Neuroendocrine Cancer – on your bike!

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There’s a Brit saying known as “on your bike” (sometimes colloquially called “on yer bike“).  It basically means “go away and stop bothering me” but there are other definitions including some ‘Anglo-Saxon’ versions (I won’t repeat those here!)

When I moved to my current home nearly 7 years ago, the removals lorry unloaded our rather dusty bikes (pedal cycles) and stuffed them in the garage where they mostly remained until this year.  A couple of months ago, I dusted them off, repaired punctures etc, and basically started putting them to better use.  In fact, Chris got a new one out of the deal! I’m reasonably fit (considering) but finding it so easy to opt for the sofa and there’s always something worth watching on TV, or something to do on my computer.  My personal trainer (Chris ♥) tends to provide some motivation, so it felt good that the recent bike idea came from me rather than from her.

However, some of the personal motivation came from a recent ‘brush’ with potential diabetic problems.  My blood glucose test has been spiking in the last 12-18 months and an HbA1c in May (a better guide) put me just inside pre-diabetic range. This prompted me to look more carefully at diet and exercise. I need to do this without losing too much weight though, I’m still struggling to put the weight back I that I lost from the June chest infection.

I have so say I’m enjoying my new exercise and have had some nice bike rides in the local forests.  I’ve since had a new HbA1c test which is back in normal range so I guess something is making it spike.  Lanreotide is my first guess – you can read more about Diabetes and NETs by clicking here.

I’m working with my doctors on the issue.

In the meantime, I’m getting on my bike and so can Neuroendocrine Cancer!

Exercise – it’s a free prescription.

Thanks for reading

Ronny

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Neuroendocrine Cancer: Somatostatin Receptors

ct compare to g68 pet
CT and G68 PET fused showing somatostatin receptor pick up

Don’t understand Somatostatin Receptors?  Join the club!  I got my head around the term ‘Somatostatin’ and ‘Somatostatin Analogues’ some time ago but the term ‘Somatostatin Receptor’ (SSTR) is still a bit of a mystery and it’s come to the top of my list of things to study.  SSTRs do come up in conversation quite often and I’m fed up of nodding sagely hoping it will eventually become clear! On analysis it looks like a technical subject – and therefore a challenge 🙂

I’ve taken a logical approach working from ‘Somatostatin’ to ‘Somatostatin Analogue’ before commencing on the ‘receptor’ bit.  It is intentionally brief and (hopefully) simplistic!

Somatostatin

It’s important to understand this hormone and then why your ‘butt dart’ is generically called a ‘Somatostatin Analogue’.

Some Neuroendocrine Tumours secrete hormones and peptides that cause distinct clinical syndromes, including amongst others, carcinoid syndrome.  Somatostatin is a naturally occurring hormone and a known inhibitor of some of these NET related hormones and peptides that can be over secreted and cause syndromes. For example, somatostatin from the hypothalamus inhibits the pituitary gland’s secretion of growth hormone (GH) and Thyroid Stimulating Hormone (TSH). In addition, somatostatin is produced in the pancreas and inhibits the secretion of other pancreatic hormones such as insulin and glucagon.  However, the naturally produced Somatostatin does not have the lifespan to have any effect on Neuroendocrine Tumours which are over secreting these hormones and peptides. ……. cue manufactured versions that can!

Somatostatin Analogue (SSA)

These are manufactured versions of Somatostatin known as Somatostatin Analogues.  These are designed to have a lasting effect to inhibit for much longer and therefore reduce the symptoms caused by the over secretion (i.e. the syndrome).  Examples of Somatostatin Analogue include Octreotide (Sandostatin), Lanreotide (Somatuline) and Pasireotide (Signifor).

So how do Somatostatin Analogues actually work? 

For the inhibition to work effectively, there needs to be a route into the over secreting tumours, normally via short or long acting injections or even intravenously. On the tumour cells, there are currently 5 known sub-types of ‘Somatostatin Receptors’  (SSTR) which are ‘expressed’ by most NETs.   These are known as SSTR1 through to SSTR5.  The naturally occurring hormone Somatostatin attempts to bind with all 5 but as above, it lacks the lifespan to make any impact to inhibit sufficiently in cases of overecretion. However, SSAs can overcome this with the longer lifespan.  They can successfully in most cases bind with these receptors to inhibit the hormones and peptides causing the problems, particularly SSTR2 with modest affinity to SSTR5. Clearly it’s therefore advantageous to target SSTR2.

