Neuroendocrine Cancer: Ga68 PET Scan – a game changer?

When I was offered my very first Ga68 PET/CT at a 6 monthly surveillance meeting in May 2018, I was both excited and apprehensive. Let me explain below why I had a mix of emotions.

I was diagnosed in 2010 with metastatic NETs clearly showing on CT scan, the staging was confirmed via an Octreotide Scan which in addition pointed out two further deposits above the diaphragm (one of which has since been dealt with). In addition to routine surveillance via CT scan, I had two further Octreotide Scans in 2011 and 2013 following 3 surgeries, these confirmed the surveillance CT findings of remnant disease. The third scan in 2013 highlighted an additional lesion in my thyroid (still under a watch and wait regime, biopsy inconclusive but read on….).

To date, my 6 monthly CT scans seem to have been adequate surveillance cover and all my tumour and hormone markers remain normal. I’m reasonably fit and well for a 62-year-old.

Then I ventured into the unknown

this is not actually my scan!

I wrote a comprehensive post about the Ga68 PET entitled “…. Into the unknown” – so named because that is how I felt at the time. It’s well-known that the Ga68 is a far superior nuclear scan to the elderly Octreotide type, showing much greater detail with the advantage of providing better predictions of PRRT success if required downstream. It has been a game changer for many and if you look below and inside my article, you will see statistics indicating just how it can ‘change the game’ in somatostatin receptor positive Neuroendocrine Cancer diagnostics and treatment.

The excitement of the Ga68 PET

I was going to get the latest ‘tech’ and thought it could be useful confirmation of what I already knew. I also felt lucky to get one, they are limited in UK and there has to be a clinical need to get access. I was excited because it might just rubber stamp the stability I’ve enjoyed for the past 5 or so years since my last surgery in 2012.

The apprehension of the Ga68 PET

I also felt apprehensive because of the ‘unknown’ factor with cancer, i.e. what is there lurking in my body that no-one knows about, and which might never harm me but this scan will light it up demanding attention. I was also apprehensive in case this more detailed scan found something potentially dangerous. As we know, NETs are mostly slow-growing but always sneaky. Of course, any new tumours found may not actually be new, they were just not seen until the Ga68 PET was able to uncover them.  How annoying!

Is the Ga68 PET Scan a game changer?

To confirm the advantages of SSTR PET over Octreotide scans, a study comprising 1,561 patients reported a change in tumour management occurred in over a third of patients after SSTR PET/CT even when performed after an Octreotide scan.

  • Overall, change in management occurred in 44% (range, 16%-71%) of NET patients after SSTR PET/CT.
  • In 4 of 14 studies, SSTR PET/CT was performed after an 111In-Octreotide scan. In this subgroup, additional information by SSTR PET/CT led to a change in management in 39% (range, 16%-71%) of patients.
  • Seven of 14 studies differentiated between inter- and intramodality changes, with most changes being intermodality (77%; intramodality, 23%). (note: intermodality means changes within the same treatment, intramodality means change to another treatment).

In an older study, this slide from a NET Research Foundation conference shows some more interesting statistics:

wp-image-991783422jpg
This slide from a recent NET Research Foundation conference confirms the power of more detailed scanning

Was Ga68 PET a game changer for me?

Yes, I believe so.  I’m now in the ‘bone met club’ and although that single metastasis has probably been there for some time, it’s not a ‘label‘ I was keen to add to my portfolio. If I was to be 100% honest, I’m not totally convinced it’s a metastasis. The scan has brought more light onto my thyroid issue.  In fact it indicate even more potential issues above the diaphragm including what looks like a new sighting around my left pectoral.  The can also lghts up a known issue in the left clavicle lymph nodes, first pointed out via Octreotide scan in 2010 and biopsy negative.

