Genetics and Neuroendocrine Tumors


In my article ‘Ever wonder what caused your NET’, I concluded that currently, the only known scientifically explained causes for NETs were hereditary/genetic in nature.  This is mostly associated with those who have MEN syndromes (yes, they are a syndrome not a type of tumour) and a few other less common types of NET including Pheochomocytoma/Paraganglioma (Pheo/Para) and Medullary Thyroid Carcinoma (MTC) (the familial version of MTC is often referred to as FMTC). However, please note this does not mean that all those diagnosed with pancreatic, parathyroid, pituarity, Pheo/Para and MTC tumours, will have any hereditary or genetic conditions, many will simply be sporadic tumors.

In recent years, it has become increasingly apparent that a number of Neuroendocrine tumours arise as a result of germline genetic mutations and are inherited in an autosomal dominant pattern. The number of genes implicated is increasing.

Apparently, 5-10% of Gastroenteropancreatic NETs (GEP NETs) are estimated to have a hereditary background. Hereditary syndromes associated with these include Multiple Endocrine Neoplasia (MEN), Von Hippel Lindau (VHL), Neurofibromatosis Type 1 (NF1), Tuberous Sclerosis (TS) and others. People who have a genetic condition may present with the tumors (perhaps along with an associated functional hormone syndrome) and so the genetic condition if there is one, may not be known at this point.

genetics locations
Overview of genes with recurrent mutations in NETs and their distribution accordingly to anatomical location. Please note the percentages on the above diagram may differ depending on where you look).  
Citation: European Journal of Endocrinology 174, 6; 10.1530/EJE-15-0972

How will I know if I am affected? 

Some people do worry about this, often because of what they find on the internet including inside patient forums.  I suspect some people already know via family connections and as an example (there are many), I guess if you have 2 tumors found in (say) parathyroid and pancreas, it should at least raise a suspicion for MEN1 and be investigated.

Many people say how do I know, how do I check and this is obviously a delicate subject.  Of course, your first port of call should be your NET specialist if you suspect or know of any connection.

Thus why I was interested in a paper published in Springer Link – titled “When should genetic testing be performed in patients with neuroendocrine tumours.”  When reading, you’ll find it’s actually much more than that! Check it out here:

Crossref DOI link: https://doi.org/10.1007/s11154-017-9430-3

In this review, the authors examined the features which may lead a clinician to suspect that a patient may have an inherited cause of a NET and they outlined which underlying conditions should be suspected. They also discussed what type of screening may be appropriate in a variety of situations. If there is a way to identify which patients are likely to have a germline mutation, this would enable clinicians to counsel patients adequately about their future disease risk, and allows for earlier detection of at-risk patients through family screening. There’s a couple of minor errors in the text but I’ve contacted the authors who also agreed they should have included the pituitary.

The authors focused on presentations of NETs of the gastrointestinal system, chromaffin cell tumours (Pheochromocytoma and Paraganglioma) and Medullary Thyroid Carcinoma. Pituitary tumors (normally associated with MEN1), were not considered in scope for the review.  Interesting thought, the review includes news of a move by endocrinologists to reclassify ‘Pituitary Adenomas’ as Pituitary NETs (PitNETs). Read the abstract here.  This would appear to be in line with a gradual shift from the benign nomenclature associated with certain NETs to the ‘malignant’ potential of these type of tumors.  The abbreviation is also in line with others, e.g. pNET, SiNET, etc.  A useful reminder that we must stop using the term ‘Carcinoid‘ as this is regressing this extremely useful initiative to highlight the malignant potential of all NETs.

There also appears to be some linkage to the study looking at the possibility of familial Small Intestine NETs (SiNETs).  You can read more about a US registered trial here (with apologies for use of the now defunct term ‘Carcinoid‘).

This is a complex subject and the text above is very basic. If you wish to dig further, the quoted reference is a good read.  Just to emphasise, it’s aim is to provide advice about when to recommend genetic testing for NETs, and in doing so provides some useful reference information.  Please also note they are finding new genetic links all the time so there could be some omissions of recently discovered genes but the article remains good enough as a primer on the subject.  It’s broken down into 4 distinct tumor groupings:

1.  Gastroenteropancreatic (GEP NETs)

2.  Bronchial/Thymic NETs

3.  Pheochromocytoma/Paraganglioma  The familial connection with Pheo/Para is complex. Up to 13 genes have been identified including NF1, RET, VHL, SDHA, SDHB, SDHC, SDHD, SDHAF2(SDH5), TMEM127, MAXm EPAS1, FH, MDH2.  Read more here (recent update)The NIH also have a useful section – click here.

