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?

Check out my advice by clicking here.

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.

NET Patient Foundation logo

Neuroendocrine Tumor Drug Clinical Trial – Cabozantinib (includes news on Pheochromoctyoma and Paraganglioma)

What is Cabozantinib?

Cabozantinib is an oral drug which works by blocking the growth of new blood vessels that feed a tumour. In addition to blocking the formation of new blood cells in tumours, Cabozantinib also blocks pathways that may be responsible for allowing cancers cells to become resistant to other “anti-angiogenic” drugs. It is a type of drug called a growth blocker.  Cabozantinib has been studied or is already in research studies as a possible treatment for various types of cancer, including prostate cancer, ovarian cancer, brain cancer, thyroid cancer, lung cancer, and kidney cancer. During my research, I found that it has a connection to Medullary Thyroid Cancer (MTC) which is a type of Neuroendocrine Cancer, frequently associated with Multiple Endocrine Neoplasia (MEN).  Cabozantinib, under the brand name of ‘Cometriq’ was approved by the FDA in 2012 for use in MTC.  Read more about Cometriq here.  It’s also been approved by the FDA for advanced renal cell carcinoma (RCC) (branded as Cabometyx). I also discovered that there is an exclusive licensing Agreement with the manufacturers (Elelixis) and Ipsen (of Lanreotide fame) to commercialize and develop Cabozantinib in regions outside the United States, Canada and Japan

Growth blockers are a type of biological therapy and include tyrosine kinase inhibitors, proteasome inhibitors, mTOR inhibitors, PI3K inhibitors, histone deacetylase inhibitors and hedgehog pathway blockers.  Cabozantinib is a tyrosine kinase inhibitor (TKI).  They block chemical messengers (enzymes) called tyrosine kinases.  Tyrosine kinases help to send growth signals in cells so blocking them stop the cell growing and dividing.  Some TKIs can block more than one tyrosine kinase and these are known as multi-TKIs.

cabozantinib-picture
Example action of Cabozantinib

So Capozantinib is a tyrosine kinase inhibitor and is therefore a biological therapy and growth blocker just like Everolimus (Afinitor) and Sunitinib (Sutent) – some texts describe thelattero two as chemotherapy but this is just not accurate.

Very technical process but in the simplest of terms, Cabozantinib is designed to disrupt the actions of VEGF (a growth factor) and MET (a growth factor receptor) which promote spread of cancerous cells through the growth of new blood vessels.  Whilst we are on this subject, please note Everolimus (Afinitor) is an mTOR inhibitor and Sunitinib (Sutent) is a tyrosine kinase inhibitor. Many people think these drugs are a type of chemo – that is incorrect, these are targeted biological therapies.  See more on this by clicking here.

What is the current trial status of Capozantinib?

A Phase III trial is now recruiting entitled Cabozantinib S-malate in Treating Patients With Neuroendocrine Tumors Previously Treated With Everolimus That Are Locally Advanced, Metastatic, or Cannot Be Removed by Surgery”. 

The trial has 172 locations across the US (see link below). The primary study (final data) is scheduled Jan 1st 2021.

You can read the trial documentation by clicking here.

Progress report

  1. Poster submission for 2017 Gastrointestinal Cancer Symposium
  2. Onc Live output from the 2017 Gastrointestinal Cancer Symposium
  3. Output from NANETS 2017
  4. A funded piece of research by the NET Research Foundation – check it out herelooks like they are trying to figure out what patients might benefit from Cabozantinib using biomarker data to predict response.
  5. Dr Jennifer Chan speaking in 2018 about the drug potential.  (Apologies for the use of the out of date term ‘Carcinoid‘).
  6. Phase 3 Clinical Trial Document – click here

————————-

UPDATED 2018 – There’s also another trial looking at unresectable metastatic Pheochromocytomas and Paragangliomas

A Phase 2 Study to Evaluate the Effects of Cabozantinib in Patients with Unresectable Metastatic Pheochromocytomas and Paragangliomas 

This part is from an article collaboration between MedPage Today® and the American Association of Clinical Endocrinologists

BOSTON — Cabozantinib (Cabometyx) may benefit patients with malignant pheochromocytomas and paragangliomas, according to results of a phase II trial presented here.

Patients receiving cabozantinib (Cometriq) treatment experienced notable tumor shrinkage in the lymph nodes, liver, and lung metastases, according to Camilo Jimenez, MD, of the MD Anderson Cancer Center in Houston, and colleagues.

Additionally, progression-free survival significantly increased after treated to 12.1 months (range 0.9-28) compared with just 3.2 months prior to treatment, they reported at the American Association of Clinical Endocrinologists (AACE) annual meeting.

Cabozantinib treatment was also tied to an improvement in blood pressure and performance status, as well as remission of diabetes among these patients.

“Malignant pheochromocytomas and paragangliomas are frequently characterized by an excessive secretion of catecholamines. [Patients] have a large tumor burden and they have a decreased overall survival,” explained Jimenez. “Tumors are frequently very vascular and frequently associated with bone metastases. In fact, up to 20% of patients who have malignancy of pheochromocytomas and paragangliomas may have predominant bone metastases.”

He added that “an interesting aspect of this tumor is that C-MET receptor mutation have been found in occasional patients with malignant pheochromocytomas and paragangliomas.”

Cabozantinib is an anti-angiogenic tyrosine kinase inhibitor, which also targets RET, MET, and AXL. It is approved for metastatic medullary thyroid cancer, and was more recently approved for first-line treatment of advanced renal cell carcinoma.

“MET pathway is also involved in the development of bone metastases. In fact, cabozantinib is a very effective medications for patients who have bone metastases in the context of cancer of different origins,” Jimenez said.

In order to be eligible for the trial, patients with confirmed pheochromocytoma or paraganglioma had to be ineligible for curative surgery, have ≥3 months life expectancy, no risk for perforation or fistula, and adequate organ functioning. Prior to cabozantinib initiation, patients could not receive chemotherapy or biologic agents within 6 weeks, radiation within 4 weeks, or MIBG within 6 months.

Following histological confirmation of disease progression >1 year according to RECIST 1.1, the trial included 14 patients with measurable disease and eight patients with predominant/exclusive bone metastases. Fifteen patients subsequently enrolled into the trial, six of whom had germline mutations of the SDHB gene.

All participants were all started at an initial daily dose of 60 mg of cabozantinib, which was subsequently reduced down to between 40 to 20 mg due to toxicity in 13 patients based on tolerance.

The majority of these patients with measurable disease experienced some level of disease response. Six patients reported a partial response, defined as over a 30% reduction, while three patients achieved moderate response, marked by a 15%-30% reduction. Five of the patients with predominant bone metastases reported disease stabilization, according to results of an FDG-PET scan. One patient experienced disease progression while on treatment.

Overall, cabozantinib was generally well-tolerated without any grade 4 or 5 treatment-related adverse events reported. Some of the most common adverse events reported included grade mild dysgeusia, hand and foot syndrome, mucositis, fatigue, weight loss, and hypertension, according to the authors.

  • Primary Source – American Association of Clinical Endocrinologists meeting – AACE 2018; Abstract 142. attended my Medscape writers

You can see the Pheo/Para clinical trial document by clicking here.

————————————–

Summary

I generated this blog article to add value rather than just post the outputs for your own perusal.  I hope you find it useful.

Please note that taking part in a clinical trial is a big decision and must be considered carefully in conjunction with your specialists if necessary.  This article is not suggesting this trial is right for you.  Please check the inclusion and exclusion criteria in the trials document carefully. (Pheo/Para patients see other clinical trial link above)