In addition to a nuclear scan update (routine surveillance), it also formed part of an investigation into progression of my retroperitoneal fibrosis (initially diagnosed 2010 but potential growth spotted on recent surveillance CT).  The Ga68 PET doesn’t make fibrosis light up (it’s not cancerous) but there are some hotspots in the area of the aorta close to the fibrosis.   Surgery is on hold for now as my kidney function is fine following a renal MAG3 scan which reported no blockages. 

It would appear I’m no longer a boring stable patient

The Ga68 PET Scan confirmed:

Bone Metastases. Report indicates “intense focal uptake“. It always amazes me that people can be thankful for having an extra tumour.  I’m thankful I only have a single bone metastasis (right rib number 11). I had read so many stories of those who got their first Ga68 PET and came back with multiple bone metastases. I’ll accept one and add to my NET CV. I have no symptoms of this bone metastasis and it will now be monitored going forward. I’m annoyed that I don’t know how long it’s been there though!

Confirmation and better understanding of the following:

  1. Thyroid lesion There is some uptake showing. A 2014 Biopsy of this lesion was inconclusive and actual 2018 Ga68 PET report infers physiological uptake. I’m already diagnosed hypothyroidism, possibly connected.  (Edit – on ultrasound in Jan 2019, looks slightly smaller than previous check).
  2. Left Supraclavicular Fossa (SCF) Nodes lighting up “intense uptake“.  I’ve had an exploratory biopsy of the SCF nodes, 5 nodes removed negative. Nothing is ‘pathologically enlarged’ in this area. Monitored every 6 months on CT, annually on ultrasound.  I had 9 nodes removed from the left axillary in 2012, 5 tested positive for NETs and this area did not light up. This whole area on the left above the diaphragm continues to be controversial. My surgeon once said I had an unusual disposition of tumours.  (Edit: Nothing sinister or worryingly enlarged showing on Jan 2019 ultrasound – measuring 6mm).
  3. Report also highlights left subpectoral lymph nodes which is new.  The subpectoral area is very interesting as from my quick research, they are closer to the left axillary (armpit) nodes than they are to the SCF nodesI’m hoping to get an ultrasound of these in January at my annual thyroid clinic (Edit: nothing sinister showing on ultrasound in Jan 2019).
  4. My known liver metastases lit up (remnant from liver surgery 2011) – not marked as intense though. The figure of 3 seems to figure highly throughout my surveillance scans although the PET report said “multiple” and predominately right-sided which fits.
  5. Retroperitoneal area. This has been a problem area for me since diagnosis and some lymph nodes are identified (intense word not used). This area has been highlighted on my 3 octreotide scans to date and was first highlighted in my diagnosis trigger scan due to fibrosis (desmoplasia) which was surrounding the aorta and inferior venous cava, some pretty important blood vessels. I wrote an article on the issue very recently – you can read by clicking here. So this scan confirms there are potentially active lymph nodes in this area, perhaps contributing to further growth of the fibrosis threatening important vessels – read below.

Retroperitoneal Fibrosis (Desmoplasia)

I have learned so much about desmoplasia since this issue arose that I now fully understand why I had to have radical surgery back in 2010 to try to remove as much of the fibrosis as possible from the aortic area. You can read more about this in my article.  Desmoplasia via fibrosis is still very much of an unknown and mystery condition in NETs.

I now know that my fibrosis is classed as clinically significant and according to the Uppsala study of over 800 patients inside my article, I’m in 5% of those affected in this way (2% if you calculate it using just the retroperitoneal area).

It appears this problem has come back with new fibrosis or growth of existing fibrosis threatening to impinge on blood vessels related to the kidneys and also my ureters (kidney to bladder urine flow). The Ga68 PET doesn’t make fibrosis light up (it’s not cancerous) but there are some hotspots in the area of the aorta close to the fibrosis.

I didn’t expect this particular problem to return – it was a bit of a shock. My hormone markers have been normal for 8 years and this just emphasises the importance of scans in surveillance. 