Somatostatin Receptors

The subtypes expressed by NETs are variable and the efficiency of different SSAs in binding to each SSTR subtype also varies. For example the table below lists the variability of Somatostatin Receptor efficiency in different types of NET.  Interesting to note that non-functional NETs might not have efficient SSTRs but SSAs will still try to bind to them albeit it might not work or have a lesser effect.

Somatostatin receptors are found in high numbers on the surface of NET’s. Most receptors are in the inactive state (based on something called the phosphorylation status). Traditionally, agents such as dotatate have only bound to activated receptors on the surface.  Scientists are looking at ways to bind to inactive receptors to increase therapy success (for example see clinical trial OPS 201)

Table 1 – Somatostatin receptor subtypes in neuroendocrine tumours (mRNA) (See Copyright)

Tumour SSTR1 (%) SSTR2 (%) SSTR3 (%) SSTR4 (%) SSTR5 (%)
Gastrinoma 79a 93 36 61 93
Insulinoma 76 81 38 58 57
Non-functioning pancreatic tumour 58 88 42 48 50
Gastro-intestinal NET 76 80 43 68 77

This table above clearly shows the variability of SSTRs when binding with different types of NETs.  It follows that manufacturers of SSAs will be using this data in the formulation of their drugs.  If you now look at the table below, you can see how efficiently the 3 well-known SSAs inhibit NETs on each SSTR.

Compound SSTR1 SSTR2 SSTR3 SSTR4 SSTR5
RECEPTOR SUBTYPE AFFINITY (IC50, nM)
Octreotide 1140 0.56 34 7030 7
Lanreotide 2330 0.75 107 2100 5.2
Pasireotide 9.3 1 1.5 >100 0.16

View it in a separate window

You can see from the data why Octreotide and Lanreotide target SSTR2 and to a lesser extent SSTR5 but Pasireotide (Signifor or SOM-230) is interesting as it appears to have affinity for SSTRs 1-3 and 5, probably why it has been approved for Cushing’s Disease (ATCH producing).  However, to date, there has not been enough evidence showing that Pasireotide has a progression-free survival benefit over the other 2 therapies. It is also associated with hyperglycemia. You may find this video interesting as the doctor (Strosberg) is suggesting it could be used by NET patients in certain scenarios.

What about SSA labelled diagnostics?

The same principles apply.  For example, an Octreotide Scan (actually known as ‘Somatostatin Receptor’ Scintigraphy (SRS)) works by taking pictures using a gamma camera which is designed to see radiation from a ‘tracer’.  The tracer in question is a radio labelled with an Octreotide variant (such as pentetreotide) which will bind to somatostatin receptors on the surface of the tumour cells  In the simplest of terms, this shows up where NETs are.  The same principles apply to Ga 68 PET scans which are more advanced and more sensitive than SRS.

What about SSA labelled therapies?

With (say) Peptide Receptor Radiotherapy (PRRT), there is a similar binding mechanism going on.  In PRRT, Octreotide or a variant, is combined with a therapeutic dose of the radionuclides, e.g. Yttrium 90 (Y-90) and Lutetium 177 (Lu-177).  It binds with the SSTRs on the tumour cells and the therapeutic dose attacks the tumour having been brought there by the binding effect.  Simple isn’t it?

Do Somatostatin Receptors work for everyone?

Unfortunately not.  Some people have more sensitive receptors than others and the figure of 80% appears to be the most common statistic indicating one-fifth of all NET patients may not be able to respond correctly to SSA treatment or get the right results from Octreoscans/Ga 68 PET and/or PRRT.  However, that needs to be taken into context and probably applies to midgut NETs measured against SSTR2 – the tables above tend to confirm this figure.  During my research, I did read that higher than normal doses of SSAs may have some effect on those with less sensitive SSTRs.  Also, SSAs seem to work much better with well-differentiated tumours.

How do I know if my Somatostatin Receptors work?

When I was completing my NET checks after diagnosis, my Oncologist declared I was “Octreotide avid” shortly after my Octreoscan was compared with my CT.  I’m guessing that is a simple and crude test and how most people find out they have working receptors.  I also suspect that if your syndrome symptoms are abated somewhat by SSA injections, then you there is a good chance your SSTRs are working normally.  I also suspect those who show clear signs of tumour on CT but not on Octreoscan or Ga 68 PET, could have a receptor issue.