4.  Medullary Thyroid Carcinoma

You may also find this article from the National Cancer Institute very useful.  It has a wider scope but a different aim. Genetics of Endocrine and Neuroendocrine Neoplasias (PDQ®)–Health Professional Version”

I also noted the UKINETS Guidelines for NETs has a section on genetics and includes something called Carney Complex.

Thanks for reading

Ronny

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

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Don’t believe the hype – Neuroendocrine Cancer Myths debunked


Don't believe the hype - 10 myths

OPINION.

There’s a lot of inaccurate and out of date information out there.  Some of it is propaganda but most is a combination of misunderstanding and patient forum myth spreading …….

Myth 1:  All Neuroendocrine Tumours are benign

Not trueBy any scientific definition, the word ‘tumour’ means ‘an abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumours may be benign (not cancerous), or malignant (cancerous)’.  Sure, some NETs will be benign.  However, The World Health Organisation (WHO) 2010 classification for digestive system 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.  This has been reinforced in the 2017 update to include clarification for other endocrine organ types of NET including Pheochromocytoma. Read more here.  The word ‘Carcinoid’ is inextricably linked with this issue – read here why we need to stop using the term to help fight the benign myth.

Kunz His belief these tumors did not metastisize

Myth 2:  Neuroendocrine Tumours is a terminal condition

Not true.  By any definition of the word terminal in a medical diagnostic context, most NET patients have a good prognostic outlook, even those with metastatic and incurable variants of the disease. Read more here.

being_there_front
Graphic courtesy of Ellie McDowell

Myth 3: Carcinoid is another word for Neuroendocrine Tumours 

Not true.  Carcinoid is a very old term and was phased out years ago.  Carcinoid is not mentioned in the latest WHO Classification schemes for Neuroendocrine Neoplasms (a term covering Neuroendocrine Tumours and Neuroendocrine Carcinoma). Unfortunately, the problem is exacerbated by organisations and individuals who still use the word.  Also, those who use the following terms:

  • “Carcinoid Neuroendocrine”,
  • “Neuroendocrine Carcinoid”,
  • “Carcinoid and Neuroendocrine”,
  • “Neuroendocrine and Carcinoid”,
  • “Carcinoid NETs” or “CNET”

These are all contextually incorrect and misleading terms (not to mention the bad grammar). ENETS, NANETS and NCCN publications are gradually phasing the word out except in relation to Carcinoid Syndrome (and even then there could be easy solutions for this). Read more here and here.

carcinoid vs neuroendocrine

Myth 4:  All NET patients get ‘carcinoid syndrome’

Not true.  Firstly, many NET cancers are non-functional; and secondly, carcinoid syndrome is only one of a number of “NET Syndromes” associated with the various types of NET. However, the issue is further confused by those who use the word ‘Carcinoid‘ to incorrectly refer to all NETs and use Carcinoid Syndrome to refer to all NET Syndromes.  Read more here.

Early signs of a late diagnosis (2)

Myth 5:  Neuroendocrine Neolasms are rare

Not true.  As a collective grouping of cancers, this is no longer accurate. Read more here.  Also check out my post about the “Invisible NET Patient Population“.

Yao not rare

Myth 6:  Steve Jobs had Pancreatic Cancer

Not true.  Steve Jobs had a Neuroendocrine Tumour of the Pancreas.  Ditto for a few other famous names. Read more here.

steve jobs 2010
The last few years have reminded me that life is fragile

Myth 7:  I’m not getting chemotherapy, I must be doing OK?

Not true.  For some cancers or some sub-types of cancers, although it remains an option, chemotherapy is not particularly effective, e.g. some types of Neuroendocrine Cancer (NETs). In general, well differentiated NETs do not normally show a high degree of sensitivity to chemotherapy, although some primary locations fare better than others. However, many of the treatments for NET Cancer are somewhat harsh, have long-term consequences, and have no visible effects. NET patients are often said to “look well” but that doesn’t mean they are not struggling behind the scenes or under the surface.  Read more here.  P.S. Afinitor (Everolimus), Sutent (Sunitinib) are not chemo – Read more here.

chemotherapy-hand-and-arm

Myth 8:  All diarrhea is caused by carcinoid syndrome

Not true.  It could be one of the other syndromes or tumor types or a side effect of your treatment.  Check out this post.