Conventional Imaging is still important though

There’s still quite a lot of hype surrounding the Ga68 PET scan and I get this.  However, it does not replace conventional imaging (CI) such as CT and MRI scans which still have their place in routine surveillance and also in diagnostics where they are normally at least the trigger for ‘something is wrong’. For the vast majority, a CT/MRI scan will find tumours and be able to measure reductions and progress in regular surveillance regimes. There are actually recommended usages for the Ga68 PET scan here.  For example, it is not recommended for routine surveillance in place of CI.

In fact, the retroperitoneal fibrosis has appeared on every CT scan since diagnosis but the changes were highlighted on my most recent standalone CT and it triggered the Ga68 PET (although my new Oncologist did say I was due a revised nuclear scan).  It’s not a ‘functional’ issue (although it is caused by functional tumours). In fact the fibrosis is not mentioned on the Ga68 PET because it is not lighting up – but the lymph nodes surrounding it are mentioned and they are under suspicious as being active.

Read a summary of all conventional scans and nuclear scans by clicking here.

Next Steps

I’ve since has meetings with my Oncologist and Surgeon and a treatment plan is underway. My surgeon explained it all in his wonderfully articulate and brilliant surgical mind. Fortunately it’s not really urgent but pre-emptive treatment may be required at some point as the consequences of kidney/bladder function are quite severe. Following some further checks, the anticipated surgery is on hold for now as my kidney function is fine following a renal MAG3 scan which reported no blockages.  I continue to have monthly renal blood tests and it was hinted another renal MAG3 could be done at the end of the year.

Summary

My game has changed, that’s for sure. I’m now entering a new phase and I’m waiting on details of my revised surveillance regime. However, at least my medical team and I now know what WE are dealing with and the risks vs benefits are currently being assessed. I’m heavily involved in that.

If you can see it, you can detect it. If you can detect it, you can monitor or treat it.

Gallium 68 PET Scans – Into the Unknown

OPINION

Cancer is a growth industry …literally! More people are being diagnosed than ever before. Fortunately, more people are surviving than ever before. This is against a backdrop of better awareness, better screening in the big population cancers, and to a certain extent better diagnostic tools, all of which is leading to earlier diagnosis.

So how does this affect Neuroendocrine Cancer?

According to the latest SEER database figures for Neuroendocrine Cancer, one reason for the 7 fold increase in incidence rates since the 1970s is all of those things above including better diagnostics. This has led to a revised set of epidemiological information in many countries that have made the effort to accurately update their cancer registries and there are consistent reports of incidence rates way beyond the recognised rare thresholds. Another piece of good news is that the increase in NET incidence is also due to earlier diagnosis. To sum that up – NETs is also a growth industry.

Better diagnostics

Combined with more awareness and education (including the important pathologists), more NETs than ever are being found, and many found earlier. However, it’s not party time yet because there remains far too many misdiagnoses due to the low population of the disease and the difficulty in diagnosing it. I want to focus on scanning (thus the title of the article). Whilst there are really important factors involved in a diagnosis, such as tumor and hormone markers, and biopsies (tissue is the issue), a scan is very frequently what triggers many deeper investigations to unearth a NET, i.e. if you can see it, you can normally detect it (whatever the ‘it’ is). And I include the widespread availability and increasing advances in endoscopy/ultrasounds/cameras which have also been instrumental in picking up many Gastrointestinal NETs.

The Gallium 68 PET Scan

There’s a lot of excitement about the Gallium 68 PET Scan since it was approved by the US FDA. It’s not new though and has been in use in several countries for some time. It’s a ‘nuclear scan’ and can often form part of what is known as a ‘Theranostic Pair’ (i.e. in conjunction with a therapy – read more here).

What does it do?