The advent of modern PET scanning (e.g. Ga68) has meant more accurate methods of working out if someone has the right receptors for PRRT through analysis of something known as standardized uptake values (SUV).

A more modern approach is to use a ‘Theranostic Pair” where the same radiolabelled tracer is used with the advantage that the diagnostic element can predict suitability for the therapy component  – read more here

lutathera owl - Copy


Somatostatin Receptor Research – Interest Point

I was please to see a piece of research ongoing to look at the issues with lack of somatostatin receptors.  The research is looking at novel imaging agents for NETs which do not have working receptors.  Read more here.

Summary

I hope this gives you a very basic outline of why Somatostatin Receptors are important to support the diagnosis and treatment of NETs.

My article “If you can see it, you can detect it” is almost 100% accurate but having working receptors really helps with nuclear scans.

Preclinical and clinical studies have indicated that somatostatin receptor (SSTR)expressing tumors demonstrate higher uptake of radiolabeled SSTR antagonists than of the currently approved SSTR agonist versions. See clinical trial OPS 201 for an example of the next generation of somatostatin receptor based theranostics where the use of a somatostatin antagonists.

thanks for reading

Lanreotide – it’s calling the shots!

Lanreotide calling the shots

2019 UPDATE:

Please note a new syringe for Lanreotide will be available in 2019, at least in Ireland and UK which have confirmed dates.  However, Ipsen are committed to roll it out to the rest of Europe, US, Canada, Australia and New Zealand by end of 2019 (details to follow)  following necessary regulatory approvals.

Further information will be communicated to healthcare professionals in advance of this, to enable them to inform their patients, whom have been prescribed Lanreotide. In addition, the patient information leaflet included in the packet will have clear instructions for use. There will be a prominent yellow box located on the outer carton of the medicine, alerting healthcare professionals and patients that a new syringe is contained inside.

The new pre-filled syringe for Somatuline® Autogel® was the result of several studies, involving patients, their caregivers, nurses and other healthcare professionals, to inform and test enhancements to the existing pre-filled syringe. Notable new features are modified ergonomics and handling, a needle shield removal system, an injection process with plunger support and heightened ease of use. The automatic, built-in safety system, which helps to prevent needle stick injury by locking in place following the administration, has not been changed.

Please note that the medicine is still the same and the formulation and storage conditions have not changed.

new lanreotide
Diagram of new injection system for Lanreotide (hopefully actual photo to follow once I get my hands on one)

My Lanreotide Experience

When I was discharged from hospital following major surgery in Nov 2010, I knew I would shortly be commencing long-term monthly ‘somatostatin analogue’ treatment and had assumed Octreotide (Sandostatin LAR) would be the drug of choice. However, my Oncologist prescribed Lanreotide (known in the UK as Somatuline Autogel and elsewhere as Somatuline Depot).  Technically this is a hormone therapy (it’s not chemo).

Somatostatin Analogues (Octreotide/Lanreotide) are mainstay treatments for many Neuroendocrine Cancer patients and their introduction is a very significant factor in the improvement of both prognostic outcomes and quality of life.  Both drugs are designed to control Carcinoid Syndrome (but can be used selectively in other NET syndromes) and both have anti-tumour effects.  Check out my Lanreotide vs Octreotide comparison blog.

butt dart with words

Although I didn’t relish the thought of any injection in the ‘rear end’ every 28 days for the rest of my life, I admit to being slightly relieved with his choice.  I had been reading about patient experiences with the alternative, mainly the needle length and the occasional problems mixing the drug prior to injection.  Although Lanreotide has a similar gauge (thickness), the needle is a good bit shorter and is deep subcutaneous rather than Octreotide LAR’s intramuscular (IM) route. No mixing is required as Lanreotide comes prefilled.

If you’re interested in the science, please be aware that a somatostatin analogue is a synthetic (manufactured) version of a naturally occurring hormone which inhibits the peptides and amines that can be dangerously hypersecreted by certain neuroendocrine tumours.