NETCancer Diarrhea Jigsaw

Myth 9:  Neuroendocrine Tumours is a ‘good cancer’

Not true.  Simply, no cancer is good.  Some are statistically worse than others in prognostic terms, that’s true…… but living with NETs is very often not a walk in the park. However, no one cancer is better to get than any other – they’re all bad.  Read more here.

Good-Bad

Myth 10:  Every NET Patient was misdiagnosed for years

Not true.  Many NET Patients are correctly diagnosed early on in their investigation and in a reasonable time.  This myth is perpetuated because of two things: firstly, on forums, the ratio of long-term misdiagnosis is high creating a false perception; and secondly, the method of capturing patient surveys is not extensive enough – again creating a false perception.  In fact, the latest and largest database analysis from US indicates earlier diagnosis is improving, with more and more NETs being picked up at an early stage. Read more here.

if your doctors dont suspect something

Myth 11:  Somatostatin Analogues are a type of Chemotherapy

Not true.  Somatostatin Analogues (e.g. Octreotide and Lanreotide) are not chemotherapy, they are hormone inhibiting drugs.  They are more biotherapy. As the drugs latch onto somatostatin receptors, they are more targeted than systemic. For the record, Everolimus (Afinitor) and Sunitinib (Sutent) are not chemotherapy either. Read more here.

chemo-or-not-chemo

Myth 12:  Stuart Scott (ESPN) and Audrey Hepburn had Neuroendocrine Cancer. 

Not true. This is a common misunderstanding within the community.  They both had Pseudomyxoma Peritonei (PMP).  Read more about PMP here.

 

 

 

Myth 13:  I’ve been diagnosed with Neuroendocrine Tumours – my life is over

Not true.  Many patients live a very long time and lead fairly normal lives with the right treatment and support. It’s difficult but I try not to use ‘I can’t’ too much. Read more here.

I CAN

Myth 14:  There are only a handful of Neuroendocrine specialists in the world

Not true.  There are many specialists in many countries. Get links to specialists by clicking here.

10 questions to ask your doctor

Myth 15:  The Ga68 PET scan is replacing the CT and MRI scan in routine surveillance for all NET Patients

Not true.  It is actually replacing the Octreotide Scan for particular purposes,  or will eventually.  Read more by clicking here.

PET-CT-Scanner

Myth 16:  All NET Patients are Zebras

Not true.  They are in fact human beings and we should treat them as such. Please don’t call me a zebra and please don’t use the term on my social media sites, I refuse to perpetuate this outdated dogma.

hoofbeats

Myth 17: Multiple Endocrine Neoplasia (MEN) is a type of Neuroendocrine Tumour

Not true. Multiple Endocrine Neoplasia are syndromes and inherited disorders.  You can have MEN and not have any tumours.  However, these disorders can put people at more risk of developing Neuroendocrine or Endocrine Tumours. Read more here

genetics

Myth 18: Palliative Care means end of life or hospice care  

Not true. Palliative care is specialized medical care that focuses on providing patients relief from pain and other symptoms of a serious illness. A multidisciplinary care team aims to improve quality of life for people who have serious or life-threatening illnesses, no matter the diagnosis or stage of disease. Read more here

The P word

Myth 19: Serotonin is found in foods

Not true. Serotonin is manufactured in the body. Read more here

brain-neurotransmitter-serotonin

Myth 20: NETs cannot be cured

Not true. If caught early enough, some NETs can be treated with curative intent (totally resected) with little or no further follow up.  It says this in ENETS and NANETS publications which are authored by our top specialists. If we can’t believe them, who can we believe? Read more here.

cure quote

Myth 21: Pancreatic Enzyme Replacement Therapy (Creon etc) is only for pancreatic patients

Not true. It’s for any patient who is exhibiting exocrine pancreatic insufficiency. Read more here.

PERT

More to follow no doubt

For general cancer myths and the dangers of fake health news, please see my ARTICLE HERE

Thanks for reading

Ronny

Hey Guys, 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!

patients included

wego blog 2018 winner