It comprises two main components – a PET scanning machine, and the use of a diagnostic imaging agent which is injected into the person undergoing the scan. Most machines have an inbuilt CT which forms part of the scan. The agent is a somatostatin analogue labeled radionuclide (Gallium 68) and basically the PET will then be used to see where the peptide/radionuclide mix ‘loiters’ (i.e. where there are concentrations of somatostatin receptors (SSTR) normally indicating ‘focal intense abnormality‘ of the type that is regularly found with NETs.

Imaging Agents. There are different agent variants, namely, DOTATATE, DOTATOC and DOTANOC. In USA, you may sometimes see this referred as NETSPOT which is more of a commercial label for the agent (NETSPOT is a DOTATATE). Ga68 PET or SSTR PET are common descriptors for the entire process regardless of the compound. Clearly the scan works best for those with ‘somatostatin receptor positive’ tumours.

These newer agents have several benefits over the elderly In111-pentetreotide (Octreotide scan), including improved detection sensitivity, improved patient convenience due to the 2-3 hour length of the study (compared to 2 or 3 days with Octreoscan), decreased radiation dose, decreased biliary excretion due to earlier imaging after radiotracer administration, and the ability to quantify uptake. The quantification of the uptake can help decide whether a patient is suitable for radionuclide therapy such as PRRT. Eventually, all Octreotide scans should be replaced with SSTR PET but it will take some time (and money).

Octreoscan vs Ga68 PET

To confirm the advantages of SSTR PET over Octreotide scans, a study comprising 1,561 patients reported a change in tumour management occurred in over a third of patients after SSTR PET/CT even when performed after an Octreotide scan. Worth pointing out that SSTR PET is replacing the ageing Octreotide scan and not conventional imaging (CI). You can see the recommended scenarios for use of SSTR PET in this article published by the Journal of Nuclear Medicine. The slide below is interesting, although it was a small study. However, you can see the treatment changes as a result of a Ga68 PET are quite striking.

This slide from a NET Research Foundation conference confirms the power of more detailed scanning

Any pitfalls with Ga68 PET Scan?

When you look at the study data above, it looks like an excellent addition to the diagnostic and surveillance toolkit for NETs. However, one of the challenges with modern scanning equipment and techniques is the ability to correctly interpret the results – in my opinion, this is almost as important as the efficiency of the machines and radionuclides. This requirement has been acknowledged in many articles and I particularly like this technical paper from a very experienced nuclear medicine physician Professor Michael Hofman from the Centre for Cancer Imaging at the Peter MacCallum Cancer in Melbourne. I had a chat with Professor Hofman who added that this is a very sensitive scan, so often picks up “new” disease, which isn’t really new, just never identifiable on standard imaging. However, there’s an excellent section on pitfalls in interpretation and I’m quoting an abstract below.

“Although GaTate PET/CT is a highly sensitive and specific technique for NETs, the attending physician or radiologist must be aware of various physiologic and other pathologic processes in which cellular expression of SSTR can result in interpretative error. Most of these processes demonstrate low-intensity and/or nonfocal uptake, in contrast with the focal intense abnormality encountered in NETs. Causes of interpretative pitfalls include prominent pancreatic uncinate process activity, inflammation, osteoblastic activity (degenerative bone disease, fracture, vertebral hemangioma), splenunculi or splenosis, and benign meningioma.”

“The highest-intensity physiologic uptake of GaTate is seen in the spleen, followed by the adrenal glands, kidneys, and pituitary gland”

It follows that failure to interpret nuclear scans alongside the patient’s clinical history can sometimes result in two big issues for patients:

1. Unnecessary worry when ‘something’ shows up which is actually a false positive.

2. Something which leads to irreversible treatment when it is was not required.

Just imagine something which is 40 times better than current PET scan technology? That’s what the scientists are working on now. Here’s an example called “EXPLORER“. You can update yourself here. The issue of interpretation will be even more difficult when the new generation of scans appear. There’s an excellent article from Cancer Research UK talking about the modern phenomenon called ‘overdiagnosis’ – read here

Lanreotide and Octreotide and timing the scan?

