator effects of VIP. Flushes seen in mastocytosis are related to release of histamine from mast cell granules. Mastocytosis is a rare disease of mast cell proliferation that occurs both cutaneously and systemically.

So it’s clear from our experts that the flushing symptom has many potential triggers and can be attributed to the secretion of excess hormones associated with Neuroendocrine Tumours. It’s also clear that the symptom is not just associated with carcinoid syndrome. Although many people focus on serotonin as the main culprit, there appears to be significant evidence to suggest that other hormones may be playing a bigger part with this symptom, e.g. histamine (particularly foregut), tachykinins (Substance P), bradykinins, and prostaglandins.

If you study the online forums, there are frequent questions about flushing, particularly from those looking for a diagnosis and are suspecting Carcinoid Syndrome due to a flushing symptom. However…… even flushing cannot always be attributed to a NET, particularly if it’s the only symptom being presented.

Flushing tests

This is a very useful table taken from my amazing yellow book which gives the tests required to determine the potential source of a flushing (differential diagnosis).  I strongly suspect this is not an exact science (…..is anything in medicine?) but it’s extremely useful.  Personally I would have included Rosacea :-).  The referenced article “>Endocrinology: Adult and Pediatric – 7th Edition 2016 by Öberg, Grosssman et al, generally agrees with this list but adds WHDA Syndrome (a pNET called VIPoma), food, drugs, ethanol and idiopathic. It also generalises Neurologic disorders (see more below).

Öberg, Grosssman, et al list the following drugs that can cause flushes:

  • Bromocriptine
  • Tamoxifen
  • Nicotinic Acid
  • Opiates
  • Calcium channel blockers
  • Ketoconazole
  • Chlorpromazine
  • Cephalosporin

Öberg, Grosssman, et al list the following foods that can cause flushes:

  • Spicy food
  • Glutamate
  • Sodium nitrate
  • Sulfites
  • Hot beverages

Öberg, Grosssman, et al also list the following neurologic disorders that can cause flushes:

  • Anxiety
  • Migraine
  • Parkinson’s disease
  • Spinal cord lesions
  • Brain tumors

Clearly these lists are those that can cause a flush but not everyone will experience this.  For example, when I was syndromic with flushing, I never had any issues with hot beverages.

My own experience with flushing brings back some memories and it emphasises something I say a lot – the patient has a big part to play in their own diagnosis.  Please check out this 90 second video about how I did not play my part!  I was experiencing a mild and innocuous flushing sensation for some months before I was diagnosed with metastatic Neuroendocrine Cancer.  Even though I knew it was weird and something I hadn’t experienced before, I totally ignored it.  I failed to mention it at any of my routine GP appointments or my annual asthma clinic.  I failed to mention it to my specialist who was investigating a GP/PCP diagnosis of Iron Deficiency Anemia/weight loss.  After a CT scan, the specialist appeared to be scratching his head …..  at that point he knew I had cancer but he also knew it was unusual.  I suddenly mentioned the flushing and ‘bingo’.  It was the face of a man who had just found a missing piece of a jigsaw and he correctly predicted the output from my subsequent liver biopsy.

For the next few months, I was keeping my condition private at work but it was sometimes difficult to disguise the flushing. At least  one person thought my blood pressure was going up! Fortunately, my flushing disappeared after treatment.

I’ll complete this post with an interesting summary from an online forum post in which I was participating. There was a general discussion about the severity of ‘syndrome symptoms’ including triggers and I was staggered to read that people were experiencing flushing whilst carrying out routine day-to-day tasks. I’m so happy I don’t flush when I eat one square of chocolate (that would be a complete disaster!).  The one which caught my attention was the simple act of washing hair. Whilst I initially raised my eyebrows and laughed, it did make me think back to the last flush I experienced (and touch wood it was the last …..).  Following my diagnosis, I commenced daily injections of Octreotide. These injections reduced the flushing but it didn’t eliminate it. However, after my ‘debulking’ surgery in Nov 2010, my flushing disappeared.  However, I do remember this small flush coming out of nowhere whilst I was recovering in hospital after that surgery. I was cleaning my teeth and I do vividly remember this minor task taking some effort!

I haven’t had a flush since and if this symptom comes back, I’ll know I have a new problem to contend with.

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

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My Diagnosis and Treatment History

Most Popular Posts

Sign up for my twitter newsletter

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

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