Following an Octreotide Scan, various areas lit up confirming the output from previous CT scans.  It also confirmed new ‘hotspots’ for further investigation.  This specialist scan confirmed I probably had working receptors to receive something known as a Somatostatin Analogue to help with combatting the effects of Carcinoid Syndrome (please note that not having working receptors does not mean there is no benefit of receiving somatostatin analogues). I was therefore prescribed daily Octreotide (self-injecting) whilst I was waiting for my first major ‘debulking’ surgery, This treatment did eventually lessen the main effect of the carcinoid syndrome, facial flushing.  It wasn’t until after my first surgery that the facial flushing was dramatically reduced.  I commenced Lanreotide on 9 Dec 2010 and I haven’t had a facial flush since. It’s worth adding that my Chromogranin A (CgA) blood test (correlated to tumour mass) did not return to normal until after a liver resection 3 months later.  My 5HIAA urine test results (mainly correlated to serotonin levels) returned to normal prior to liver surgery in Apr 2011 indicating the Lanreotide was doing its job! Somatostatin Analogue side effects are to be expected and most people seem to have different and/or greater or lesser effects than others. The daily Octreotide did not bother me too much other than some discolouring of the stomach at the injection sites (i.e. black and blue!) ….I’m more observant nowadays, so it’s possible I may not have recorded this experience properly.

If you read the UK patient leaflet which comes with each injection, you can see a list of potential side effects as long as your arm.  Neuroendocrine Cancer comes with many signs, syndromes, symptoms and suspicions, so I always advise caution and some analysis when assigning reasons for problems encountered.  For North America, the equivalent instructions can be found here (Somatuline Depot). I don’t know precisely why (……. I do have my suspicions), but I’m always very sceptical about the criteria used to compile the list of side effects for any medicine. In my own mind, I’m fairly certain that people have existing symptoms or new symptoms as a result of coincidental treatment that are erroneously labelled under drugs during trials.

You can also self-inject Lanreotide but I’m not ready for that yet!  If you do self inject, please note it the site is “the upper outer part of your thigh”.  Check out the Ipsen leaflet here.

I think the injection site is very important and getting this wrong will worsen the side effects. For the Healthcare Professional or trained family member administration, the site should be the superior external quadrant but not of the whole ‘butt’, it means of the left or right buttock that is being used on an alternative basis.  If nurses think the whole ‘butt’, they might be tempted to stick it quite close to the ‘intergluteal cleft’ – not advisable!

Although the patient leaflets are very clear on how to administer the drug, once the location is established, I always discuss the following with the Nurse before I receive the ‘dart’:

1.  The injection should have been removed from the fridge at least 30 minutes before treatment. However, please note Ipsen clarified in 2019 that the product can be put back in the fridge in the original packaging for later use, provided it has been stored for no longer than 24 hours at below 40 deg C (104 deg F) and the number of ‘temperature excursions’ does not exceed three. If you are taking the drug somewhere to be administered or were waiting on a home visit, this might help with scheduling issues.

2.  Don’t pinch the skin, stretch it.

3.  Put the needle in fast at 90 degrees, inject the drug slow – 20 seconds is recommended. As the drug is viscous, in any case, there is normally some resistance to a fast release.

4. Do not rub or massage the area after as this action can interfere with the formulation of the drug.  This is clearly stated on the drug information leaflet, i.e. ” Apply gentle pressure to the injection site with a dry cotton ball or sterile gauze to prevent any bleeding. Do not rub or massage the injection site after administration”.

My experience with side effects.  People have different experiences with side effects and just because a particular side effect is mentioned, does not mean to say that everyone will be troubled – many patients experience little or none.  For me, over 7 years, I think I can attribute the following to Lanreotide:

  • itching but only on the legs below the knees centred on the ankles – and nearly always the right leg.  Occasionally, the injection site will itch but only for a day or two.  I have a tub of emollient cream (almond oil) on standby which seems to calm it down.  Note …… a little bit of me thinks there could be a connection with vitamin/mineral deficiency and perhaps a coincidental occurrence and this problem seems much less of an issue over 7 years later. EDIT- could have been Hypothyroidism – click here.
  • minor pain at the injection site but this only lasts for an hour or two and I believe this to be associated with the administration of the injection, i.e. if the injection is done properly, I don’t really have this problem except for a second or two as it enters.  Once, I had pain for 10 days.  In my own experience, the best and least painful injections are those done by trained personnel who are confident.
  • small lumps form at the injection site which is alternating superior external quadrant of the each buttock. You may occasionally hear these being called ‘granulomas‘ or ‘injection site granulomas’. The issue of ‘injection site granulomas’ seems to figure in both Lanreotide and Octreotide. Gluteal injection site granulomas are a very common finding on CT and plain radiographs. They occur as a result of subcutaneous (i.e. intra-lipomatous) rather than intramuscular injection of drugs, which cause localised fat necrosis, scar formation and dystrophic calcification. But no-one seems to know why they occur with somatostatin analogues. I find that they are more conspicuous if the injection is done slightly too high which was my initial experience and they took months to fade.  I opted to stand up for the first two injections and I attribute this decision for a slightly too high injection site.  I now lie down which is actually recommended for the smaller and thinner patient. Although the lumps have reduced in size, I have not seen a new lump for some time indicating location might have been the cause. They sometimes show up on scans.  This is not a new problem and has been highlighted for the last 10 years in academic papers.  This particular paper is useful and the conclusion confirms this is not something that should worry patients too much. Read more here
  • fatigue normally within 24-48 hours of the injection but this is not consistent. Not even sure it can be classed as proper fatigue but it’s a ‘you need to sit down and fall asleep‘ feeling! When this occurs, it normally only lasts for 1 day before the normal energy levels return.  Again, like the itching, this appears to be less of an issue today.
  • malabsorption. although the side effects of gastro-intestinal (GI) surgery and gallbladder removal can cause malabsorption issues leading to steatorrhea (basically the inability to digest fat properly); somatostatin analogues can cause or exacerbate existing steatorrhea, as they inhibit the production of digestive/pancreatic enzymes which aid fat digestion.  Most months, I notice a marked but short-term increase in this problem normally within 48-72 hours of the injection.
  • elevated blood glucose.  This is a new issue in 2018 but has been brewing for a year or two. The patient information leaflet for Lanreotide (and for Octreotide) clearly states that this is a potential side effect and also asks those who are already diabetic, to consult their doctor about monitoring doses of diabetic medicine.  I’m working with my doctors to keep my blood glucose down to avoid becoming diabetic.  Please read this article covering the connections between NETs and Diabetes

Watch a useful injection demonstration video here (for administration by a healthcare professional or family member) (click here)

A few years ago, there was some ‘talk’ that somatostatin analogues were also able to stunt or reverse the growth of certain neuroendocrine tumours.  Has this been the case for me?  Possibly.  I’ve had regular CT scans every 3-6 months and since two bouts of major surgery in 2010/2011, I’ve also had 3 x Octreoscans over the same period.  I did once spend a day analysing 5 years of scan results looking for variations in size and concluded that there was a stable trend and potentially a fading of one or two of my largest liver tumours. I was reminded these two types of scans were not really precise enough to detect small millimetre increases or decreases and as there were other factors at play, there was little commitment to make this declaration.  However, I did note in the summary of the CLARINET study, Lanreotide was associated with prolonged progression-free survival among patients with advanced, grade 1 or 2 (Ki-67 <10%) enteropancreatic, somatostatin receptor–positive neuroendocrine tumours with prior stable disease, irrespective of the hepatic tumour volume.  In terms of its anti-proliferative effects, an interim report from the CLARINET extension study suggested longer-term Lanreotide treatment is well tolerated with ‘anti-tumour’ effects in patients with progressive disease.  The final CLARINET open label extension study report additionally provided evidence for long-term PFS benefits of Lanreotide Autogel 120 mg in patients with indolent pancreatic and intestinal NETs.

There’s currently a trial ongoing in relation to Lanreotide and Lung NETs – read by clicking here.

I have my ups and downs and I do feel quite well most of the time.  Most people tell me I look quite well too – lucky they can’t see my insides!  Over the last 7 years, I’ve made some fairly significant adjustments to cope with my condition and maintain a reasonable quality of life – my monthly injection of Lanreotide is no doubt playing a big part.

Finally, please spend 5 minutes watching this fascinating video from Ipsen.  It explains in easy terms how Lanreotide works.  It also has a useful summary of the side effects at the end.  Click here to watch the video.

I’ve just been enrolled onto a new service called HomeZone whereby the injection is now administered at my home via an Ipsen provided and funded nurse.  Read here to see if you can also take advantage of this service.

THE SOMATULINE ‘RESERVOIR’ FORMING IN THE DEEP SUBCUTANEOUS TISSUE

In July 2018, I received my 100th injection of Somatuline Autogel (Lanreotide).  I was very grateful to still be here so I thought it was worth a celebratory cake – injection themed!

Cake with Needle

CAKE PHOTO1 WITH NURSE2

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Ronny

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