From the same technical document referred above, here’s an extract (updated to include Lanreotide). “Uptake at physiologic and pathologic sites may change in patients who undergo concomitant short- or long-acting somatostatin analog therapy, which competes with the radiotracer for bioavailability. We generally discontinue short-acting octreotide for 12–24 hours and perform imaging in the week before the next dose of long-acting Octreotide/*Lanreotide, which is typically administered monthly“.  It’s actually the same text as found in the manufacturer’s drug leaflet (click here). More evidence behind the reason for this restriction is found here (please refer to the comments on Ga68 PET – the article also covers the issue of PRRT which is very interesting as a separate subject to the scan timings).

*added by the author for completeness.

Having my first Ga68 PET Scan after 8 years of  living with NETs? 

When I was offered my very first Ga68 PET/CT at my recent 6 monthly surveillance meeting, I was both excited and apprehensive. I was diagnosed in 2010 and my staging was confirmed via an Octreotide Scan pointing out two further deposits (one of which has since been dealt with). I’ve had two further Octreotide Scans in 2011 and 2013 following 3 surgeries. The third scan in 2013 highlighted my thyroid lesion – still under a watch and wait regime. So far, my 6 monthly CT scans seemed to be adequate surveillance cover and my markers remain normal.

I’m apprehensive because of the ‘unknown’ factor with cancer – what is there lurking in my body that no-one knows about and which might never harm me.

I’m excited because it might just confirm that there is nothing new to worry about.

However, I’m both excited (morbidly) and apprehensive because the scan might find something potentially dangerous. As we know, NETs are mostly slow growing but always sneaky. That said, at least I will know and my medical team will know and be able to assess the risk and decide on a course of action.

Doing the Scan

On 5th June 2018, I attended a very experienced Ga68 PET establishment called Guys Cancer Centre in London.  I arrived and was immediately taken under the wing of the nuclear medicine guys who asked me fairly in depth questions about my clinical background.  They then inserted a cannula ready for the injection of the radiolabelled tracer.  I was then installed in the ‘hot room’ where they injected the radionuclide tracer through the cannula and then I had to remain in the hot room for 1 hour to let the tracer circulate.  After 1 hour, I was taken to the PET scanner and it took around 30-35 minutes. Following that I was allowed to leave for home.  It was an extremely easy experience and a significant improvement on doing the 3 day Octreotide scan.

20180605_141229

Door to the ‘hot room’

The Results of the Ga68 PET Scan – CLICK HERE

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!

 

Neuroendocrine Cancer – surveillance and follow up

surveillance

If I had a pound for every time I’ve said “make sure you get good surveillance and follow up”, I’d have a lot of pounds! Most Neuroendocrine Tumours are slow-growing and they can be difficult to diagnose due to their sneaky nature. Some can be just as sneaky beyond diagnosis though. The best way to combat that is through regular surveillance or ‘follow-up’. There are actually guidelines and recommendations for follow-up on the main NET specialist societies such as ENETS, NANETS and UKINETS.  There’s others including in USA, the NCCN also have a set (and no surprises that the different organisation guidelines can often differ due to the healthcare systems in place). For more detailed or the latest guidelines content, you may need a login or in one instance (ENETS) a membership subscription.

The type and frequency of surveillance will depend on a number of factors, including but not limited to; NET type, primary location, stage and grade.  Worth also noting that these are guidelines and physicians will often take many factors into account in deciding on the frequency and content of follow up surveillance.

Let me also tell you that there isn’t really total common ground on exactly what that should be, although to be fair there’s much more agreement than disagreement. There’s even occasional mentions of “not enough data” to be able to say what the surveillance should be in certain scenarios – it’s not an exact science. So surveillance can be anything from monthly to recommended intervals such as 3 months, 6 months, 12 months, 3 years and I’ve even read something which said “no specific follow-up strategy has been recommended” (e.g. ENETS “curative resection of an Appendiceal NET less than 1cm by simple appendectomy“).  Often a patient will need to advocate to get the right attention.  Knowing what the guidelines are for your situation is a good start.

So what sort of surveillance might be needed?

I think the definition of surveillance is actually wider than the guidelines infer. In addition to the planned follow-up surveillance, I also think there are checks that might be described as ‘opportunistic’. A simple example … if a nurse visits you at home, he or she might ask how things are. Similarly if you visit a GP/PCP, this could be an opportunity to assess the issue you are having against your medical history. Again, if you call your NET specialist or NET Specialist Nurse, this could be another opportunity to assess a problem, albeit over the phone. The other surveillance I would like to see more ‘formalised’ would be the surveillance of the consequences of cancer and it’s treatment – this is a huge unmet need in many cancers.  Examples include (but are not limited to) the issues of vitamin & mineral deficiencies and gastrointestinal malabsorption.

However, the documented and objective surveillance methods are really important and can be very similar to those which were used to diagnose you. These are…..

Scanning

Scanning is very important because the locations of tumours should already be documented and can therefore be tracked, or in the case of an unknown primary, continue to look.  Scans are looking for tumours or suspicious objects and any progression of known tumour sites. There are different scans for different purposes and even for different parts of the body and NET type.  Check out my article If you can see it – you can detect itclick here.  The Ga68 PET scan is becoming more available – click here.

scans for nets

Tumour Markers and Hormone Levels

You will have baseline test results which will be compared at each planned surveillance opportunities. Whilst there are common tests available, some types of NETs may need particular tests, especially if you have one or more of the NET Syndromes producing one or more of the offending hormones.  These tests may even be required on an ad hoc basis if symptoms worsen. I have a fairly comprehensive article on this subject – click here.  It’s also possible that a new biopsy might be necessary (perhaps following a scan) and this may even lead to a new grading on the basis that the score might turn out be higher than the baseline grade.

markers

Misc Tests

NETs are a heterogeneous group of malignancies so I guess some people have additional tests alongside their main tumour markers and hormone levels.   I have the routine blood levels alongside my markers, that’s pretty standard I think.  I also get my thyroid levels checked due to a lesion currently under watch and wait.  Read about his here.  Due to surgery and malabsorption issues, I also get regular vitamin checks, in particular B12 and D.  Read here to see why this is important.  As someone who was initially diagnosed with ‘Carcinoid Syndrome’ alongside my NET, I normally get an annual Echocardiogram to check for Carcinoid Heart Disease – they had removed that earlier this year from my surveillance but it’s now back as a precaution due to the discovery of some fibrosis growth in my retroperitoneal area.   You may also be monitored for ‘at risk’ or comorbidity checks such as the thyroid.

Listen to your body

I also have a personal theory that patients are doing surveillance on a daily basis. For example, I actually maintain a diary briefly listing things such as sleeping patterns, what I’ve eaten, bathroom activity, weight, and some other stuff including particular comorbidities that might or might not be related (if not, then it’s also useful for any resulting GP/PCP appointment). That sounds like a lot of work but actually only takes me one minute each day. I’m really looking for patterns.  If I think there is a pattern or a connection, I take this data to any appointment or contact the NET Nurse for advice or even just a sounding board. I can’t beat up my medical team for not spotting something where my input would have been important.  I already learned that lesson prior to diagnosis.

Summary

A lot of people don’t like living in a surveillance society.  Me?  I’m perfectly happy about it – it will keep me alive longer.  And if ‘Big Brother’ is a NET specialist, even better!

Always ask what your follow-up regime will be – this cancer can be SNEAKY.

Thanks for reading

You may also enjoy my article “10 Questions to ask your Doctor” – click here.

Thanks for reading

The Invisible NET Patient Population 

The Invisible NET Patinet Population

OPINION

 

I found some of the quotes from the recent NET SEER Database study (Dasari et al) very interesting.  The National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program is a comprehensive source of population-based information initiated in 1973 that is updated annually. Although the study is US-based, it represents the largest study of Neuroendocrine Tumors (NETs) ever recorded and is therefore a good guide to what might be found beyond USA. In fact, other national declarations of incidence and prevalence of NETs seem to bear these statistics out, i.e incidence rates of 7-8/100,000 …… almost 7 times the rate recorded in the 1970s. If you want to understand the factors behind this massive increase, I covered this extensively in my post “Neuroendocrine Tumors – not as rare as you think“.  In this article, I looked at USA and beyond. Those who are regular readers of my articles will already know I’ve been ‘banging on’ about this for a few years. Other organisations and individuals (including NET specialists) are now indicating these tumors are not rare, some vindication for my aforementioned ‘banging on’.  This is now a serious disease with some serious statistics behind it and we need a new way of doing things.

 There are two further quotes which I’d like to focus on in this article:

1. From the NET SEER Database study published 2017:

…… many cases of NETs may not have been reported to cancer registries unless considered malignant…… it is likely that we have underestimated their true incidence and prevalence” – i.e. the slide here:

SEER 2012 Underestimated

2. From Dana Farber (Kulke, Chan):

“Estimated more than 200,000 undiagnosed cases in the US” – this slide here:

dana-farber-200000

…. But what do these quotes actually mean?  Here’s my take:

Underestimating the true incidence and prevalence of NETs

I studied the latest SEER NET study, formally titled “Trends in the Incidence, Prevalence, and Survival Outcomes in Patients With Neuroendocrine Tumors in the United States” (authored by Arvind Dasari, MD, MS; Chan Shen, PhD; Daniel Halperin, MD; et al). From this document, I can see the authors were aware of the well-known faults in cancer registries worldwide and the effect this has on the true incidence and prevalence of Neuroendocrine Cancer.  These issues, which are a worldwide problem, include the incorrect registration of Neuroendocrine Cancer as other types based on the anatomical location of the primary tumor.  At this point, you may wish to check out my post “The Human Anatomy of Neuroendocrine Cancer” which provides some real life examples of the confusion between primary Neuroendocrine location and other cancers. That said, things are definitely improving because the latest SEER data shows a marked increase in the incidence of High Grade Neuroendocrine Carcinomas (NEC), an area where this issue is prevalent. A similar increase in NEC was also illustrated in the UK’s figures from Public Health England (PHE) in 2016 (click here) indicating that cancer registries are getting better and not before time, although it has to be said this only came about due to a major intervention by NET Patient Foundation and others. Through this work, it’s becoming clear that the incidence of all NETs in UK is around 8 to 9 per 100.000 (rare threshold <=5).

But there’s another issue impacting whether a diagnosis is actually entered on a cancer registry or not.  Unfortunately, there are members of the medical community who still see well differentiated NETs as benign tumors, ‘not a proper cancer’ and still use ancient terminology ………  ‘Carcinoid’.  The WHO 2010 classification for NETs was based on the concept that all NETs have malignant potential. Here’s a quote from the UKINETS Guidelines in 2011 (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 WHO 2017 for Endocrine Organs reinforces this statement.

The undiagnosed NET patient population

From above, you can see why the incidence (and therefore the prevalence) of our disease has almost definitely been underestimated.  However, that’s not the end of my story……..

A number of statements are clear about Neuroendocrine Tumors:

  • Low/Intermediate grade well differentiated tumors are known to have been growing slowly over a number of years before discovery or accurate diagnosis occurs,
  • They can be difficult to diagnose,
  • They are not that well-known amongst the general medical population,
  • Many people are initially misdiagnosed with another condition, with some this will result in late presentation with metastatic disease.
  • Many NETs are found during autopsies.

The living undiagnosed. It’s worth pointing out that one of the conclusions made by the recent SEER NET study is that the increase in incidence and prevalence can be attributed to a number of factors including earlier diagnosis.  This is of course excellent news.  Also worth noting that another conclusion of the study is that we are all living longer, reflecting improvements in therapies.  This is also great news and is a factor in increased prevalence figures. However, it seems obvious that there are hundreds of thousands of people out there still be diagnosed who have tumors silently growing inside them and who are in a loop of referrals between primary and secondary care awaiting a proper diagnosis. See the Dana Farber slide above.  Please help these people by sharing this article (you never know who it will reach – Diagnosing the Undiagnosed.

The dead undiagnosed? The true incidence of NETs may be much higher owing to the lack of diagnosis until after death.  For example:

  • In USA, a respected NET specialist stated that the autopsy find for (excuse the outdated terminology…….) ‘carcinoid‘ is 4 times the recorded diagnosis rate (based on the known incidence rate at the time, this is 8 per 100,000).
  • In Australia, one study claimed that 0.05% of all autopsies found a Pheochromocytoma or Paraganglioma. “
  • The Mayo Clinic experience shows that in up to 50% of cases of pheochromocytoma, the correct diagnosis is made at autopsy (ergo the incidence rate could be double what is published).
  • Here is an article claiming that former US President Dwight D Eisenhower had a biopsy confirming he had a Pheochromocytoma.  Click here.
  • A Hong Kong study indicated that 1% of all autopsies discovered an ‘Islet Cell’ tumour (i.e. a Pancreatic NET or pNET).
  • In one series, (excuse the outdated terminology…….) ‘carcinoid’ tumors were found in 1.22% of 16,294 autopsies in Malmö, Sweden, 90% of which were incidental findings.

It’s possible that many of these people showed no NET symptoms during their life but …… it’s equally possible that many of these people had NET symptoms but just put up with it and/or had been diagnosed with something else, and then died without a correct diagnosis.  There is no evidence that any investigation follow ups were done so this possibility remains.

The potential for even more undiagnosed. To add to the underdiagnoses of NETs issue, is this most amazing piece of research published in 2018 – Pan-cancer molecular classes transcending tumor lineage across 32 cancer types, multiple data platforms, and over 10,000 cases.  It was published in the American Association of Cancer Research (AACR) journal ‘Clinical Cancer Research and authored by Chad Creighton et al. D.  This was a pan-cancer piece of research which indicated that Neuroendocrine disease may be more prevalent than anyone has ever thought.  There’s a summary article here which I suggest you read fully.  The rather explosive extract is as follows:

We expected that about 1 percent of

Are you undiagnosed but suspect NETs?

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Summary

I suspect there’s an invisible patient population for many conditions but the slow-growing and relatively quiet nature of Neuroendocrine Cancer means there could be a significant undiagnosed burden walking around, looking for a diagnosis, putting up with symptoms and being treated for other conditions. I see people on forums looking for clues, social media can sometimes be helpful here. That said, I do get the feeling some do not have NETs, regardless of the symptoms they associate with the disease, but I guess many of them will go on to be formally diagnosed with something. I’m contacted by many ‘undiagnosed’ people on my own blog and supporting Facebook sites (mostly privately) and I can tell you that’s a tough gig.  I only hope I’ve given them some useful ideas about where to look or what to ask/suggest.

I feel earlier diagnosis reported in the SEER study is partly due to increased awareness, particularly in the medical world. I would also suggest that it has improved in the general population due to the explosion of social media information dissemination. It’s also accurate to say that improvements in diagnostic capabilities is also playing its part in pushing up incidence rates, just as improved therapies have pushed up prevalence rates, something emphasised by Dasari (et al) in the most recent study.  Things are improving but there is so much more to do.

The issues caused by inefficient registries together with ‘the undiagnosed’, combine to suggest there is a large invisible NET patient population out there ……. we just need to find them!  

Thanks to NET Patient Foundation for featuring this article here.

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